Airworthiness Directives; NavWorx, Inc. Automatic Dependent Surveillance Broadcast Universal Access Transceiver Units, 25946-25954 [2017-11625]
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Federal Register / Vol. 82, No. 107 / Tuesday, June 6, 2017 / Rules and Regulations
the availability of this material at NARA, call
202–741–6030, or go to: https://
www.archives.gov/federal-register/cfr/ibrlocations.html.
Issued in Renton, Washington, on May 23,
2017.
Michael Kaszycki,
Acting Manager, Transport Airplane
Directorate, Aircraft Certification Service.
[FR Doc. 2017–11289 Filed 6–5–17; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2016–9226; Directorate
Identifier 2016–SW–065–AD; Amendment
39–18910; AD 2017–11–11]
RIN 2120–AA64
Airworthiness Directives; NavWorx,
Inc. Automatic Dependent Surveillance
Broadcast Universal Access
Transceiver Units
Federal Aviation
Administration (FAA), DOT.
ACTION: Final rule.
AGENCY:
We are adopting a new
airworthiness directive (AD) for
NavWorx, Inc. (NavWorx), Automatic
Dependent Surveillance Broadcast
(ADS–B) Universal Access Transceiver
Units (unit). This AD requires removing,
disabling, or modifying the ADS–B unit.
This AD was prompted by a design
change that results in the unit
communicating unreliable position
information. The actions in this AD are
intended to address an unsafe condition
on these products.
DATES: This AD is effective July 11,
2017.
SUMMARY:
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Examining the AD Docket
You may examine the AD docket on
the Internet at https://
www.regulations.gov by searching for
and locating Docket No. FAA–2016–
9226; or in person at the Docket
Operations Office between 9 a.m. and 5
p.m., Monday through Friday, except
Federal holidays. The AD docket
contains this AD, Supplemental Type
Certificate (STC) No. SA11172SC, the
economic evaluation, any comments
received, and other information. The
street address for the Docket Operations
Office (phone: 800–647–5527) is U.S.
Department of Transportation, Docket
Operations Office, M–30, West Building
Ground Floor, Room W12–140, 1200
New Jersey Avenue SE., Washington,
DC 20590.
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Kyle
Cobble, Aviation Safety Engineer, Fort
Worth Aircraft Certification Office
(ACO), Rotorcraft Directorate, FAA,
10101 Hillwood Pkwy, Fort Worth, TX
76177, telephone (817) 222–5172, email
kyle.cobble@faa.gov; or Michael
Heusser, Program Manager, Continued
Operational Safety Branch, Fort Worth
ACO, Rotorcraft Directorate, FAA,
10101 Hillwood Pkwy, Fort Worth, TX
76177, telephone (817) 222–5038, email
michael.a.heusser@faa.gov.
SUPPLEMENTARY INFORMATION:
FOR FURTHER INFORMATION CONTACT:
Discussion
On October 20, 2016, at 81 FR 72552,
the Federal Register published our
notice of proposed rulemaking (NPRM),
which proposed to amend 14 CFR part
39 by adding an AD that would apply
to NavWorx ADS–B Model ADS600–B
units, part number (P/N) 200–0012 and
P/N 200–0013, and Model ADS600–EXP
units, P/N 200–8013. The NPRM
proposed to require removing the ADS–
B unit before further flight and proposed
to prohibit installing the affected ADS–
B unit on any aircraft. The NPRM was
prompted by a design change that
resulted in the ADS–B units
broadcasting a Source Integrity Level
(SIL) of 3 instead of 0. A broadcast of
SIL 0 is required because of the
uncertified Global Positioning System
(GPS) source included in the unit. The
proposed actions were intended to
prevent an ADS–B unit from
communicating unreliable position
information to Air Traffic Control (ATC)
and nearby aircraft and a subsequent
aircraft collision.
Comments
We gave the public the opportunity to
participate in developing this AD. We
received approximately 200 comments,
mostly from individuals but also from
NavWorx and organizations such as the
Aircraft Owners and Pilots Association
(AOPA), the Experimental Aircraft
Association (EAA), and the Aircraft
Electronics Association (AEA). The
following presents the comments
received on the NPRM and the FAA’s
response to each comment.
A. Support for the NPRM
Five individual commenters
supported the NPRM.
B. Comments Regarding the FAA’s
Justification of the Unsafe Condition
Several commenters, including
AOPA, requested that the FAA provide
more information about the events that
prompted this AD and the technical
aspects surrounding the unsafe
condition. We agree.
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Request: AOPA requested the FAA
clarify whether the internal position
source in the ADS–B units meets the
performance requirements in Appendix
B to Advisory Circular (AC) 20–165B. In
support of this request, AOPA stated the
FAA’s contention that NavWorx did not
present any data substantiating its SIL
change is contrary to NavWorx’s public
statements that its testing verified the
position source met the integrity levels
required by the regulations. Similarly,
NavWorx commented on the AD and
maintained it has provided the FAA
with data demonstrating the internal
GPS met the requirements to transmit a
SIL of 3.
FAA Response: NavWorx has not
demonstrated to the FAA that the
internal position source meets the
performance requirements in Appendix
B to AC 20–165B 1 for a SIL of 3. The
design specifications for NavWorx’s P/N
200–0012 and 200–0013 ADS–B units
identify the internal GPS source for
those units as an uncertified SiRF IV
GPS. The SiRF IV is a commercial grade
chipset not manufactured under an FAA
Technical Standard Order (TSO). AC
20–165B requires the SIL be set at 0
when the ADS–B is integrated with an
uncertified GPS source. When NavWorx
submitted its software upgrade changing
the SIL value from 0 to 3, no hardware
design changes associated with the SIL
value change were made to the ADS–B
units and no testing data substantiating
that SIL change was provided to the
FAA. The only justification NavWorx
cited for the software change was the
FAA’s termination of Traffic
Information Service—Broadcast (TIS–B)
services to aircraft broadcasting ADS–B
with a SIL of 0. This data is available
for review in Docket No. FAA–2016–
9226.
Request: AOPA requested the FAA
clarify its meaning of ‘‘uncertified GPS
source’’ since NavWorx has design
approval through STC No. SA11172SC
to install the ADS–B unit with the
internal GPS on type-certificated
aircraft, and since a compliant position
source does not need to meet a specific
TSO to meet the requirements set forth
in Appendix B of AC 20–165B.
Some commenters requested the FAA
explain why it approved NavWorx’s
ADS–B units at all if the internal,
uncertified GPS source is objectionable.
Many commenters stated the NavWorx
ADS–B units meet the performance and
accuracy/integrity standards of TSO C–
154c; others noted that NavWorx has
stated its testing showed the units meet
the requirements to broadcast a SIL of
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3. Several commenters disagreed with
the AD because the GPS source is not
required to be certified separately from
the ADS–B unit.
FAA Response: The commenters,
including NavWorx, are correct that the
position source only needs to meet
certain performance requirements and
does not need to be certified under a
TSO. However, despite NavWorx’s
statements and comments to the
contrary, NavWorx has presented no
data to the FAA—test plans and test
results—that demonstrate the affected
units with the internal SiRF IV GPS
meet the performance standards to
transmit a SIL of 3. Similarly, NavWorx
has never demonstrated to the FAA that
the affected units meet the 14 CFR
§ 91.227 requirements to broadcast a SIL
of 3 when using the internal SiRF IV
GPS.
NavWorx’s TSO–C154c authorization
and STC were approved based on the
P/N 200–0012 and 200–0013 units
broadcasting a SIL of 0 when using the
internal uncertified GPS position
source. NavWorx documented this as a
limitation in the Aircraft Flight Manual
Supplement (AFMS) for NavWorx’s STC
for ADS600–B installations. Section 2.6
of the AFMS, titled ‘‘Uncertified GPS
Receiver (P/N 200–0012 and 200–
0013),’’ states:
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The ADS600–B has an internal uncertified
GPS WAAS receiver which does not meet the
14 CFR 91 FAA–2007–29305 rule for certified
GPS position source. If the ADS600–B is
configured to use the internal uncertified
GPS as the position source the ADS–B
messages transmitted by the unit reports: A
Source Integrity Limit (SIL) of 0 indicating
that the GPS position source does not meet
the 14 CFR 91 FAA–2007–29305 rule.
While 14 CFR § 91.227 requires a SIL
of 3, TSO–C154c (the TSO under which
the affected units are produced) does
not. Thus, when the affected units
broadcast a SIL of 0, they are TSOcompliant. Until the performance
requirements of 14 CFR § 91.227 become
effective on January 1, 2020, the FAA
does not find the internal uncertified
GPS source objectionable, as long as the
ADS–B unit is correctly broadcasting a
SIL of 0. It is NavWorx’s change of the
SIL setting in these units to 3, without
any qualification of the internal
uncertified GPS position source to
support broadcast of SIL 3, that the FAA
finds unacceptable. In this condition,
the units are transmitting to ATC and to
nearby aircraft that they have 14 CFR
§ 91.227-compliant position source
integrity, when their position source
integrity is actually not compliant with
that rule, or is unknown. We discuss the
safety effects of this condition in greater
detail below.
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Request: AOPA requested the FAA
further explain its finding that the
affected units create an unsafe
condition. Many commenters
questioned the FAA’s determination
that the units present an unsafe
condition, and asked whether any units
have actually caused a collision or
safety incident. Many other commenters
stated they have been operating with the
NavWorx unit and find it accurate and
reliable. Several commenters stated the
NavWorx units increase safety and
noted that the National Transportation
Safety Board has recommended ADS–B
units to the flying public.
FAA Response: The FAA’s safety
concern is primarily that of integrity,
and not necessarily accuracy, with
respect to the NavWorx ADS–B unit’s
performance requirements. Accuracy
refers to the probability of the unit’s true
position in relation to its reported
position.2 Integrity refers to the trust
that can be placed in the correctness of
the information provided by the unit
and is specified by a SIL value. The SIL
value is set based on design data from
the GPS position source manufacturer
and reflects the probability that the
position source will provide incorrect
data without providing an alert. This
depends on whether the GPS has fault
detection and exclusion, where the
equipment will detect a faulty satellite
and exclude it from the navigational
calculations. If the GPS does not have
fault detection and exclusion, the
probability that the position source will
provide incorrect data increases.
Commercial position sources, such as
the SiRF IV GPS used in the NavWorx
P/N 200–0012, 200–0013, and 200–8013
units, do not have fault detection and
exclusion capabilities. This is
significant in the event a GPS satellite
signal fails or a GPS ‘‘signal-in-space
error’’ occurs.
The unsafe condition relates to the
potential for the NavWorx unit to
incorrectly report its own position to
other aircraft and to ATC, by 0.2
nautical miles (NM) or more, without
providing an alert.3 It may also result in
ATC providing incorrect and
inappropriate separation instructions or
traffic advisories to other aircraft for
avoidance of the ADS600–B-equipped
aircraft, based on the erroneous position
2 Accuracy of an aircraft’s reported position is
specified as Navigation Accuracy Category for
Position, or NACP. A unit that complies with 14
CFR 91.227 has a NACP corresponding to an
accuracy of better than 0.05 nautical miles. The
NavWorx units’ compliance with the 14 CFR 91.227
NACP (accuracy) performance requirements is not
the concern that prompted this AD.
3 0.2 NM is the minimum integrity containment
radius around the aircraft’s reported position
required by 14 CFR § 91.227 (c)(1)(iii).
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being reported by the ADS600–B. In this
situation, the pilot of the ADS600–Bequipped aircraft would be unaware
that his or her aircraft’s ADS–B Out unit
is broadcasting an erroneous position
(possibly in excess of 0.2 NM), since the
ADS600–B would not be providing an
alert for this condition. Depending on
operating conditions, these effects may
occur in instrument meteorological
conditions where see-and-avoid is not
possible. In view of these factors, this
condition poses an unacceptable hazard
to other users of the National Airspace
System (NAS).
Although there have been no reported
cases of a collision or safety incident
resulting from an incorrect transmission
by a NavWorx ADS–B unit to date, the
potential for the unsafe condition exists
as long as the units mislead ATC and
nearby aircraft by broadcasting a SIL of
3 that they have not been shown to
meet. This AD action addresses that
potential unsafe condition.
The fact that commenters have made
flight tests with satisfactory ADS–B
performance monitor reports from the
FAA, or that commenters’ individual
units have been operating successfully,
does not negate the existence of an
unsafe condition. Flight tests with the
ADS–B performance monitor are
designed primarily to show that the
ADS–B equipment in an individual
aircraft performs correctly as installed.
These tests are of relatively short
duration and occur in fault-free
conditions. They are not engineering
tests designed to evaluate the unit’s
ability to handle GPS signal-in-space
errors and cannot be used to draw
inferences about the unit’s position
source integrity.
Although the FAA recognizes the
benefits of ADS–B equipage and
understands that the NavWorx units
may work a large percentage of the time
for an individual user, the FAA must
consider the effect on the entire NAS.
Since failure is based on a statistical
probability, the odds that a unit will
have a failure increase as more units are
introduced into the NAS and operate for
a longer period of time. The probability
of a failure also increases when there is
a GPS satellite malfunction, which
could affect many aircraft since the
information is used by ATC and ADS–
B In equipped aircraft for separation.
Therefore, despite any benefit to
individual owners when the unit works
without failure, the FAA has
determined that an unsafe condition
with the NavWorx units exists and
requires corrective action because of the
hazard they pose to other users of the
NAS.
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Request: AOPA requested the FAA
produce for public inspection the Small
Airplane Risk Analysis (SARA)
documentation.
FAA Response: As part of our risk
assessment, we initially performed a
SARA. However, the SARA assumes
failure on one airplane. The issue with
the NavWorx ADS–B units poses risk to
the NAS. Specifically, a malfunction at
the satellite level could result in
transmission of hazardously misleading
position information from the ADS600–
B-equipped aircraft to ATC and to other
aircraft. It could also cause such
malfunctions in all aircraft with the
affected ADS–B units installed that are
using the signal from the
malfunctioning satellite to determine
their position. Thus, we determined the
SARA results provided questionable
value, and that it was more appropriate
to use the safety risk methodology from
the ADS–B program, as documented in
Safety Risk Management Document
(SRMD) Critical Services: Standard
Terminal Automation Replacement
System (STARS) with Automatic
Dependent Surveillance Broadcast
(ADS–B) Only Addendum, SBS–036C,
Revision 1, dated August 26, 2014
(SBS–036C).
In SBS–036C, we analyze safety risk
as a composite of two factors: The
potential ‘‘severity’’ or worst possible
consequence or outcome of an adverse
effect that is assumed to occur, and the
‘‘likelihood’’ of occurrence for that
specific adverse event. We assess both
factors independently and then enter
each as separate inputs into a risk
matrix, which yields an overall level of
risk for the event as Low (acceptable),
Medium (acceptable with mitigation), or
High (unacceptable). The corrective
action, if any, is driven by the assessed
overall risk. Figure ES–1 of SBS–036C
contains the risk matrix the FAA used
for this AD.
The FAA considered an undetected
position error event of 0.2 NM or more
for a single aircraft as a ‘‘Position error
outside containment bound for single
aircraft undetected by airborne
equipment/ground automation’’ hazard,
which has a classified severity of
‘‘hazardous’’ per Table ES–1 and
Appendix B of SBS–036C. Hazardous is
defined in AC 23.1309–1E, System
Safety Analysis and Assessment for Part
23 Airplanes,4 as resulting in a large
reduction in safety margins, physical
distress or higher workload, or serious
or fatal injury to an occupant other than
the flight crew. A large position error
(0.2 NM or more) may lead to loss of
4 https://rgl.faa.gov/Regulatory_and_Guidance_
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separation, increased ATC workload, a
reduction in safety margins, and a near
midair collision. These are unsafe
conditions that warrant a ‘‘hazardous’’
severity level for risk assessment
purposes.
From Table ES–1 of SBS–036C, the
likelihood of this failure for a properly
functioning system was assessed as
extremely improbable. Figure ES–1 in
SBS–036C is a risk matrix that yields an
overall risk based on the severity
classification and the assessed
likelihood of occurrence. A severity
classification of ‘‘hazardous’’ and an
assessed likelihood of ‘‘extremely
improbable’’ yields an overall risk of
‘‘Low,’’ which is an acceptable risk.
However, the likelihood assessment of
‘‘extremely improbable’’ in Table ES–1
is based on the aircraft’s GPS receiver
having either fault detection or fault
detection and exclusion, which is
required in order to meet the ADS–B
Out position integrity requirements of
14 CFR 91.227. A GPS receiver with
fault detection detects a faulty satellite
signal and provides an alert of the fault.
If the GPS receiver has fault detection
and exclusion, it additionally excludes
the faulty satellite signal from the
position computation. Because the GPS
position source in the NavWorx
ADS600–B units has no demonstrated
fault detection or exclusion features, the
FAA determined the appropriate
likelihood should be based on the GPS
constellation fault rate of 10¥4 per hour
(that is, a probability of 0.0001
occurrences per flight hour). As a result,
the FAA elevated the risk of the hazard
and assessed a likelihood of ‘‘remote.’’ 5
Using the severity classification of
‘‘hazardous’’ and an assessed likelihood
of ‘‘remote’’ yields an overall risk of
‘‘High’’ in Figure ES–1. This is an
unacceptable risk.
These determinations are documented
in the meeting minutes from the FAA’s
Corrective Action Review Board (CARB)
held on September 19, 2016. In
accordance with FAA Order 8110.107A,
Monitor Safety/Analyze Data, the CARB
considered this safety issue on that date
and determined that an unsafe
condition existed with the units. This
documentation is available for review in
Docket No. FAA–2016–9226.
Comment: A few commenters,
including NavWorx, noted the FAA
approved software revisions 4.0.7, 4.0.8,
and 4.0.9, which included the software
5 Although the CARB assessed a likelihood of
‘‘remote,’’ Figure 2 of AC 23.1309–1E assesses a
likelihood between ‘‘remote’’ and ‘‘probable,’’
depending on the class of aircraft, for a probability
of 10 minus;4. Either likelihood classification
would yield a High overall risk on the Figure ES–
1 risk matrix.
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changes for the units to broadcast a SIL
of 3.
FAA Response: The commenters are
correct that the FAA approved
NavWorx’s software changes identified
as 4.0.7, 4.0.8, and 4.0.9. However, none
of these changes identified on
NavWorx’s submittals affected the SIL
value or referenced the SIL value change
in 4.0.6. The FAA’s approvals did not
alter the FAA’s previous written
statements to NavWorx advising the
equipment must report a SIL of 0 to
remain compliant with TSO–C154c.
This documentation is available for
review in Docket No. FAA–2016–9226.
C. Requests To Allow Alternative
Actions
Request: Many commenters, including
AOPA, requested that, since the internal
GPS is the issue with the NavWorx unit,
the AD allow the ADS–B units to use an
external GPS position source or,
similarly, that the AD not apply to units
using an external GPS position source.
FAA Response: We agree. The only
external GPS position source approved
by the FAA for interface with the
ADS600–B is the Accord NexNav mini
LRU GPS Receiver P/N 21000 (Accord
external GPS).6 We revised the AD to
allow interfacing the ADS–B unit with
an Accord external GPS as an optional
corrective action. For operators who
wish to interface with other external
position sources, under the provisions
of paragraph (f) of this AD, we will
consider requests for approval of an
Alternative Method of Compliance
(AMOC) if sufficient data is submitted
to substantiate that the unit would
provide an acceptable level of safety.
Request: Several commenters,
including AEA, requested the AD allow
disabling the unit rather than removing
it.
FAA Response: We agree. We revised
the AD to allow disabling the unit as an
optional corrective action.
Request: Several commenters,
including AOPA, requested the AD
allow changing the SIL from 3 to 0 as
an alternative to removing the unit.
FAA Response: We agree. We did not
include this option in the NPRM
because NavWorx has stated it will not
provide its customers with software to
change the SIL to 0. However, we
revised the AD to allow changing the
6 Some commenters stated or implied that other
external GPS sources, such as the Garmin 530W, the
Garmin GNS 430W, the Garmin GNS 480, and the
Garmin GTN 650, are approved for installation in
the ADS600–B. Contrary to any documentation
these commenters may have from NavWorx, the
only FAA-approved external GPS source is the
Accord NexNav mini P/N 21000. Documentation of
this is available for review in Docket No. FAA–
2016–9226.
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SIL to 0 as an alternative to removing
the unit in the event such software
becomes available and is approved by
the FAA.
Request: One commenter requested
that the AD not apply to units with
software versions prior to 4.0.6, because
these units broadcast a SIL of 0 and thus
are not subject to the unsafe condition.
FAA Response: We agree. We
considered excluding units with
software prior to version 4.0.6 when we
issued the NPRM. We did not exclude
them because our understanding of the
units is that there is no recordkeeping,
marking, or indication from the unit
itself that allows an operator to identify
the current software version. However,
changes to the AD in response to other
comments render this exclusion
unnecessary.
Request: AOPA requested that we
allow the units to remain in service if
NavWorx upgrades the internal position
source with a position source that meets
the requirements of Appendix B to AC
20–165B. Similarly, several commenters
requested that we allow NavWorx to recertify the unit.
FAA Response: We agree. Should
NavWorx upgrade its internal position
source with a position source that meets
the performance requirements of
Appendix B to AC 20–165B, or
demonstrate that the internal SiRF IV
GPS meets those requirements, under
the provisions of paragraph (f) of this
AD, we will consider requests for
approval of an AMOC.
Request: Several commenters
requested that we allow more time for
compliance. Two of those commenters
requested that we delay compliance
until 2020, when the ADS–B operational
rules become effective.
FAA Response: We agree with
extending the compliance time. We
determined that safety will be
maintained if the corrective actions are
implemented within six months of the
effective date of the AD, and we revised
the AD accordingly.
We disagree with delaying
compliance until 2020. The FAA’s
ADS–B ground station network is
already operational and in use by ATC
nationwide, and ADS–B In is also
widely used in general aviation aircraft
for traffic awareness. Therefore, the fact
that ADS–B Out will not be required
equipment until 2020 does not negate
the unsafe condition that exists from
those units currently operating in the
NAS.
Request: Many commenters requested
that the FAA withdraw the NPRM and
instead work with NavWorx to address
the unsafe condition. Some commenters
inferred a failure by the FAA in this
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regard because it appeared it took the
FAA six months to respond to
NavWorx’s design change notification.
A few commenters expressed
disappointment and outrage at the
FAA’s handling of the certification
process with NavWorx and requested
we constructively and immediately
resolve this situation.
FAA Response: We agree it is
desirable to work with manufacturers to
resolve differences of opinion regarding
product compliance and correct
identified safety concerns. The FAA
made numerous efforts, in a variety of
forms and over a considerable period of
time, to resolve this situation with
NavWorx. Those efforts were
unsuccessful.
After receiving NavWorx’s design
change, the FAA advised NavWorx that
it could not manufacture the units as
TSO C–154c units because NavWorx
had not provided acceptable data to
substantiate modifying the SIL value of
the internal SiRF IV GPS to 3. Initially,
NavWorx agreed to return the SIL to 0
and requested 60 days to effect this
change. Instead, over two months later,
NavWorx informed the FAA that it
would not be returning the SIL value to
0 after all. The FAA continued to advise
NavWorx, both verbally and in writing,
that the SIL change rendered the units
non-compliant with the TSO. The FAA
also continued to request that NavWorx
voluntarily return the SIL to 0, but
NavWorx refused. The FAA met with
NavWorx and explained the means of
compliance in our existing guidance for
certifying the SiRF IV GPS to broadcast
a SIL of 3, as well as the process for
submitting an alternate or equivalent
means of compliance for approval.
While NavWorx indicated its desire to
initiate one of those processes, it did
not. Instead, NavWorx continued to sell
and ship the part-numbered 200–0012
and 200–0013 units with the
unapproved design change, and
continued to furnish product software
upgrades through its Web site to
existing owners that contained the
unapproved design change. When the
FAA repeatedly requested to conduct a
routine inspection of NavWorx’s
facility, in part to review NavWorx’s
units and data supporting its design
change, NavWorx refused.
After determining the situation
created by NavWorx resulted in an
unsafe condition, and without
NavWorx’s cooperation to correct the
unsafe condition, the FAA found it
necessary to issue an AD.
Documentation of these events is
available for review in Docket No. FAA–
2016–9226.
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Request: One commenter requested
the FAA allow a temporary, alternative
solution in which operators would
periodically validate the units by flight
test.
FAA Response: We disagree.
Validation flight tests are not
engineering tests and are not designed
to evaluate the unit’s position source
integrity. The commenter’s requested
method of compliance would not
correct the unsafe condition.
Request: One commenter requested
we exclude ADS–B units that are
already installed from the requirements
of the AD.
FAA Response: We disagree. The FAA
has determined an unsafe condition
exists on the affected ADS–B units and
that removal or correction of the units
is required.
Request: Two commenters request the
AD not apply to aircraft operating under
visual flight rules (VFR).
FAA Response: We disagree. The FAA
has determined that an unsafe condition
with the NavWorx units exists and
requires corrective action because of the
hazard they pose to other users of the
NAS. The NavWorx unit broadcasting a
SIL of 3, when it is only authorized to
broadcast a SIL of 0, has the potential
to incorrectly report its own position to
other aircraft and to ATC by 0.2 NM or
more, without providing an alert. Even
in visual meteorological conditions, this
could result in the pilot of another
aircraft visually searching the wrong
sector of sky for the incorrectly
reporting ADS600–B-equipped aircraft
or incorrectly assessing the ADS600–Bequipped aircraft as not being a
collision threat, based on the depicted
relative position of the ADS600–B
aircraft on its ADS–B In traffic display.
Request: EAA and two individual
commenters requested the AD not apply
to experimental or light sport aircraft,
since they are not regulated in the same
manner as type-certificated aircraft.
EAA states the FAA should address any
valid airworthiness concerns with parts
intended for experimental aircraft
through a Special Airworthiness
Information Bulletin (SAIB) or safety
alert for operators (SAFO). Two
commenters requested the AD apply to
experimental aircraft, because those
aircraft operate in the same airspace as
type-certificated aircraft and should use
equipment with the same integrity. A
few commenters, including AOPA,
requested we clarify whether the AD
applies to experimental aircraft.
FAA Response: We agree to clarify
this issue. We confirm that the AD
applies to all aircraft, including
experimental, and we revised the AD to
clarify the applicability. We made this
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AD applicable to the ADS600–EXP P/N
200–8013 units because the design of
the Model ADS600–EXP P/N 200–8013
is substantially identical to the Model
ADS600–B P/N 200–0012 and 200–
0013, specifically with regard to the
internal GPS and the SIL setting. While
some commenters are correct that the
FAA has chosen to minimize
regulations on experimental aircraft
because of the level of the safety risk,
these risks normally apply to the
individual airplane and do not affect the
overall NAS. The safety risks defined in
this AD extend beyond one aircraft and
could affect many other aircraft as well
as ATC. Therefore, we find it necessary
to include experimental aircraft in the
AD’s applicability.
We do not agree that an SAIB or
SAFO would be an appropriate solution.
These documents contain information
and recommended actions that are
voluntary and not regulatory. Moreover,
an SAIB is issued only for airworthiness
concerns that do not rise to the level of
an unsafe condition.
The mission of the FAA is aviation
safety. ADs are used by the FAA to
correct known safety defects. It would
be contrary to the intent of the FAA’s
mission and statutory authority to
exclude certain aircraft when we have
determined that a part installed on those
aircraft has a safety problem.
D. Comments Regarding Costs of
Compliance With This AD
Request: Many commenters stated
that the cost to comply with this AD is
underestimated or inaccurate and
requested the FAA revise its cost
estimate. These commenters stated the
cost should include the cost to replace
the unit with a new ADS–B unit and
costs associated with loss of utility;
should increase the number of labor
hours to account for indirect costs such
as removal and reinstallation of
associated equipment, research, and
paperwork; and should increase the
labor rate.
FAA Response: We disagree. The cost
analysis in AD rulemaking actions
typically includes only the costs
associated with complying with the AD.
In this AD, the only required action is
the removal of the unit, the deactivation
of the unit, the coupling of the unit with
an approved external GPS source, or the
upgrading of the software in the unit to
broadcast a SIL of 0. These actions are
estimated to take 1 work-hour each,
except for coupling the unit with an
approved external GPS source, which is
estimated to take about 4 work-hours.
The costs of associated required actions
such as installing a placard or revising
the flight manual are nominal. ADS–B
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Out equipment is not required for
operation until January 1, 2020, and is
only required for operation in certain
specified airspace after that date.
Individual operators are in the best
position to determine whether they will
need to install this equipment for the
airspace they intend to operate in.
Therefore, replacement of the unit is not
necessary to comply with this AD.
The labor rate of $85 per hour is
provided by the FAA Office of Aviation
Policy and Plans for the FAA to use
when estimating the labor costs of
complying with AD requirements.
Request: Several commenters
requested the FAA revise its
determination that the AD is not a
significant regulatory action. One
commenter requested the FAA analyze
the costs of the AD under the Regulatory
Flexibility Act.
FAA Response: We disagree. An AD is
economically significant when the cost
may have an annual effect on the
economy of $100 million or more.7 Even
if we were to include labor for indirect
costs and the cost of replacing the unit
with a new unit in our estimate, at an
estimated cost of $10,000 per aircraft
and $8 million for the U.S. fleet over the
next three years, the AD would not rise
to level of economically significant. In
addition, ADs correct identified unsafe
conditions, rather than raise an already
adequate level of safety, and cannot be
assessed in terms of benefits balancing
costs, as would be the case for
rulemaking that amends airworthiness
standards.
The Regulatory Flexibility Act of 1980
(Pub. L. 96–354) (RFA) establishes as a
principle of regulatory issuance that
agencies shall endeavor, consistent with
the objective of the rule and of
applicable statutes, to fit regulatory and
informational requirements to the scale
of the businesses, organizations, and
governmental jurisdictions subject to
regulation. To achieve that principle,
the RFA requires agencies to solicit and
consider flexible regulatory proposals
and to explain the rationale for their
actions. The RFA covers a wide-range of
small entities, including small
businesses, not-for-profit organizations,
and small governmental jurisdictions.
Agencies must perform a review to
determine whether a proposed or final
rule will have a significant economic
impact on a substantial number of small
entities. If the agency determines that it
will, the agency must prepare a
regulatory flexibility analysis as
described in the RFA.
7 A ‘‘significant regulatory action’’ is defined in
Executive Order 12866 (58 FR 51735, October 4,
1993).
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However, if an agency determines that
a proposed or final rule is not expected
to have a significant economic impact
on a substantial number of small
entities, section 605(b) of the RFA
provides that the head of the agency
may so certify and a regulatory
flexibility analysis is not required. The
FAA did make such a determination for
this AD. The basis for this
determination is now discussed.
The FAA uses the Small Business
Association (SBA) criteria for
determining whether an affected entity
is small. For aircraft manufacturers,
aviation operators, and any business
using an aircraft, the SBA criterion is
1,500 or fewer employees.
NavWorx is a small entity, and this
AD could have an adverse impact on its
business interests. Besides NavWorx,
the largest number of affected small
entities would most likely be operators
of ADS600–B-equipped aircraft. Based
on the estimated number of units in
service, and assuming each unit is
owned by a different small entity, the
largest number of small entities affected
is 800.
The FAA estimates that there is a total
population of 210,000 general aviation
and air taxi aircraft in the United
States.8 Of these, approximately 70,300
(33.5%) are flown primarily for some
type of business or commercial use and
thus are potentially operated by a small
entity. Aircraft flown primarily for
personal use would not be operated by
a small entity as defined by the SBA.
The FAA assumed all 70,300
commercial use aircraft are operated by
small entities and that each small entity
operates an average of 6 aircraft,9 which
yields an estimated number of 11,700
small entities. We also assumed that of
the 800 affected units, 33.5% (270) are
used in commercial operations.10 This
8 Based on the FAA General Aviation and Air
Taxi Activity Survey for calendar year 2015 (the
most recent year of data available), table 1.2,
General Aviation and Air Taxi Number of Active
Aircraft by Primary Use. https://www.faa.gov/data_
research/aviation_data_statistics/general_aviation/
CY2015/media/2015_GA_Survey_Chapter_1_
Tables_16SEP2016V2.xlsx.
9 We based this assumption on the sanction
guidance in Appendix B of FAA Order 2150.3B,
FAA Compliance and Enforcement Program, which
classifies air carriers and operators by operating
revenue, pilots employed, and aircraft operated for
purposes of determining civil penalty amounts.
https://rgl.faa.gov/Regulatory_and_Guidance_
Library/.
10 This assumption in particular is grossly high.
First, some of the affected units are installed on
experimental aircraft, which are prohibited from
commercial operations and therefore could not be
used by a small entity under the RFA. Second, of
the approximately 200 comments we received on
the NPRM, only six commenters (NavWorx, a
charitable aircraft operator, and four avionics
installation businesses) could be presumed to be
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equates to a maximum of 2.3% (270/
11,700) of small entities affected by this
rule. This is not a substantial number of
small entities under the RFA.
Request: A few commenters requested
or implied the FAA fund the costs of the
AD.
FAA Response: We disagree. The
FAA, as a federal agency, is responsible
for all directives, policies, and mandates
issued under its authority. Although we
have determined that an unsafe
condition exists with the design change
to the ADS–B unit, the manufacturer is
responsible for the design change.
Additionally, the FAA’s budget does not
include allocations to cover AD costs
incurred in modifying privately-owned
equipment.
E. Comments to the FAA’s Rulemaking
Process
Request: Several commenters
questioned the FAA’s motive in
proposing the AD. Some believed that
the FAA is colluding with other ADS–
B manufacturers or industry
organizations. Others suggested the FAA
is unfairly targeting NavWorx and
would not be taking this action if it
involved a larger manufacturer. We
interpret these comments as requesting
we withdraw the NPRM.
FAA Response: We disagree. The FAA
has not communicated with any other
ADS–B product manufacturer or
industry organization regarding the
compliance or safety of NavWorx
products. In issuing this AD, we
followed established policy and
procedures, including the public notice
and comment procedures of the
Administrative Procedures Act, as well
as the DOT’s ex parte policy, which can
be found in Appendix 1 to 14 CFR part
11. We placed all ex parte comments in
the rulemaking docket and considered
all comments we received.
We also disagree that we are unfairly
targeting NavWorx. We have determined
an unsafe condition exists on a
NavWorx product and we are requiring
corrective action accordingly. If the
FAA identifies similar problems and
determines that an unsafe condition
exists on other ADS–B products,
whether manufactured by NavWorx or
other companies, we would take
appropriate action to correct the unsafe
condition.
Request: An individual commenter
questioned whether we intended to
issue an AD against ADS–B
transponders manufactured by Trig or
Dynon. According to the commenter,
the Trig transponder allows the installer
commercial entities. The remaining comments were
submitted by individuals.
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to manually set the SIL value, and the
commenter claims installers will
improperly set the SIL at 3 to obtain
traffic information. The commenter also
states the Dynon ADS–B uses the same
GPS source that is the subject of this
AD.
FAA Response: We are issuing this
AD to correct an unsafe condition that
we have determined exists on a
NavWorx product. This AD is not
applicable to Trig Avionics (Trig) or
Dynon Avionics (Dynon) ADS–B units.
In the case of the older Trig units,
installers are responsible for setting the
SIL appropriately based on the
qualification of the position source
used. Additionally, neither the Trig
units nor the Dynon units use the SiRF
IV position source.
Request: Several commenters noted
they purchased a NavWorx unit because
the FAA originally listed them as
eligible for the ADS–B Rebate Program.
We interpret these comments as
requesting we withdraw the NPRM.
FAA Response: We have considered
the comment. When the FAA rebate
program Web site activated, it listed the
ADS600–B as an eligible unit without
distinction by part number. This was
consistent with NavWorx’s Web site,
www.navworx.com, which advertised
the ADS600–B for sale without
distinguishing between the four
different unique transceiver part
numbers comprising that model series.
P/N 200–0112 and P/N 200–0113 are
2020 compliant, as these units contain
a TSO–C145c approved Accord NexNav
Mini internal GPS. P/N 200–0012 and P/
N 200–0013, which are the subject of
this AD, are not 2020 compliant because
these units contain the uncertified SiRF
IV GPS. Once the FAA rebate program
office realized that the P/N 200–0012
and 200–0013 units were not eligible for
the rebate, it changed the Web site to
identify the ADS600–B model by P/N
and listed only the P/N 200–0112 and
P/N 200–0113 units as ADS600–B
equipment selection options. While the
FAA regrets any inconvenience these
actions caused, what occurred with the
rebate program Web site is not relevant
to whether this AD is necessary to
resolve the unsafe condition presented
by the NavWorx units that improperly
transmit a SIL of 3. We did not change
the AD based on these comments.
Request: One commenter states the
proposed AD is contrary to the FAA’s
Compliance Philosophy because we did
not cooperate with NavWorx or provide
NavWorx a reasonable time to work on
a corrective action. The commenter
requests we withdraw the NPRM, unless
we can collect technical data confirming
a safety issue, in which case the
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25951
commenter requests any AD be issued
in a non-punitive manner.
FAA Response: We disagree. The
FAA’s Compliance Philosophy applies
to enforcement actions taken for
regulatory violations. It does not apply
to ADs, which are rulemaking actions
taken to correct unsafe conditions found
in aeronautical products.
Notwithstanding, we also disagree with
contentions that we failed to cooperate
with NavWorx or provide NavWorx
with a reasonable amount of time to
correct the unsafe condition. The FAA
clearly and repeatedly explained to
NavWorx the safety concerns with its
ADS–B units and requested that
NavWorx voluntarily make the units
TSO-compliant. NavWorx’s failure to do
so created an unsafe condition, for
which AD action is necessary.
Comment: An individual commenter
stated that owners of experimental
aircraft could simply remark the
affected part with a new part number so
that the AD wouldn’t apply. The
commenter reasoned that since the
builder of an experimental aircraft is
also the manufacturer, he could alter the
part to a new design and mark it with
a new part number.
FAA Response: If the FAA identifies
similar problems and determines that an
unsafe condition exists on other partnumbered ADS–B products, we would
take appropriate action to correct that
unsafe condition. Also, simply changing
the part number of the unit, without
performing any other corrective action,
will not correct the unsafe condition
that we have determined exists in the
unit. Since the unsafe condition remains
in the unit, operating an aircraft with
such a unit (that has only had the part
number modified with no other
corrective action taken) would therefore
be a violation of 14 CFR 91.7(a), which
states that no person may operate a civil
aircraft unless it is in an airworthy
condition. Any individual taking such
action is subject to a civil penalty for a
violation of the Federal Aviation
Regulations.
F. Comments on the Negative Impact of
the FAA’s Actions
Request: Several commenters stated
that the AD would create confusion or
skepticism in the flying community, and
will prevent aircraft owners from
adopting new technologies promoted by
the FAA in the future. Some
commenters stated that because of the
AD people will quit flying; many others
stated aircraft owners will choose to
operate without ADS–B equipment.
These commenters requested or implied
that we withdraw the NPRM.
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FAA Response: We disagree.
Although the FAA sympathizes with
owners who became early adopters of
this technology in good faith and
unfortunately are now adversely
affected by a situation not of their
making, the potential for this action to
create skepticism and distrust of the
FAA among aircraft owners does not
negate the need to correct the identified
unsafe condition. The FAA’s failure to
take action to correct this unsafe
condition could lead to accidents,
which would also reasonably result in
skepticism and distrust of the FAA, not
only on the part of the flying
community but of the public at large.
We did not change the AD based on
these comments.
Request: A few commenters stated the
FAA created this problem by suddenly
and unilaterally changing the
operational ADS–B rules to deny TIS–B
data to aircraft broadcasting a SIL of 0.
Two of these commenters noted that
NavWorx initially submitted data to
substantiate a SIL of 3, but the FAA
refused to grant NavWorx TSO
authorization unless the units broadcast
a SIL of 0. The commenters request the
FAA provide TIS–B data to all aircraft,
regardless of SIL.
FAA Response: We disagree. The
FAA’s changes to only provide TIS–B
services to aircraft broadcasting a SIL
greater than 0 were neither sudden nor
unilateral. The changes were announced
on March 31, 2015, and became
effective in early 2016.11 However, they
were initiated several years prior, as the
result of an FAA study to determine a
low risk, cost-effective, technically
beneficial strategy for modification of
the FAA TIS–B service. During this
study, we consulted with the current
manufacturers of ADS–B systems (both
certified and uncertified) designed to
use TIS–B information, including
Accord Technologies, Dynon, FreeFlight
Systems, Garmin, Honeywell, NavWorx,
Rockwell Collins, and Trig. Like other
manufacturers, NavWorx had the
opportunity to make and obtain
approval for appropriate design changes
to its equipment so its customers could
receive TIS–B traffic after the service
change. NavWorx chose instead to only
change the SIL setting from 0 to 3 in
software without demonstrating the
existing GPS position source’s
qualification to broadcast of a SIL of 3.
Since that time, the FAA has been
requesting NavWorx submit testing data
supporting its conclusion that the SiRF
IV GPS meets the performance
11 A copy of the FAA’s announcement of its
decision to make changes to the TIS–B service is
available for review in Docket No. FAA–2016–9226.
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18:18 Jun 05, 2017
Jkt 241001
requirements to broadcast a SIL of 3.
NavWorx has not provided the FAA
with this data.
We also disagree with the contention
that NavWorx initially submitted data to
substantiate a SIL of 3. NavWorx’s TSOauthorized design for its P/N 200–0012
and P/N 200–0013 ADS–B units has
always identified the internal GPS
source for those units as an uncertified
SiRF IV GPS. The SiRF IV is not
manufactured under an FAA TSO. The
FAA approved this equipment and its
installation to transmit a SIL of 0
because that is what is required by
RTCA Document DO–282B (the
performance standard for TSO–C154c
and the NavWorx units) and AC 20–
165B.
The commenters’ request to provide
TIS–B data to all aircraft, regardless of
SIL, would not correct the unsafe
condition. We did not change the AD
based on these comments.
G. Comments Beyond the Scope of the
NPRM
Request: A few commenters expressed
disagreements with the ADS–B
mandate. One commenter stated
compliance with the rule would put
him out of business, because he did not
fly often enough to justify the cost.
Another commenter requested the
mandate not apply to aircraft operating
under VFR in certain airspace. The third
commenter stated that because of the
mandate, the FAA is unable to manage
the increase in ADS–B technology
development or deal with the market.
FAA Response: Comments about the
2020 mandate are beyond the scope of
this AD. The rules mandating ADS–B
Out usage, 14 CFR 91.225 and 91.227,
were promulgated through notice and
comment rulemaking that began with an
aviation rulemaking committee. An
NPRM was issued in 2007 (72 FR 56947,
October 5, 2007) and the comment
period was subsequently re-opened for
an additional 30 days in 2008 (73 FR
57270, October 2, 2008). The final rule
published on May 28, 2010 (75 FR
30160) and considered approximately
240 comments from air carriers,
manufacturers, associations, and
individuals. All documentation of this
rulemaking is available for review in
Docket No. FAA–2007–29305.
Request: Some commenters requested
or implied they should be given until
2025 to comply with the AD because
compliance with the ADS–B mandate is
not required for air carriers until 2025.
FAA Response: Comments about the
2020 mandate are beyond the scope of
this AD. It appears the commenters are
referring to Exemption No. 12555,
which is not a blanket 5-year extension
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for all air carriers. Exemption No. 12555
applies only to those operators who
submit a request to use it and who
comply with its conditions and
limitations. Exemption No. 12555
allows the use of current ADS–B Out
systems that are not fully compliant
with the rule until fully compliant
systems are installed on or before
January 1, 2025. Documentation
concerning Exemption No. 12555 is
available for review in Docket No. FAA–
2015–0971.
Comment: One commenter described
a safety of flight issue he encountered
with a Garmin ADS–B transponder that
he has previously reported to the FAA.
FAA Response: The comment is not
relevant to whether this AD is necessary
to correct the unsafe condition
presented by the NavWorx ADS–B units
broadcasting a SIL of 0. We did not
change the AD based on this comment.
Comment: A few commenters
expressed criticism of the FAA in
general, without requesting specific
changes to this AD.
FAA Response: The comments are not
relevant to whether this AD is necessary
to correct the unsafe condition
presented by the NavWorx ADS–B units
broadcasting a SIL of 0. We did not
change the AD based on these
comments.
FAA’s Determination
We have reviewed the relevant
information, considered the comments
received, and determined that an unsafe
condition exists and is likely to exist or
develop on other products of this same
type design and that air safety and the
public interest require adopting the AD
requirements as proposed with the
changes described previously. These
changes are consistent with the intent of
the proposals in the NPRM (81 FR
72552, October 20, 2016) and will not
increase the economic burden on any
operator nor increase the scope of the
AD.
Related Service Information
We reviewed NavWorx AFMS for
ADS600–B as installed under STC No.
SA11172SC, approved May 4, 2014;
NavWorx Installation Manual for
ADS600–B Part 23 AML STC 240–0021–
00–07, Revision 7, dated May 4, 2014;
and NavWorx STC Master Drawing List
240–0013–00, Revision 10, dated May
29, 2014. This service information
identifies the internal GPS position
source for the NavWorx Model
ADS600–B P/N 200–0012 and P/N 200–
0013 as uncertified and not compliant
with 14 CFR 91.225 and 91.227.
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Costs of Compliance
We estimate that this AD affects
approximately 800 ADS–B units
installed on various aircraft of U.S.
registry. Operators may incur the
following costs in order to comply with
this AD based on an average labor rate
of $85 per work-hour. Removing the
ADS–B unit, disabling the ADS–B unit,
or revising the software of the ADS–B
unit will take about 1 work-hour, for a
total of $85 per aircraft. Coupling the
ADS–B unit with an approved external
GPS will take about 4 work-hours for a
total of $340 per aircraft.
sradovich on DSK3GMQ082PROD with RULES
Authority for This Rulemaking
Title 49 of the United States Code
specifies the FAA’s authority to issue
rules on aviation safety. Subtitle I,
section 106, describes the authority of
the FAA Administrator. Subtitle VII:
Aviation Programs, describes in more
detail the scope of the Agency’s
authority.
We are issuing this rulemaking under
the authority described in Subtitle VII,
Part A, Subpart III, Section 44701:
‘‘General requirements.’’ Under that
section, Congress charges the FAA with
promoting safe flight of civil aircraft in
air commerce by prescribing regulations
for practices, methods, and procedures
the Administrator finds necessary for
safety in air commerce. This regulation
is within the scope of that authority
because it addresses an unsafe condition
that is likely to exist or develop on
products identified in this rulemaking
action.
Regulatory Findings
This AD will not have federalism
implications under Executive Order
13132. This AD will not have a
substantial direct effect on the States, on
the relationship between the national
government and the States, or on the
distribution of power and
responsibilities among the various
levels of government.
For the reasons discussed above, I
certify that this AD:
(1) Is not a ‘‘significant regulatory
action’’ under Executive Order 12866;
(2) Is not a ‘‘significant rule’’ under
DOT Regulatory Policies and Procedures
(44 FR 11034, February 26, 1979);
(3) Will not affect intrastate aviation
in Alaska to the extent that it justifies
making a regulatory distinction; and
(4) Will not have a significant
economic impact, positive or negative,
on a substantial number of small entities
under the criteria of the Regulatory
Flexibility Act.
We prepared an economic evaluation
of the estimated costs to comply with
this AD and placed it in the AD docket.
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List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation
safety, Incorporation by reference,
Safety.
Adoption of the Amendment
Accordingly, under the authority
delegated to me by the Administrator,
the FAA amends 14 CFR part 39 as
follows:
PART 39—AIRWORTHINESS
DIRECTIVES
1. The authority citation for part 39
continues to read as follows:
■
Authority: 49 U.S.C. 106(g), 40113, 44701.
§ 39.13
[Amended]
2. The FAA amends § 39.13 by adding
the following new airworthiness
directive (AD):
■
2017–11–11 NavWorx, Inc.: Amendment
39–18910; Docket No. FAA–2016–9226;
Directorate Identifier 2016–SW–065–AD.
(a) Applicability
This AD applies to the following NavWorx,
Inc., Automatic Dependent SurveillanceBroadcast (ADS–B) Universal Access
Transceiver units (unit) installed on aircraft
certificated in any category, including
experimental:
(1) Model ADS600–B part number (P/N)
200–0012;
(2) Model ADS600–B P/N 200–0013; and
(3) Model ADS600–EXP P/N 200–8013.
(b) Unsafe Condition
This AD defines the unsafe condition as an
ADS–B unit incorrectly broadcasting a
Source Integrity Level (SIL) of 3 instead of its
authorized SIL of 0. This condition could
result in the unit communicating unreliable
position information to Air Traffic Control
and nearby aircraft and a subsequent aircraft
collision.
(c) Effective Date
This AD becomes effective July 11, 2017.
(d) Compliance
You are responsible for performing each
action required by this AD within the
specified compliance time unless it has
already been accomplished prior to that time.
(e) Required Actions
(1) Within 6 months, comply with either
paragraph (e)(1)(i), (ii), (iii), or (iv) of this AD:
(i) Remove the ADS–B unit.
(ii) Disable and prohibit use of the ADS–
B unit as follows:
(A) Pull and secure the circuit breaker and
disconnect the internal GPS antenna
connector from the ADS–B unit and secure.
(B) Install a placard in view of the pilot
that states ‘‘USING THE ADS–B SYSTEM IS
PROHIBITED.’’
(C) Revise the Limitations section of the
Aircraft Flight Manual supplement (AFMS)
by inserting a copy of this AD or by making
pen-and-ink changes to add the following:
PO 00000
Frm 00023
Fmt 4700
Sfmt 4700
25953
‘‘USING THE ADS–B SYSTEM IS
PROHIBITED.’’
(iii) Revise the software so the ADS–B unit
broadcasts a SIL of 0.
(iv) Couple the ADS–B unit with an
approved external GPS as follows:
(A) Interface the ADS–B unit with an
Accord NexNav mini LRU GPS Receiver P/
N 21000.
(B) Revise the Limitations section of the
AFMS by inserting a copy of this AD or by
making pen-and-ink changes to add the
following: ‘‘OPERATION USING THE
INTERNAL POSITION SOURCE IS
PROHIBITED. USE OF THE ACCORD
NEXNAV MINI P/N 21000 EXTERNAL
POSITION SOURCE IS REQUIRED.’’
(2) After the effective date of this AD, do
not install an ADS–B unit Model ADS600–B
P/N 200–0012, Model ADS600–B P/N 200–
0013, or Model ADS600–EXP P/N 200–8013
on any aircraft unless you have complied
with the requirements of paragraph (e)(1)(ii),
(e)(1)(iii), or (e)(1)(iv) of this AD.
(f) Alternative Methods of Compliance
(AMOCs)
(1) The Manager, Fort Worth Aircraft
Certification Office, FAA, may approve
AMOCs for this AD. Send your proposal to:
Kyle Cobble, Aviation Safety Engineer, Fort
Worth Aircraft Certification Office, Rotorcraft
Directorate, FAA, 10101 Hillwood Pkwy, Fort
Worth, TX 76177, telephone (817) 222–5172,
email kyle.cobble@faa.gov; or Michael
Heusser, Program Manager, Continued
Operational Safety Branch, Fort Worth
Aircraft Certification Office, Rotorcraft
Directorate, 10101 Hillwood Pkwy, Fort
Worth, TX 76177, telephone (817) 222–5038,
email michael.a.heusser@faa.gov.
(2) For operations conducted under a 14
CFR part 119 operating certificate or under
14 CFR part 91, subpart K, we suggest that
you notify your principal inspector, or
lacking a principal inspector, the manager of
the local flight standards district office or
certificate holding district office before
operating any aircraft complying with this
AD through an AMOC.
(g) Additional Information
NavWorx Airplane Flight Manual
Supplement for ADS600–B as installed under
Supplemental Type Certificate (STC) No.
SA11172SC, approved May 4, 2014;
NavWorx Installation Manual for ADS600–B
Part 23 AML STC 240–0021–00–07, Revision
7, dated May 4, 2014; and NavWorx STC
Master Drawing List 240–0013–00, Revision
10, dated May 29, 2014, which are not
incorporated by reference, contain additional
information about the subject of this AD. For
service information identified in this AD,
contact NavWorx Inc.; telephone (888) 628–
9679; email: support@navworx.com or at
www.navworx.com. You may review a copy
of this information at the FAA, Office of the
Regional Counsel, Southwest Region, 10101
Hillwood Pkwy, Room 6N–321, Fort Worth,
TX 76177.
(h) Subject
Joint Aircraft Service Component (JASC)
Code: 3452, ATC Transponder System.
E:\FR\FM\06JNR1.SGM
06JNR1
25954
Federal Register / Vol. 82, No. 107 / Tuesday, June 6, 2017 / Rules and Regulations
Issued in Fort Worth, Texas, on May 30,
2017.
Lance T. Gant,
Manager, Rotorcraft Directorate, Aircraft
Certification Service.
SW., Renton, WA. For information on
the availability of this material at the
FAA, call 425–227–1221. It is also
available on the Internet at https://
www.regulations.gov by searching for
and locating Docket No. FAA–2016–
8179.
Examining the AD Docket
[FR Doc. 2017–11625 Filed 6–5–17; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2016–8179; Directorate
Identifier 2015–NM–201–AD; Amendment
39–18913; AD 2017–11–14]
RIN 2120–AA64
Airworthiness Directives; The Boeing
Company Airplanes
Federal Aviation
Administration (FAA), DOT.
ACTION: Final rule.
AGENCY:
We are superseding
Airworthiness Directive (AD) 2011–26–
03, which applied to certain The Boeing
Company Model 777–200, –200LR,
–300, and –300ER series airplanes. AD
2011–26–03 required installing Teflon
sleeving under the clamps of certain
wire bundles routed along the fuel tank
boundary structure, and cap sealing
certain penetrating fasteners of the main
and center fuel tanks. This AD requires
certain inspections for certain airplanes,
corrective actions if necessary, and
installation of Teflon sleeves under
certain wire bundle clamps. This AD
was prompted by a report indicating
that additional airplanes are affected by
the identified unsafe condition. We are
issuing this AD to address the unsafe
condition on these products.
DATES: This AD is effective July 11,
2017.
The Director of the Federal Register
approved the incorporation by reference
of a certain publication listed in this AD
as of July 11, 2017.
The Director of the Federal Register
approved the incorporation by reference
of certain other publications listed in
this AD as of January 20, 2011 (75 FR
78588, December 16, 2010).
ADDRESSES: For service information
identified in this final rule, contact
Boeing Commercial Airplanes,
Attention: Contractual & Data Services
(C&DS), 2600 Westminster Blvd., MC
110–SK57, Seal Beach, CA 90740–5600;
telephone: 562–797–1717; Internet:
https://www.myboeingfleet.com. You
may view this referenced service
information at the FAA, Transport
Airplane Directorate, 1601 Lind Avenue
sradovich on DSK3GMQ082PROD with RULES
SUMMARY:
VerDate Sep<11>2014
18:18 Jun 05, 2017
Jkt 241001
prevent arcing inside the main and
center fuel tanks in the event of a fault
current or lightning strike, which, in
combination with flammable fuel
vapors, could result in a fuel tank
explosion and consequent loss of the
airplane.
Comments
We gave the public the opportunity to
participate in developing this AD. The
following presents the comments
received on the NPRM and the FAA’s
response to each comment.
You may examine the AD docket on
the Internet at https://
www.regulations.gov by searching for
and locating Docket No. FAA–2016–
8179; or in person at the Docket
Management Facility between 9 a.m.
and 5 p.m., Monday through Friday,
except Federal holidays. The AD docket
contains this AD, the regulatory
evaluation, any comments received, and
other information. The address for the
Docket Office (phone: 800–647–5527) is
Docket Management Facility, U.S.
Department of Transportation, Docket
Operations, M–30, West Building
Ground Floor, Room W12–140, 1200
New Jersey Avenue SE., Washington,
DC 20590.
FOR FURTHER INFORMATION CONTACT: Tak
Kobayashi, Aerospace Engineer,
Propulsion Branch, ANM–140S, Seattle
Aircraft Certification Office (ACO),
FAA, 1601 Lind Avenue SW., Renton,
WA 98057–3356; phone: 425–917–6499;
fax: 425–917–6590; email:
takahisa.kobayashi@faa.gov.
SUPPLEMENTARY INFORMATION:
Discussion
We issued a notice of proposed
rulemaking (NPRM) to amend 14 CFR
part 39 to supersede AD 2011–26–03,
Amendment 39–16893 (76 FR 78138,
December 16, 2011) (‘‘AD 2011–26–
03’’). AD 2011–26–03 applied to certain
The Boeing Company Model 777–200,
–200LR, –300, and –300ER series
airplanes. The NPRM published in the
Federal Register on July 20, 2016 (81 FR
47084). The NPRM was prompted by a
report indicating that additional
airplanes are affected by the identified
unsafe condition. The NPRM proposed
to continue to require installing Teflon
sleeving under the clamps of certain
wire bundles routed along the fuel tank
boundary structure, and cap sealing
certain penetrating fasteners of the main
and center fuel tanks. The NPRM also
proposed to revise the applicability by
adding The Boeing Company Model
777F series airplanes. The NPRM also
proposed to add, for certain airplanes,
detailed inspections of certain wire
bundle clamps, certain Teflon sleeves,
and certain fasteners; corrective actions
if necessary; and installation of Teflon
sleeves under certain wire bundle
clamps. We are issuing this AD to
PO 00000
Frm 00024
Fmt 4700
Sfmt 4700
Request To Withdraw the NPRM
Boeing requested that we withdraw
the NPRM. The commenter stated that
the actions proposed by the NPRM are
no longer necessary, since the unsafe
condition is adequately addressed by
repetitive inspections required by the
electrical wiring interconnection system
(EWIS) enhanced zonal analysis
procedure (EZAP) inspection program
required by 14 CFR part 26. The
commenter pointed out that, since the
time this issue was determined to be a
safety issue, the exposure assumed
under the safety assessment has
changed due to the inspection program.
The commenter stated that the safety
concern was that the failure of multiple
protective design features for wiring
installations could be a single cascading
failure since the exposure was the life
of the airplane. The commenter stated
that since the implementation of the
EWIS EZAP inspections, where the
interval is now 6 years, this is no longer
considered to be a single failure as the
exposure has been reduced to where the
wiring and installation is not expected
to fail in this inspection interval and
any potential wear would be detected
and would be repaired or removed and
replaced in accordance with
maintenance activities.
We disagree to withdraw the NPRM.
The EWIS EZAP repetitive inspection
program is implemented by FAA
operating rules (14 CFR 121.1111 or 14
CFR 129.111), which are applicable only
to operators that are required to comply
with those operating rules. The FAA is
obligated to advise foreign airworthiness
authorities of unsafe conditions
identified in products manufactured in
the United States, including Boeing
airplanes, in accordance with bilateral
airworthiness agreements with countries
around the world. The issuance of ADs
is the means by which the FAA satisfies
this obligation. Even if the FAA agreed
that the actions required by 14 CFR
121.1111 and 14 CFR 129.111
adequately addressed the unsafe
condition, the FAA would still issue
this AD to address airplanes that may
E:\FR\FM\06JNR1.SGM
06JNR1
Agencies
[Federal Register Volume 82, Number 107 (Tuesday, June 6, 2017)]
[Rules and Regulations]
[Pages 25946-25954]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-11625]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2016-9226; Directorate Identifier 2016-SW-065-AD;
Amendment 39-18910; AD 2017-11-11]
RIN 2120-AA64
Airworthiness Directives; NavWorx, Inc. Automatic Dependent
Surveillance Broadcast Universal Access Transceiver Units
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: We are adopting a new airworthiness directive (AD) for
NavWorx, Inc. (NavWorx), Automatic Dependent Surveillance Broadcast
(ADS-B) Universal Access Transceiver Units (unit). This AD requires
removing, disabling, or modifying the ADS-B unit. This AD was prompted
by a design change that results in the unit communicating unreliable
position information. The actions in this AD are intended to address an
unsafe condition on these products.
DATES: This AD is effective July 11, 2017.
Examining the AD Docket
You may examine the AD docket on the Internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2016-
9226; or in person at the Docket Operations Office between 9 a.m. and 5
p.m., Monday through Friday, except Federal holidays. The AD docket
contains this AD, Supplemental Type Certificate (STC) No. SA11172SC,
the economic evaluation, any comments received, and other information.
The street address for the Docket Operations Office (phone: 800-647-
5527) is U.S. Department of Transportation, Docket Operations Office,
M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue
SE., Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Kyle Cobble, Aviation Safety Engineer,
Fort Worth Aircraft Certification Office (ACO), Rotorcraft Directorate,
FAA, 10101 Hillwood Pkwy, Fort Worth, TX 76177, telephone (817) 222-
5172, email kyle.cobble@faa.gov; or Michael Heusser, Program Manager,
Continued Operational Safety Branch, Fort Worth ACO, Rotorcraft
Directorate, FAA, 10101 Hillwood Pkwy, Fort Worth, TX 76177, telephone
(817) 222-5038, email michael.a.heusser@faa.gov.
SUPPLEMENTARY INFORMATION:
Discussion
On October 20, 2016, at 81 FR 72552, the Federal Register published
our notice of proposed rulemaking (NPRM), which proposed to amend 14
CFR part 39 by adding an AD that would apply to NavWorx ADS-B Model
ADS600-B units, part number (P/N) 200-0012 and P/N 200-0013, and Model
ADS600-EXP units, P/N 200-8013. The NPRM proposed to require removing
the ADS-B unit before further flight and proposed to prohibit
installing the affected ADS-B unit on any aircraft. The NPRM was
prompted by a design change that resulted in the ADS-B units
broadcasting a Source Integrity Level (SIL) of 3 instead of 0. A
broadcast of SIL 0 is required because of the uncertified Global
Positioning System (GPS) source included in the unit. The proposed
actions were intended to prevent an ADS-B unit from communicating
unreliable position information to Air Traffic Control (ATC) and nearby
aircraft and a subsequent aircraft collision.
Comments
We gave the public the opportunity to participate in developing
this AD. We received approximately 200 comments, mostly from
individuals but also from NavWorx and organizations such as the
Aircraft Owners and Pilots Association (AOPA), the Experimental
Aircraft Association (EAA), and the Aircraft Electronics Association
(AEA). The following presents the comments received on the NPRM and the
FAA's response to each comment.
A. Support for the NPRM
Five individual commenters supported the NPRM.
B. Comments Regarding the FAA's Justification of the Unsafe Condition
Several commenters, including AOPA, requested that the FAA provide
more information about the events that prompted this AD and the
technical aspects surrounding the unsafe condition. We agree.
Request: AOPA requested the FAA clarify whether the internal
position source in the ADS-B units meets the performance requirements
in Appendix B to Advisory Circular (AC) 20-165B. In support of this
request, AOPA stated the FAA's contention that NavWorx did not present
any data substantiating its SIL change is contrary to NavWorx's public
statements that its testing verified the position source met the
integrity levels required by the regulations. Similarly, NavWorx
commented on the AD and maintained it has provided the FAA with data
demonstrating the internal GPS met the requirements to transmit a SIL
of 3.
FAA Response: NavWorx has not demonstrated to the FAA that the
internal position source meets the performance requirements in Appendix
B to AC 20-165B \1\ for a SIL of 3. The design specifications for
NavWorx's P/N 200-0012 and 200-0013 ADS-B units identify the internal
GPS source for those units as an uncertified SiRF IV GPS. The SiRF IV
is a commercial grade chipset not manufactured under an FAA Technical
Standard Order (TSO). AC 20-165B requires the SIL be set at 0 when the
ADS-B is integrated with an uncertified GPS source. When NavWorx
submitted its software upgrade changing the SIL value from 0 to 3, no
hardware design changes associated with the SIL value change were made
to the ADS-B units and no testing data substantiating that SIL change
was provided to the FAA. The only justification NavWorx cited for the
software change was the FAA's termination of Traffic Information
Service--Broadcast (TIS-B) services to aircraft broadcasting ADS-B with
a SIL of 0. This data is available for review in Docket No. FAA-2016-
9226.
---------------------------------------------------------------------------
\1\ https://rgl.faa.gov/Regulatory_and_Guidance_Library/.
---------------------------------------------------------------------------
Request: AOPA requested the FAA clarify its meaning of
``uncertified GPS source'' since NavWorx has design approval through
STC No. SA11172SC to install the ADS-B unit with the internal GPS on
type-certificated aircraft, and since a compliant position source does
not need to meet a specific TSO to meet the requirements set forth in
Appendix B of AC 20-165B.
Some commenters requested the FAA explain why it approved NavWorx's
ADS-B units at all if the internal, uncertified GPS source is
objectionable. Many commenters stated the NavWorx ADS-B units meet the
performance and accuracy/integrity standards of TSO C-154c; others
noted that NavWorx has stated its testing showed the units meet the
requirements to broadcast a SIL of
[[Page 25947]]
3. Several commenters disagreed with the AD because the GPS source is
not required to be certified separately from the ADS-B unit.
FAA Response: The commenters, including NavWorx, are correct that
the position source only needs to meet certain performance requirements
and does not need to be certified under a TSO. However, despite
NavWorx's statements and comments to the contrary, NavWorx has
presented no data to the FAA--test plans and test results--that
demonstrate the affected units with the internal SiRF IV GPS meet the
performance standards to transmit a SIL of 3. Similarly, NavWorx has
never demonstrated to the FAA that the affected units meet the 14 CFR
Sec. 91.227 requirements to broadcast a SIL of 3 when using the
internal SiRF IV GPS.
NavWorx's TSO-C154c authorization and STC were approved based on
the P/N 200-0012 and 200-0013 units broadcasting a SIL of 0 when using
the internal uncertified GPS position source. NavWorx documented this
as a limitation in the Aircraft Flight Manual Supplement (AFMS) for
NavWorx's STC for ADS600-B installations. Section 2.6 of the AFMS,
titled ``Uncertified GPS Receiver (P/N 200-0012 and 200-0013),''
states:
The ADS600-B has an internal uncertified GPS WAAS receiver which
does not meet the 14 CFR 91 FAA-2007-29305 rule for certified GPS
position source. If the ADS600-B is configured to use the internal
uncertified GPS as the position source the ADS-B messages
transmitted by the unit reports: A Source Integrity Limit (SIL) of 0
indicating that the GPS position source does not meet the 14 CFR 91
FAA-2007-29305 rule.
While 14 CFR Sec. 91.227 requires a SIL of 3, TSO-C154c (the TSO
under which the affected units are produced) does not. Thus, when the
affected units broadcast a SIL of 0, they are TSO-compliant. Until the
performance requirements of 14 CFR Sec. 91.227 become effective on
January 1, 2020, the FAA does not find the internal uncertified GPS
source objectionable, as long as the ADS-B unit is correctly
broadcasting a SIL of 0. It is NavWorx's change of the SIL setting in
these units to 3, without any qualification of the internal uncertified
GPS position source to support broadcast of SIL 3, that the FAA finds
unacceptable. In this condition, the units are transmitting to ATC and
to nearby aircraft that they have 14 CFR Sec. 91.227-compliant
position source integrity, when their position source integrity is
actually not compliant with that rule, or is unknown. We discuss the
safety effects of this condition in greater detail below.
Request: AOPA requested the FAA further explain its finding that
the affected units create an unsafe condition. Many commenters
questioned the FAA's determination that the units present an unsafe
condition, and asked whether any units have actually caused a collision
or safety incident. Many other commenters stated they have been
operating with the NavWorx unit and find it accurate and reliable.
Several commenters stated the NavWorx units increase safety and noted
that the National Transportation Safety Board has recommended ADS-B
units to the flying public.
FAA Response: The FAA's safety concern is primarily that of
integrity, and not necessarily accuracy, with respect to the NavWorx
ADS-B unit's performance requirements. Accuracy refers to the
probability of the unit's true position in relation to its reported
position.\2\ Integrity refers to the trust that can be placed in the
correctness of the information provided by the unit and is specified by
a SIL value. The SIL value is set based on design data from the GPS
position source manufacturer and reflects the probability that the
position source will provide incorrect data without providing an alert.
This depends on whether the GPS has fault detection and exclusion,
where the equipment will detect a faulty satellite and exclude it from
the navigational calculations. If the GPS does not have fault detection
and exclusion, the probability that the position source will provide
incorrect data increases. Commercial position sources, such as the SiRF
IV GPS used in the NavWorx P/N 200-0012, 200-0013, and 200-8013 units,
do not have fault detection and exclusion capabilities. This is
significant in the event a GPS satellite signal fails or a GPS
``signal-in-space error'' occurs.
---------------------------------------------------------------------------
\2\ Accuracy of an aircraft's reported position is specified as
Navigation Accuracy Category for Position, or NACP. A
unit that complies with 14 CFR 91.227 has a NACP
corresponding to an accuracy of better than 0.05 nautical miles. The
NavWorx units' compliance with the 14 CFR 91.227 NACP (accuracy)
performance requirements is not the concern that prompted this AD.
---------------------------------------------------------------------------
The unsafe condition relates to the potential for the NavWorx unit
to incorrectly report its own position to other aircraft and to ATC, by
0.2 nautical miles (NM) or more, without providing an alert.\3\ It may
also result in ATC providing incorrect and inappropriate separation
instructions or traffic advisories to other aircraft for avoidance of
the ADS600-B-equipped aircraft, based on the erroneous position being
reported by the ADS600-B. In this situation, the pilot of the ADS600-B-
equipped aircraft would be unaware that his or her aircraft's ADS-B Out
unit is broadcasting an erroneous position (possibly in excess of 0.2
NM), since the ADS600-B would not be providing an alert for this
condition. Depending on operating conditions, these effects may occur
in instrument meteorological conditions where see-and-avoid is not
possible. In view of these factors, this condition poses an
unacceptable hazard to other users of the National Airspace System
(NAS).
---------------------------------------------------------------------------
\3\ 0.2 NM is the minimum integrity containment radius around
the aircraft's reported position required by 14 CFR Sec. 91.227
(c)(1)(iii).
---------------------------------------------------------------------------
Although there have been no reported cases of a collision or safety
incident resulting from an incorrect transmission by a NavWorx ADS-B
unit to date, the potential for the unsafe condition exists as long as
the units mislead ATC and nearby aircraft by broadcasting a SIL of 3
that they have not been shown to meet. This AD action addresses that
potential unsafe condition.
The fact that commenters have made flight tests with satisfactory
ADS-B performance monitor reports from the FAA, or that commenters'
individual units have been operating successfully, does not negate the
existence of an unsafe condition. Flight tests with the ADS-B
performance monitor are designed primarily to show that the ADS-B
equipment in an individual aircraft performs correctly as installed.
These tests are of relatively short duration and occur in fault-free
conditions. They are not engineering tests designed to evaluate the
unit's ability to handle GPS signal-in-space errors and cannot be used
to draw inferences about the unit's position source integrity.
Although the FAA recognizes the benefits of ADS-B equipage and
understands that the NavWorx units may work a large percentage of the
time for an individual user, the FAA must consider the effect on the
entire NAS. Since failure is based on a statistical probability, the
odds that a unit will have a failure increase as more units are
introduced into the NAS and operate for a longer period of time. The
probability of a failure also increases when there is a GPS satellite
malfunction, which could affect many aircraft since the information is
used by ATC and ADS-B In equipped aircraft for separation. Therefore,
despite any benefit to individual owners when the unit works without
failure, the FAA has determined that an unsafe condition with the
NavWorx units exists and requires corrective action because of the
hazard they pose to other users of the NAS.
[[Page 25948]]
Request: AOPA requested the FAA produce for public inspection the
Small Airplane Risk Analysis (SARA) documentation.
FAA Response: As part of our risk assessment, we initially
performed a SARA. However, the SARA assumes failure on one airplane.
The issue with the NavWorx ADS-B units poses risk to the NAS.
Specifically, a malfunction at the satellite level could result in
transmission of hazardously misleading position information from the
ADS600-B-equipped aircraft to ATC and to other aircraft. It could also
cause such malfunctions in all aircraft with the affected ADS-B units
installed that are using the signal from the malfunctioning satellite
to determine their position. Thus, we determined the SARA results
provided questionable value, and that it was more appropriate to use
the safety risk methodology from the ADS-B program, as documented in
Safety Risk Management Document (SRMD) Critical Services: Standard
Terminal Automation Replacement System (STARS) with Automatic Dependent
Surveillance Broadcast (ADS-B) Only Addendum, SBS-036C, Revision 1,
dated August 26, 2014 (SBS-036C).
In SBS-036C, we analyze safety risk as a composite of two factors:
The potential ``severity'' or worst possible consequence or outcome of
an adverse effect that is assumed to occur, and the ``likelihood'' of
occurrence for that specific adverse event. We assess both factors
independently and then enter each as separate inputs into a risk
matrix, which yields an overall level of risk for the event as Low
(acceptable), Medium (acceptable with mitigation), or High
(unacceptable). The corrective action, if any, is driven by the
assessed overall risk. Figure ES-1 of SBS-036C contains the risk matrix
the FAA used for this AD.
The FAA considered an undetected position error event of 0.2 NM or
more for a single aircraft as a ``Position error outside containment
bound for single aircraft undetected by airborne equipment/ground
automation'' hazard, which has a classified severity of ``hazardous''
per Table ES-1 and Appendix B of SBS-036C. Hazardous is defined in AC
23.1309-1E, System Safety Analysis and Assessment for Part 23
Airplanes,\4\ as resulting in a large reduction in safety margins,
physical distress or higher workload, or serious or fatal injury to an
occupant other than the flight crew. A large position error (0.2 NM or
more) may lead to loss of separation, increased ATC workload, a
reduction in safety margins, and a near midair collision. These are
unsafe conditions that warrant a ``hazardous'' severity level for risk
assessment purposes.
---------------------------------------------------------------------------
\4\ https://rgl.faa.gov/Regulatory_and_Guidance_Library/.
---------------------------------------------------------------------------
From Table ES-1 of SBS-036C, the likelihood of this failure for a
properly functioning system was assessed as extremely improbable.
Figure ES-1 in SBS-036C is a risk matrix that yields an overall risk
based on the severity classification and the assessed likelihood of
occurrence. A severity classification of ``hazardous'' and an assessed
likelihood of ``extremely improbable'' yields an overall risk of
``Low,'' which is an acceptable risk.
However, the likelihood assessment of ``extremely improbable'' in
Table ES-1 is based on the aircraft's GPS receiver having either fault
detection or fault detection and exclusion, which is required in order
to meet the ADS-B Out position integrity requirements of 14 CFR 91.227.
A GPS receiver with fault detection detects a faulty satellite signal
and provides an alert of the fault. If the GPS receiver has fault
detection and exclusion, it additionally excludes the faulty satellite
signal from the position computation. Because the GPS position source
in the NavWorx ADS600-B units has no demonstrated fault detection or
exclusion features, the FAA determined the appropriate likelihood
should be based on the GPS constellation fault rate of
10-\4\ per hour (that is, a probability of 0.0001
occurrences per flight hour). As a result, the FAA elevated the risk of
the hazard and assessed a likelihood of ``remote.'' \5\ Using the
severity classification of ``hazardous'' and an assessed likelihood of
``remote'' yields an overall risk of ``High'' in Figure ES-1. This is
an unacceptable risk.
---------------------------------------------------------------------------
\5\ Although the CARB assessed a likelihood of ``remote,''
Figure 2 of AC 23.1309-1E assesses a likelihood between ``remote''
and ``probable,'' depending on the class of aircraft, for a
probability of 10\-4\. Either likelihood classification would yield
a High overall risk on the Figure ES-1 risk matrix.
---------------------------------------------------------------------------
These determinations are documented in the meeting minutes from the
FAA's Corrective Action Review Board (CARB) held on September 19, 2016.
In accordance with FAA Order 8110.107A, Monitor Safety/Analyze Data,
the CARB considered this safety issue on that date and determined that
an unsafe condition existed with the units. This documentation is
available for review in Docket No. FAA-2016-9226.
Comment: A few commenters, including NavWorx, noted the FAA
approved software revisions 4.0.7, 4.0.8, and 4.0.9, which included the
software changes for the units to broadcast a SIL of 3.
FAA Response: The commenters are correct that the FAA approved
NavWorx's software changes identified as 4.0.7, 4.0.8, and 4.0.9.
However, none of these changes identified on NavWorx's submittals
affected the SIL value or referenced the SIL value change in 4.0.6. The
FAA's approvals did not alter the FAA's previous written statements to
NavWorx advising the equipment must report a SIL of 0 to remain
compliant with TSO-C154c. This documentation is available for review in
Docket No. FAA-2016-9226.
C. Requests To Allow Alternative Actions
Request: Many commenters, including AOPA, requested that, since the
internal GPS is the issue with the NavWorx unit, the AD allow the ADS-B
units to use an external GPS position source or, similarly, that the AD
not apply to units using an external GPS position source.
FAA Response: We agree. The only external GPS position source
approved by the FAA for interface with the ADS600-B is the Accord
NexNav mini LRU GPS Receiver P/N 21000 (Accord external GPS).\6\ We
revised the AD to allow interfacing the ADS-B unit with an Accord
external GPS as an optional corrective action. For operators who wish
to interface with other external position sources, under the provisions
of paragraph (f) of this AD, we will consider requests for approval of
an Alternative Method of Compliance (AMOC) if sufficient data is
submitted to substantiate that the unit would provide an acceptable
level of safety.
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\6\ Some commenters stated or implied that other external GPS
sources, such as the Garmin 530W, the Garmin GNS 430W, the Garmin
GNS 480, and the Garmin GTN 650, are approved for installation in
the ADS600-B. Contrary to any documentation these commenters may
have from NavWorx, the only FAA-approved external GPS source is the
Accord NexNav mini P/N 21000. Documentation of this is available for
review in Docket No. FAA-2016-9226.
---------------------------------------------------------------------------
Request: Several commenters, including AEA, requested the AD allow
disabling the unit rather than removing it.
FAA Response: We agree. We revised the AD to allow disabling the
unit as an optional corrective action.
Request: Several commenters, including AOPA, requested the AD allow
changing the SIL from 3 to 0 as an alternative to removing the unit.
FAA Response: We agree. We did not include this option in the NPRM
because NavWorx has stated it will not provide its customers with
software to change the SIL to 0. However, we revised the AD to allow
changing the
[[Page 25949]]
SIL to 0 as an alternative to removing the unit in the event such
software becomes available and is approved by the FAA.
Request: One commenter requested that the AD not apply to units
with software versions prior to 4.0.6, because these units broadcast a
SIL of 0 and thus are not subject to the unsafe condition.
FAA Response: We agree. We considered excluding units with software
prior to version 4.0.6 when we issued the NPRM. We did not exclude them
because our understanding of the units is that there is no
recordkeeping, marking, or indication from the unit itself that allows
an operator to identify the current software version. However, changes
to the AD in response to other comments render this exclusion
unnecessary.
Request: AOPA requested that we allow the units to remain in
service if NavWorx upgrades the internal position source with a
position source that meets the requirements of Appendix B to AC 20-
165B. Similarly, several commenters requested that we allow NavWorx to
re-certify the unit.
FAA Response: We agree. Should NavWorx upgrade its internal
position source with a position source that meets the performance
requirements of Appendix B to AC 20-165B, or demonstrate that the
internal SiRF IV GPS meets those requirements, under the provisions of
paragraph (f) of this AD, we will consider requests for approval of an
AMOC.
Request: Several commenters requested that we allow more time for
compliance. Two of those commenters requested that we delay compliance
until 2020, when the ADS-B operational rules become effective.
FAA Response: We agree with extending the compliance time. We
determined that safety will be maintained if the corrective actions are
implemented within six months of the effective date of the AD, and we
revised the AD accordingly.
We disagree with delaying compliance until 2020. The FAA's ADS-B
ground station network is already operational and in use by ATC
nationwide, and ADS-B In is also widely used in general aviation
aircraft for traffic awareness. Therefore, the fact that ADS-B Out will
not be required equipment until 2020 does not negate the unsafe
condition that exists from those units currently operating in the NAS.
Request: Many commenters requested that the FAA withdraw the NPRM
and instead work with NavWorx to address the unsafe condition. Some
commenters inferred a failure by the FAA in this regard because it
appeared it took the FAA six months to respond to NavWorx's design
change notification. A few commenters expressed disappointment and
outrage at the FAA's handling of the certification process with NavWorx
and requested we constructively and immediately resolve this situation.
FAA Response: We agree it is desirable to work with manufacturers
to resolve differences of opinion regarding product compliance and
correct identified safety concerns. The FAA made numerous efforts, in a
variety of forms and over a considerable period of time, to resolve
this situation with NavWorx. Those efforts were unsuccessful.
After receiving NavWorx's design change, the FAA advised NavWorx
that it could not manufacture the units as TSO C-154c units because
NavWorx had not provided acceptable data to substantiate modifying the
SIL value of the internal SiRF IV GPS to 3. Initially, NavWorx agreed
to return the SIL to 0 and requested 60 days to effect this change.
Instead, over two months later, NavWorx informed the FAA that it would
not be returning the SIL value to 0 after all. The FAA continued to
advise NavWorx, both verbally and in writing, that the SIL change
rendered the units non-compliant with the TSO. The FAA also continued
to request that NavWorx voluntarily return the SIL to 0, but NavWorx
refused. The FAA met with NavWorx and explained the means of compliance
in our existing guidance for certifying the SiRF IV GPS to broadcast a
SIL of 3, as well as the process for submitting an alternate or
equivalent means of compliance for approval. While NavWorx indicated
its desire to initiate one of those processes, it did not. Instead,
NavWorx continued to sell and ship the part-numbered 200-0012 and 200-
0013 units with the unapproved design change, and continued to furnish
product software upgrades through its Web site to existing owners that
contained the unapproved design change. When the FAA repeatedly
requested to conduct a routine inspection of NavWorx's facility, in
part to review NavWorx's units and data supporting its design change,
NavWorx refused.
After determining the situation created by NavWorx resulted in an
unsafe condition, and without NavWorx's cooperation to correct the
unsafe condition, the FAA found it necessary to issue an AD.
Documentation of these events is available for review in Docket No.
FAA-2016-9226.
Request: One commenter requested the FAA allow a temporary,
alternative solution in which operators would periodically validate the
units by flight test.
FAA Response: We disagree. Validation flight tests are not
engineering tests and are not designed to evaluate the unit's position
source integrity. The commenter's requested method of compliance would
not correct the unsafe condition.
Request: One commenter requested we exclude ADS-B units that are
already installed from the requirements of the AD.
FAA Response: We disagree. The FAA has determined an unsafe
condition exists on the affected ADS-B units and that removal or
correction of the units is required.
Request: Two commenters request the AD not apply to aircraft
operating under visual flight rules (VFR).
FAA Response: We disagree. The FAA has determined that an unsafe
condition with the NavWorx units exists and requires corrective action
because of the hazard they pose to other users of the NAS. The NavWorx
unit broadcasting a SIL of 3, when it is only authorized to broadcast a
SIL of 0, has the potential to incorrectly report its own position to
other aircraft and to ATC by 0.2 NM or more, without providing an
alert. Even in visual meteorological conditions, this could result in
the pilot of another aircraft visually searching the wrong sector of
sky for the incorrectly reporting ADS600-B-equipped aircraft or
incorrectly assessing the ADS600-B-equipped aircraft as not being a
collision threat, based on the depicted relative position of the
ADS600-B aircraft on its ADS-B In traffic display.
Request: EAA and two individual commenters requested the AD not
apply to experimental or light sport aircraft, since they are not
regulated in the same manner as type-certificated aircraft. EAA states
the FAA should address any valid airworthiness concerns with parts
intended for experimental aircraft through a Special Airworthiness
Information Bulletin (SAIB) or safety alert for operators (SAFO). Two
commenters requested the AD apply to experimental aircraft, because
those aircraft operate in the same airspace as type-certificated
aircraft and should use equipment with the same integrity. A few
commenters, including AOPA, requested we clarify whether the AD applies
to experimental aircraft.
FAA Response: We agree to clarify this issue. We confirm that the
AD applies to all aircraft, including experimental, and we revised the
AD to clarify the applicability. We made this
[[Page 25950]]
AD applicable to the ADS600-EXP P/N 200-8013 units because the design
of the Model ADS600-EXP P/N 200-8013 is substantially identical to the
Model ADS600-B P/N 200-0012 and 200-0013, specifically with regard to
the internal GPS and the SIL setting. While some commenters are correct
that the FAA has chosen to minimize regulations on experimental
aircraft because of the level of the safety risk, these risks normally
apply to the individual airplane and do not affect the overall NAS. The
safety risks defined in this AD extend beyond one aircraft and could
affect many other aircraft as well as ATC. Therefore, we find it
necessary to include experimental aircraft in the AD's applicability.
We do not agree that an SAIB or SAFO would be an appropriate
solution. These documents contain information and recommended actions
that are voluntary and not regulatory. Moreover, an SAIB is issued only
for airworthiness concerns that do not rise to the level of an unsafe
condition.
The mission of the FAA is aviation safety. ADs are used by the FAA
to correct known safety defects. It would be contrary to the intent of
the FAA's mission and statutory authority to exclude certain aircraft
when we have determined that a part installed on those aircraft has a
safety problem.
D. Comments Regarding Costs of Compliance With This AD
Request: Many commenters stated that the cost to comply with this
AD is underestimated or inaccurate and requested the FAA revise its
cost estimate. These commenters stated the cost should include the cost
to replace the unit with a new ADS-B unit and costs associated with
loss of utility; should increase the number of labor hours to account
for indirect costs such as removal and reinstallation of associated
equipment, research, and paperwork; and should increase the labor rate.
FAA Response: We disagree. The cost analysis in AD rulemaking
actions typically includes only the costs associated with complying
with the AD. In this AD, the only required action is the removal of the
unit, the deactivation of the unit, the coupling of the unit with an
approved external GPS source, or the upgrading of the software in the
unit to broadcast a SIL of 0. These actions are estimated to take 1
work-hour each, except for coupling the unit with an approved external
GPS source, which is estimated to take about 4 work-hours. The costs of
associated required actions such as installing a placard or revising
the flight manual are nominal. ADS-B Out equipment is not required for
operation until January 1, 2020, and is only required for operation in
certain specified airspace after that date. Individual operators are in
the best position to determine whether they will need to install this
equipment for the airspace they intend to operate in. Therefore,
replacement of the unit is not necessary to comply with this AD.
The labor rate of $85 per hour is provided by the FAA Office of
Aviation Policy and Plans for the FAA to use when estimating the labor
costs of complying with AD requirements.
Request: Several commenters requested the FAA revise its
determination that the AD is not a significant regulatory action. One
commenter requested the FAA analyze the costs of the AD under the
Regulatory Flexibility Act.
FAA Response: We disagree. An AD is economically significant when
the cost may have an annual effect on the economy of $100 million or
more.\7\ Even if we were to include labor for indirect costs and the
cost of replacing the unit with a new unit in our estimate, at an
estimated cost of $10,000 per aircraft and $8 million for the U.S.
fleet over the next three years, the AD would not rise to level of
economically significant. In addition, ADs correct identified unsafe
conditions, rather than raise an already adequate level of safety, and
cannot be assessed in terms of benefits balancing costs, as would be
the case for rulemaking that amends airworthiness standards.
---------------------------------------------------------------------------
\7\ A ``significant regulatory action'' is defined in Executive
Order 12866 (58 FR 51735, October 4, 1993).
---------------------------------------------------------------------------
The Regulatory Flexibility Act of 1980 (Pub. L. 96-354) (RFA)
establishes as a principle of regulatory issuance that agencies shall
endeavor, consistent with the objective of the rule and of applicable
statutes, to fit regulatory and informational requirements to the scale
of the businesses, organizations, and governmental jurisdictions
subject to regulation. To achieve that principle, the RFA requires
agencies to solicit and consider flexible regulatory proposals and to
explain the rationale for their actions. The RFA covers a wide-range of
small entities, including small businesses, not-for-profit
organizations, and small governmental jurisdictions.
Agencies must perform a review to determine whether a proposed or
final rule will have a significant economic impact on a substantial
number of small entities. If the agency determines that it will, the
agency must prepare a regulatory flexibility analysis as described in
the RFA.
However, if an agency determines that a proposed or final rule is
not expected to have a significant economic impact on a substantial
number of small entities, section 605(b) of the RFA provides that the
head of the agency may so certify and a regulatory flexibility analysis
is not required. The FAA did make such a determination for this AD. The
basis for this determination is now discussed.
The FAA uses the Small Business Association (SBA) criteria for
determining whether an affected entity is small. For aircraft
manufacturers, aviation operators, and any business using an aircraft,
the SBA criterion is 1,500 or fewer employees.
NavWorx is a small entity, and this AD could have an adverse impact
on its business interests. Besides NavWorx, the largest number of
affected small entities would most likely be operators of ADS600-B-
equipped aircraft. Based on the estimated number of units in service,
and assuming each unit is owned by a different small entity, the
largest number of small entities affected is 800.
The FAA estimates that there is a total population of 210,000
general aviation and air taxi aircraft in the United States.\8\ Of
these, approximately 70,300 (33.5%) are flown primarily for some type
of business or commercial use and thus are potentially operated by a
small entity. Aircraft flown primarily for personal use would not be
operated by a small entity as defined by the SBA.
---------------------------------------------------------------------------
\8\ Based on the FAA General Aviation and Air Taxi Activity
Survey for calendar year 2015 (the most recent year of data
available), table 1.2, General Aviation and Air Taxi Number of
Active Aircraft by Primary Use. https://www.faa.gov/data_research/aviation_data_statistics/general_aviation/CY2015/media/2015_GA_Survey_Chapter_1_Tables_16SEP2016V2.xlsx.
---------------------------------------------------------------------------
The FAA assumed all 70,300 commercial use aircraft are operated by
small entities and that each small entity operates an average of 6
aircraft,\9\ which yields an estimated number of 11,700 small entities.
We also assumed that of the 800 affected units, 33.5% (270) are used in
commercial operations.\10\ This
[[Page 25951]]
equates to a maximum of 2.3% (270/11,700) of small entities affected by
this rule. This is not a substantial number of small entities under the
RFA.
---------------------------------------------------------------------------
\9\ We based this assumption on the sanction guidance in
Appendix B of FAA Order 2150.3B, FAA Compliance and Enforcement
Program, which classifies air carriers and operators by operating
revenue, pilots employed, and aircraft operated for purposes of
determining civil penalty amounts. https://rgl.faa.gov/Regulatory_and_Guidance_Library/.
\10\ This assumption in particular is grossly high. First, some
of the affected units are installed on experimental aircraft, which
are prohibited from commercial operations and therefore could not be
used by a small entity under the RFA. Second, of the approximately
200 comments we received on the NPRM, only six commenters (NavWorx,
a charitable aircraft operator, and four avionics installation
businesses) could be presumed to be commercial entities. The
remaining comments were submitted by individuals.
---------------------------------------------------------------------------
Request: A few commenters requested or implied the FAA fund the
costs of the AD.
FAA Response: We disagree. The FAA, as a federal agency, is
responsible for all directives, policies, and mandates issued under its
authority. Although we have determined that an unsafe condition exists
with the design change to the ADS-B unit, the manufacturer is
responsible for the design change. Additionally, the FAA's budget does
not include allocations to cover AD costs incurred in modifying
privately-owned equipment.
E. Comments to the FAA's Rulemaking Process
Request: Several commenters questioned the FAA's motive in
proposing the AD. Some believed that the FAA is colluding with other
ADS-B manufacturers or industry organizations. Others suggested the FAA
is unfairly targeting NavWorx and would not be taking this action if it
involved a larger manufacturer. We interpret these comments as
requesting we withdraw the NPRM.
FAA Response: We disagree. The FAA has not communicated with any
other ADS-B product manufacturer or industry organization regarding the
compliance or safety of NavWorx products. In issuing this AD, we
followed established policy and procedures, including the public notice
and comment procedures of the Administrative Procedures Act, as well as
the DOT's ex parte policy, which can be found in Appendix 1 to 14 CFR
part 11. We placed all ex parte comments in the rulemaking docket and
considered all comments we received.
We also disagree that we are unfairly targeting NavWorx. We have
determined an unsafe condition exists on a NavWorx product and we are
requiring corrective action accordingly. If the FAA identifies similar
problems and determines that an unsafe condition exists on other ADS-B
products, whether manufactured by NavWorx or other companies, we would
take appropriate action to correct the unsafe condition.
Request: An individual commenter questioned whether we intended to
issue an AD against ADS-B transponders manufactured by Trig or Dynon.
According to the commenter, the Trig transponder allows the installer
to manually set the SIL value, and the commenter claims installers will
improperly set the SIL at 3 to obtain traffic information. The
commenter also states the Dynon ADS-B uses the same GPS source that is
the subject of this AD.
FAA Response: We are issuing this AD to correct an unsafe condition
that we have determined exists on a NavWorx product. This AD is not
applicable to Trig Avionics (Trig) or Dynon Avionics (Dynon) ADS-B
units. In the case of the older Trig units, installers are responsible
for setting the SIL appropriately based on the qualification of the
position source used. Additionally, neither the Trig units nor the
Dynon units use the SiRF IV position source.
Request: Several commenters noted they purchased a NavWorx unit
because the FAA originally listed them as eligible for the ADS-B Rebate
Program. We interpret these comments as requesting we withdraw the
NPRM.
FAA Response: We have considered the comment. When the FAA rebate
program Web site activated, it listed the ADS600-B as an eligible unit
without distinction by part number. This was consistent with NavWorx's
Web site, www.navworx.com, which advertised the ADS600-B for sale
without distinguishing between the four different unique transceiver
part numbers comprising that model series. P/N 200-0112 and P/N 200-
0113 are 2020 compliant, as these units contain a TSO-C145c approved
Accord NexNav Mini internal GPS. P/N 200-0012 and P/N 200-0013, which
are the subject of this AD, are not 2020 compliant because these units
contain the uncertified SiRF IV GPS. Once the FAA rebate program office
realized that the P/N 200-0012 and 200-0013 units were not eligible for
the rebate, it changed the Web site to identify the ADS600-B model by
P/N and listed only the P/N 200-0112 and P/N 200-0113 units as ADS600-B
equipment selection options. While the FAA regrets any inconvenience
these actions caused, what occurred with the rebate program Web site is
not relevant to whether this AD is necessary to resolve the unsafe
condition presented by the NavWorx units that improperly transmit a SIL
of 3. We did not change the AD based on these comments.
Request: One commenter states the proposed AD is contrary to the
FAA's Compliance Philosophy because we did not cooperate with NavWorx
or provide NavWorx a reasonable time to work on a corrective action.
The commenter requests we withdraw the NPRM, unless we can collect
technical data confirming a safety issue, in which case the commenter
requests any AD be issued in a non-punitive manner.
FAA Response: We disagree. The FAA's Compliance Philosophy applies
to enforcement actions taken for regulatory violations. It does not
apply to ADs, which are rulemaking actions taken to correct unsafe
conditions found in aeronautical products. Notwithstanding, we also
disagree with contentions that we failed to cooperate with NavWorx or
provide NavWorx with a reasonable amount of time to correct the unsafe
condition. The FAA clearly and repeatedly explained to NavWorx the
safety concerns with its ADS-B units and requested that NavWorx
voluntarily make the units TSO-compliant. NavWorx's failure to do so
created an unsafe condition, for which AD action is necessary.
Comment: An individual commenter stated that owners of experimental
aircraft could simply remark the affected part with a new part number
so that the AD wouldn't apply. The commenter reasoned that since the
builder of an experimental aircraft is also the manufacturer, he could
alter the part to a new design and mark it with a new part number.
FAA Response: If the FAA identifies similar problems and determines
that an unsafe condition exists on other part-numbered ADS-B products,
we would take appropriate action to correct that unsafe condition.
Also, simply changing the part number of the unit, without performing
any other corrective action, will not correct the unsafe condition that
we have determined exists in the unit. Since the unsafe condition
remains in the unit, operating an aircraft with such a unit (that has
only had the part number modified with no other corrective action
taken) would therefore be a violation of 14 CFR 91.7(a), which states
that no person may operate a civil aircraft unless it is in an
airworthy condition. Any individual taking such action is subject to a
civil penalty for a violation of the Federal Aviation Regulations.
F. Comments on the Negative Impact of the FAA's Actions
Request: Several commenters stated that the AD would create
confusion or skepticism in the flying community, and will prevent
aircraft owners from adopting new technologies promoted by the FAA in
the future. Some commenters stated that because of the AD people will
quit flying; many others stated aircraft owners will choose to operate
without ADS-B equipment. These commenters requested or implied that we
withdraw the NPRM.
[[Page 25952]]
FAA Response: We disagree. Although the FAA sympathizes with owners
who became early adopters of this technology in good faith and
unfortunately are now adversely affected by a situation not of their
making, the potential for this action to create skepticism and distrust
of the FAA among aircraft owners does not negate the need to correct
the identified unsafe condition. The FAA's failure to take action to
correct this unsafe condition could lead to accidents, which would also
reasonably result in skepticism and distrust of the FAA, not only on
the part of the flying community but of the public at large. We did not
change the AD based on these comments.
Request: A few commenters stated the FAA created this problem by
suddenly and unilaterally changing the operational ADS-B rules to deny
TIS-B data to aircraft broadcasting a SIL of 0. Two of these commenters
noted that NavWorx initially submitted data to substantiate a SIL of 3,
but the FAA refused to grant NavWorx TSO authorization unless the units
broadcast a SIL of 0. The commenters request the FAA provide TIS-B data
to all aircraft, regardless of SIL.
FAA Response: We disagree. The FAA's changes to only provide TIS-B
services to aircraft broadcasting a SIL greater than 0 were neither
sudden nor unilateral. The changes were announced on March 31, 2015,
and became effective in early 2016.\11\ However, they were initiated
several years prior, as the result of an FAA study to determine a low
risk, cost-effective, technically beneficial strategy for modification
of the FAA TIS-B service. During this study, we consulted with the
current manufacturers of ADS-B systems (both certified and uncertified)
designed to use TIS-B information, including Accord Technologies,
Dynon, FreeFlight Systems, Garmin, Honeywell, NavWorx, Rockwell
Collins, and Trig. Like other manufacturers, NavWorx had the
opportunity to make and obtain approval for appropriate design changes
to its equipment so its customers could receive TIS-B traffic after the
service change. NavWorx chose instead to only change the SIL setting
from 0 to 3 in software without demonstrating the existing GPS position
source's qualification to broadcast of a SIL of 3. Since that time, the
FAA has been requesting NavWorx submit testing data supporting its
conclusion that the SiRF IV GPS meets the performance requirements to
broadcast a SIL of 3. NavWorx has not provided the FAA with this data.
---------------------------------------------------------------------------
\11\ A copy of the FAA's announcement of its decision to make
changes to the TIS-B service is available for review in Docket No.
FAA-2016-9226.
---------------------------------------------------------------------------
We also disagree with the contention that NavWorx initially
submitted data to substantiate a SIL of 3. NavWorx's TSO-authorized
design for its P/N 200-0012 and P/N 200-0013 ADS-B units has always
identified the internal GPS source for those units as an uncertified
SiRF IV GPS. The SiRF IV is not manufactured under an FAA TSO. The FAA
approved this equipment and its installation to transmit a SIL of 0
because that is what is required by RTCA Document DO-282B (the
performance standard for TSO-C154c and the NavWorx units) and AC 20-
165B.
The commenters' request to provide TIS-B data to all aircraft,
regardless of SIL, would not correct the unsafe condition. We did not
change the AD based on these comments.
G. Comments Beyond the Scope of the NPRM
Request: A few commenters expressed disagreements with the ADS-B
mandate. One commenter stated compliance with the rule would put him
out of business, because he did not fly often enough to justify the
cost. Another commenter requested the mandate not apply to aircraft
operating under VFR in certain airspace. The third commenter stated
that because of the mandate, the FAA is unable to manage the increase
in ADS-B technology development or deal with the market.
FAA Response: Comments about the 2020 mandate are beyond the scope
of this AD. The rules mandating ADS-B Out usage, 14 CFR 91.225 and
91.227, were promulgated through notice and comment rulemaking that
began with an aviation rulemaking committee. An NPRM was issued in 2007
(72 FR 56947, October 5, 2007) and the comment period was subsequently
re-opened for an additional 30 days in 2008 (73 FR 57270, October 2,
2008). The final rule published on May 28, 2010 (75 FR 30160) and
considered approximately 240 comments from air carriers, manufacturers,
associations, and individuals. All documentation of this rulemaking is
available for review in Docket No. FAA-2007-29305.
Request: Some commenters requested or implied they should be given
until 2025 to comply with the AD because compliance with the ADS-B
mandate is not required for air carriers until 2025.
FAA Response: Comments about the 2020 mandate are beyond the scope
of this AD. It appears the commenters are referring to Exemption No.
12555, which is not a blanket 5-year extension for all air carriers.
Exemption No. 12555 applies only to those operators who submit a
request to use it and who comply with its conditions and limitations.
Exemption No. 12555 allows the use of current ADS-B Out systems that
are not fully compliant with the rule until fully compliant systems are
installed on or before January 1, 2025. Documentation concerning
Exemption No. 12555 is available for review in Docket No. FAA-2015-
0971.
Comment: One commenter described a safety of flight issue he
encountered with a Garmin ADS-B transponder that he has previously
reported to the FAA.
FAA Response: The comment is not relevant to whether this AD is
necessary to correct the unsafe condition presented by the NavWorx ADS-
B units broadcasting a SIL of 0. We did not change the AD based on this
comment.
Comment: A few commenters expressed criticism of the FAA in
general, without requesting specific changes to this AD.
FAA Response: The comments are not relevant to whether this AD is
necessary to correct the unsafe condition presented by the NavWorx ADS-
B units broadcasting a SIL of 0. We did not change the AD based on
these comments.
FAA's Determination
We have reviewed the relevant information, considered the comments
received, and determined that an unsafe condition exists and is likely
to exist or develop on other products of this same type design and that
air safety and the public interest require adopting the AD requirements
as proposed with the changes described previously. These changes are
consistent with the intent of the proposals in the NPRM (81 FR 72552,
October 20, 2016) and will not increase the economic burden on any
operator nor increase the scope of the AD.
Related Service Information
We reviewed NavWorx AFMS for ADS600-B as installed under STC No.
SA11172SC, approved May 4, 2014; NavWorx Installation Manual for
ADS600-B Part 23 AML STC 240-0021-00-07, Revision 7, dated May 4, 2014;
and NavWorx STC Master Drawing List 240-0013-00, Revision 10, dated May
29, 2014. This service information identifies the internal GPS position
source for the NavWorx Model ADS600-B P/N 200-0012 and P/N 200-0013 as
uncertified and not compliant with 14 CFR 91.225 and 91.227.
[[Page 25953]]
Costs of Compliance
We estimate that this AD affects approximately 800 ADS-B units
installed on various aircraft of U.S. registry. Operators may incur the
following costs in order to comply with this AD based on an average
labor rate of $85 per work-hour. Removing the ADS-B unit, disabling the
ADS-B unit, or revising the software of the ADS-B unit will take about
1 work-hour, for a total of $85 per aircraft. Coupling the ADS-B unit
with an approved external GPS will take about 4 work-hours for a total
of $340 per aircraft.
Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
We are issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.
Regulatory Findings
This AD will not have federalism implications under Executive Order
13132. This AD will not have a substantial direct effect on the States,
on the relationship between the national government and the States, or
on the distribution of power and responsibilities among the various
levels of government.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866;
(2) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979);
(3) Will not affect intrastate aviation in Alaska to the extent
that it justifies making a regulatory distinction; and
(4) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
We prepared an economic evaluation of the estimated costs to comply
with this AD and placed it in the AD docket.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):
2017-11-11 NavWorx, Inc.: Amendment 39-18910; Docket No. FAA-2016-
9226; Directorate Identifier 2016-SW-065-AD.
(a) Applicability
This AD applies to the following NavWorx, Inc., Automatic
Dependent Surveillance-Broadcast (ADS-B) Universal Access
Transceiver units (unit) installed on aircraft certificated in any
category, including experimental:
(1) Model ADS600-B part number (P/N) 200-0012;
(2) Model ADS600-B P/N 200-0013; and
(3) Model ADS600-EXP P/N 200-8013.
(b) Unsafe Condition
This AD defines the unsafe condition as an ADS-B unit
incorrectly broadcasting a Source Integrity Level (SIL) of 3 instead
of its authorized SIL of 0. This condition could result in the unit
communicating unreliable position information to Air Traffic Control
and nearby aircraft and a subsequent aircraft collision.
(c) Effective Date
This AD becomes effective July 11, 2017.
(d) Compliance
You are responsible for performing each action required by this
AD within the specified compliance time unless it has already been
accomplished prior to that time.
(e) Required Actions
(1) Within 6 months, comply with either paragraph (e)(1)(i),
(ii), (iii), or (iv) of this AD:
(i) Remove the ADS-B unit.
(ii) Disable and prohibit use of the ADS-B unit as follows:
(A) Pull and secure the circuit breaker and disconnect the
internal GPS antenna connector from the ADS-B unit and secure.
(B) Install a placard in view of the pilot that states ``USING
THE ADS-B SYSTEM IS PROHIBITED.''
(C) Revise the Limitations section of the Aircraft Flight Manual
supplement (AFMS) by inserting a copy of this AD or by making pen-
and-ink changes to add the following: ``USING THE ADS-B SYSTEM IS
PROHIBITED.''
(iii) Revise the software so the ADS-B unit broadcasts a SIL of
0.
(iv) Couple the ADS-B unit with an approved external GPS as
follows:
(A) Interface the ADS-B unit with an Accord NexNav mini LRU GPS
Receiver P/N 21000.
(B) Revise the Limitations section of the AFMS by inserting a
copy of this AD or by making pen-and-ink changes to add the
following: ``OPERATION USING THE INTERNAL POSITION SOURCE IS
PROHIBITED. USE OF THE ACCORD NEXNAV MINI P/N 21000 EXTERNAL
POSITION SOURCE IS REQUIRED.''
(2) After the effective date of this AD, do not install an ADS-B
unit Model ADS600-B P/N 200-0012, Model ADS600-B P/N 200-0013, or
Model ADS600-EXP P/N 200-8013 on any aircraft unless you have
complied with the requirements of paragraph (e)(1)(ii), (e)(1)(iii),
or (e)(1)(iv) of this AD.
(f) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Fort Worth Aircraft Certification Office, FAA,
may approve AMOCs for this AD. Send your proposal to: Kyle Cobble,
Aviation Safety Engineer, Fort Worth Aircraft Certification Office,
Rotorcraft Directorate, FAA, 10101 Hillwood Pkwy, Fort Worth, TX
76177, telephone (817) 222-5172, email kyle.cobble@faa.gov; or
Michael Heusser, Program Manager, Continued Operational Safety
Branch, Fort Worth Aircraft Certification Office, Rotorcraft
Directorate, 10101 Hillwood Pkwy, Fort Worth, TX 76177, telephone
(817) 222-5038, email michael.a.heusser@faa.gov.
(2) For operations conducted under a 14 CFR part 119 operating
certificate or under 14 CFR part 91, subpart K, we suggest that you
notify your principal inspector, or lacking a principal inspector,
the manager of the local flight standards district office or
certificate holding district office before operating any aircraft
complying with this AD through an AMOC.
(g) Additional Information
NavWorx Airplane Flight Manual Supplement for ADS600-B as
installed under Supplemental Type Certificate (STC) No. SA11172SC,
approved May 4, 2014; NavWorx Installation Manual for ADS600-B Part
23 AML STC 240-0021-00-07, Revision 7, dated May 4, 2014; and
NavWorx STC Master Drawing List 240-0013-00, Revision 10, dated May
29, 2014, which are not incorporated by reference, contain
additional information about the subject of this AD. For service
information identified in this AD, contact NavWorx Inc.; telephone
(888) 628-9679; email: support@navworx.com or at www.navworx.com.
You may review a copy of this information at the FAA, Office of the
Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N-
321, Fort Worth, TX 76177.
(h) Subject
Joint Aircraft Service Component (JASC) Code: 3452, ATC
Transponder System.
[[Page 25954]]
Issued in Fort Worth, Texas, on May 30, 2017.
Lance T. Gant,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 2017-11625 Filed 6-5-17; 8:45 am]
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