Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 Series Airplanes, 18249-18251 [06-3441]
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Federal Register / Vol. 71, No. 69 / Tuesday, April 11, 2006 / Proposed Rules
compartment door, replace the seal on both
partitions with a new seal, and accomplish
all applicable corrective actions, by doing all
the actions specified in the Accomplishment
Instructions of EMBRAER Service Bulletin
145LEG–25–0060, dated November 18, 2005.
All applicable corrective actions must be
done before further flight.
Note 1: For the purposes of this AD, a
general visual inspection is: ‘‘A visual
examination of an interior or exterior area,
installation, or assembly to detect obvious
damage, failure, or irregularity. This level of
inspection is made from within touching
distance unless otherwise specified. A mirror
may be necessary to ensure visual access to
all surfaces in the inspection area. This level
of inspection is made under normally
available lighting conditions such as
daylight, hangar lighting, flashlight, or
droplight and may require removal or
opening of access panels or doors. Stands,
ladders, or platforms may be required to gain
proximity to the area being checked.’’
Alternative Methods of Compliance
(AMOCs)
(g)(1) The Manager, International Branch,
ANM–116, Transport Airplane Directorate,
FAA, has the authority to approve AMOCs
for this AD, if requested in accordance with
the procedures found in 14 CFR 39.19.
(2) Before using any AMOC approved in
accordance with § 39.19 on any airplane to
which the AMOC applies, notify the
appropriate principal inspector in the FAA
Flight Standards Certificate Holding District
Office.
Related Information
(h) Brazilian airworthiness directive 2006–
02–02, dated February 24, 2006, also
addresses the subject of this AD.
Issued in Renton, Washington, on March
30, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate,
Aircraft Certification Service.
[FR Doc. 06–3440 Filed 4–10–06; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2006–24368; Directorate
Identifier 2005–NM–230–AD]
RIN 2120–AA64
hsrobinson on PROD1PC70 with PROPOSALS
Airworthiness Directives; McDonnell
Douglas Model DC–9–10, –20, –30, –40,
and –50 Series Airplanes
Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking
(NPRM).
AGENCY:
SUMMARY: The FAA proposes to adopt a
new airworthiness directive (AD) for all
VerDate Aug<31>2005
15:25 Apr 10, 2006
Jkt 208001
McDonnell Douglas Model DC–9–10,
–20, –30, –40, and –50 series airplanes.
This proposed AD would require
replacing the clamp bases for the fuel
vent pipe with improved clamp bases.
This proposed AD results from reports
that the foil wrapping on existing plastic
clamp bases has migrated out of
position, which compromises the
bonding of the fuel vent lines to the
airplane structure. We are proposing
this AD to ensure that the fuel vent lines
are properly bonded to the airplane
structure. Improper bonding could
prevent electrical energy from a
lightning strike from dissipating to the
airplane structure, and create an
ignition source, which could result in a
fuel tank explosion.
DATES: We must receive comments on
this proposed AD by May 26, 2006.
ADDRESSES: Use one of the following
addresses to submit comments on this
proposed AD.
• DOT Docket Web site: Go to
https://dms.dot.gov and follow the
instructions for sending your comments
electronically.
• Government-wide rulemaking Web
site: Go to https://www.regulations.gov
and follow the instructions for sending
your comments electronically.
• Mail: Docket Management Facility,
U.S. Department of Transportation, 400
Seventh Street SW., Nassif Building,
room PL–401, Washington, DC 20590.
• Fax: (202) 493–2251.
• Hand Delivery: Room PL–401 on
the plaza level of the Nassif Building,
400 Seventh Street SW., Washington,
DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
Contact Boeing Commercial
Airplanes, Long Beach Division, 3855
Lakewood Boulevard, Long Beach,
California 90846, Attention: Data and
Service Management, Dept. C1–L5A
(D800–0024), for the service information
identified in this proposed AD.
FOR FURTHER INFORMATION CONTACT: Serj
Harutunian, Aerospace Engineer,
Propulsion Branch, ANM–140L, FAA,
Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard,
Lakewood, California 90712–4137;
telephone (562) 627–5254; fax (562)
627–5210.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to submit any relevant
written data, views, or arguments
regarding this proposed AD. Send your
comments to an address listed in the
ADDRESSES section. Include the docket
number ‘‘FAA–2006–24368; Directorate
Identifier 2005–NM–230–AD’’ at the
beginning of your comments. We
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Fmt 4702
Sfmt 4702
18249
specifically invite comments on the
overall regulatory, economic,
environmental, and energy aspects of
the proposed AD. We will consider all
comments received by the closing date
and may amend the proposed AD in
light of those comments.
We will post all comments we
receive, without change, to https://
dms.dot.gov, including any personal
information you provide. We will also
post a report summarizing each
substantive verbal contact with FAA
personnel concerning this proposed AD.
Using the search function of that Web
site, anyone can find and read the
comments in any of our dockets,
including the name of the individual
who sent the comment (or signed the
comment on behalf of an association,
business, labor union, etc.). You may
review DOT’s complete Privacy Act
Statement in the Federal Register
published on April 11, 2000 (65 FR
19477–78), or you may visit https://
dms.dot.gov.
Examining the Docket
You may examine the AD docket on
the Internet at https://dms.dot.gov, or in
person at the Docket Management
Facility office between 9 a.m. and 5
p.m., Monday through Friday, except
Federal holidays. The Docket
Management Facility office (telephone
(800) 647–5227) is located on the plaza
level of the Nassif Building at the DOT
street address stated in the ADDRESSES
section. Comments will be available in
the AD docket shortly after the Docket
Management System receives them.
Discussion
The FAA has examined the
underlying safety issues involved in fuel
tank explosions on several large
transport airplanes, including the
adequacy of existing regulations, the
service history of airplanes subject to
those regulations, and existing
maintenance practices for fuel tank
systems. As a result of those findings,
we issued a regulation titled ‘‘Transport
Airplane Fuel Tank System Design
Review, Flammability Reduction and
Maintenance and Inspection
Requirements’’ (67 FR 23086, May 7,
2001). In addition to new airworthiness
standards for transport airplanes and
new maintenance requirements, this
rule included Special Federal Aviation
Regulation No. 88 (‘‘SFAR 88,’’
Amendment 21–78, and subsequent
Amendments 21–82 and 21–83).
Among other actions, SFAR 88
requires certain type design (i.e., type
certificate (TC) and supplemental type
certificate (STC)) holders to substantiate
that their fuel tank systems can prevent
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Federal Register / Vol. 71, No. 69 / Tuesday, April 11, 2006 / Proposed Rules
hsrobinson on PROD1PC70 with PROPOSALS
ignition sources in the fuel tanks. This
requirement applies to type design
holders for large turbine-powered
transport airplanes and for subsequent
modifications to those airplanes. It
requires them to perform design reviews
and to develop design changes and
maintenance procedures if their designs
do not meet the new fuel tank safety
standards. As explained in the preamble
to the rule, we intended to adopt
airworthiness directives to mandate any
changes found necessary to address
unsafe conditions identified as a result
of these reviews.
In evaluating these design reviews, we
have established four criteria intended
to define the unsafe conditions
associated with fuel tank systems that
require corrective actions. The
percentage of operating time during
which fuel tanks are exposed to
flammable conditions is one of these
criteria. The other three criteria address
the failure types under evaluation:
single failures, single failures in
combination with a latent condition(s),
and in-service failure experience. For all
four criteria, the evaluations included
consideration of previous actions taken
that may mitigate the need for further
action.
We have determined that the actions
identified in this AD are necessary to
reduce the potential of ignition sources
inside fuel tanks, which, in combination
with flammable fuel vapors, could result
in fuel tank explosions and consequent
loss of the airplane.
Foil-wrapped plastic clamp bases are
used to bond the fuel vent line to the
airplane structure in parts of the fuel
vent system on McDonnell Douglas
Model DC–9–10, –20, –30, –40, and –50
series airplanes. We have received
reports that the foil wrapping on
existing plastic clamp bases has
migrated out of position on several
airplanes, which compromises the
bonding of the fuel vent lines to the
airplane structure. Bonding of the fuel
vent lines to the airplane structure is
critical to ensure that the electrical
energy from a lightning strike dissipates
to the airplane structure. This condition,
if not corrected, could create an ignition
source and result in a fuel tank
explosion.
Relevant Service Information
We have reviewed Boeing Service
Bulletin DC9–28–211, dated February
23, 2005. The service bulletin describes
procedures for replacing existing foilwrapped plastic clamp bases for the fuel
vent line with improved metal clamp
bases. These replacement procedures
include verifying the electrical
conductivity of the structural bracket
VerDate Aug<31>2005
15:25 Apr 10, 2006
Jkt 208001
and vent pipe surfaces using an
ohmmeter and taking corrective action if
necessary. If the ohmmeter reading is
more than 2.5 milliohms, the corrective
action includes prepping and applying
chemical conversion coating to the
surface of the structural bracket and/or
vent pipe, as applicable. Accomplishing
the actions specified in the service
information is intended to adequately
address the unsafe condition.
FAA’s Determination and Requirements
of the Proposed AD
We have evaluated all pertinent
information and identified an unsafe
condition that is likely to exist or
develop on other airplanes of this same
type design. For this reason, we are
proposing this AD, which would require
accomplishing the actions specified in
the service information described
previously, except as discussed under
‘‘Differences Between the Proposed AD
and Service Bulletin.’’
Differences Between the Proposed AD
and Service Bulletin
Although the service bulletin
recommends accomplishing the
replacement of clamp bases for the fuel
vent line within 10 years after the issue
date of the service bulletin, we have
determined that interval would not
address the identified unsafe condition
soon enough to ensure an adequate level
of safety for the affected fleet. In
developing an appropriate compliance
time for this AD, we considered the
manufacturer’s recommendation, the
degree of urgency associated with the
subject unsafe condition, and the time
necessary to do the replacement. In light
of all of these factors, we find that a 60month compliance time represents an
appropriate interval of time for affected
airplanes to continue to operate without
compromising safety. This difference
has been coordinated with Boeing, and
Boeing concurs.
Costs of Compliance
There are about 640 airplanes of the
affected design in the worldwide fleet.
This proposed AD would affect about
413 airplanes of U.S. registry. The
proposed actions would take up to 4
work hours per airplane, at an average
labor rate of $80 per work hour.
Required parts would cost between
$1,004 and $2,008 per airplane. Based
on these figures, the estimated cost of
the proposed AD for U.S. operators is
between $546,812 and $961,464, or
$1,324 and $2,328 per airplane.
Authority for This Rulemaking
Title 49 of the United States Code
specifies the FAA’s authority to issue
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Fmt 4702
Sfmt 4702
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
We have determined that this
proposed AD would not have federalism
implications under Executive Order
13132. This proposed AD would 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 the proposed regulation:
1. Is not a ‘‘significant regulatory
action’’ under Executive Order 12866;
2. Is not a ‘‘significant rule’’ under the
DOT Regulatory Policies and Procedures
(44 FR 11034, February 26, 1979); and
3. 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 a regulatory evaluation
of the estimated costs to comply with
this proposed AD and placed it in the
AD docket. See the ADDRESSES section
for a location to examine the regulatory
evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation
safety, Safety.
The Proposed Amendment
Accordingly, under the authority
delegated to me by the Administrator,
the FAA proposes to amend 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.
E:\FR\FM\11APP1.SGM
11APP1
Federal Register / Vol. 71, No. 69 / Tuesday, April 11, 2006 / Proposed Rules
§ 39.13
[Amended]
2. The Federal Aviation
Administration (FAA) amends § 39.13
by adding the following new
airworthiness directive (AD):
McDonnell Douglas: Docket No. FAA–2006–
24368; Directorate Identifier 2005–NM–
230–AD.
Issued in Renton, Washington, on March
30, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate,
Aircraft Certification Service.
[FR Doc. 06–3441 Filed 4–10–06; 8:45 am]
BILLING CODE 4910–13–P
Comments Due Date
DEPARTMENT OF TRANSPORTATION
(a) The FAA must receive comments on
this AD action by May 26, 2006.
Federal Aviation Administration
Affected ADs
14 CFR Part 39
(b) None.
[Docket No. FAA–2006–24369; Directorate
Identifier 2006–NM–001–AD]
Applicability
(c) This AD applies to all McDonnell
Douglas Model DC–9–11, DC–9–12, DC–9–
13, DC–9–14, DC–9–15, DC–9–15F, DC–9–21,
DC–9–31, DC–9–32, DC–9–32 (VC–9C), DC–
9–32F, DC–9–32F (C–9A, C–9B), DC–9–33F,
DC–9–34, DC–9–34F, DC–9–41, and DC–9–51
airplanes, certificated in any category.
Unsafe Condition
(d) This AD results from reports that the
foil wrapping on existing plastic clamp bases
has migrated out of position, which
compromises the bonding of the fuel vent
lines to the airplane structure. We are issuing
this AD to ensure that the fuel vent lines are
properly bonded to the airplane structure.
Improper bonding could prevent electrical
energy from a lightning strike from
dissipating to the airplane structure, and
create an ignition source, which could result
in a fuel tank explosion.
Compliance
(e) You are responsible for having the
actions required by this AD performed within
the compliance times specified, unless the
actions have already been done.
Clamp Base Replacement
(f) Within 60 months after the effective
date of this AD, replace the existing clamp
bases for the fuel vent line with improved
metal clamp bases, by doing all of the
applicable actions in accordance with the
Accomplishment Instructions of Boeing
Service Bulletin DC9–28–211, dated February
23, 2005. Any corrective action that is
required following the conductivity
verification, which is included in the
replacement procedures, must be done before
further flight.
hsrobinson on PROD1PC70 with PROPOSALS
Alternative Methods of Compliance
(AMOCs)
(g)(1) The Manager, Los Angeles Aircraft
Certification Office (ACO), FAA, has the
authority to approve AMOCs for this AD, if
requested in accordance with the procedures
found in 14 CFR 39.19.
(2) Before using any AMOC approved in
accordance with § 39.19 on any airplane to
which the AMOC applies, notify the
appropriate principal inspector in the FAA
Flight Standards Certificate Holding District
Office.
VerDate Aug<31>2005
15:25 Apr 10, 2006
Jkt 208001
RIN 2120–AA64
Airworthiness Directives; Boeing
Model 737–600, –700, –700C, and –800
Series Airplanes
Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking
(NPRM).
AGENCY:
SUMMARY: The FAA proposes to
supersede an existing airworthiness
directive (AD) that applies to certain
Boeing Model 737–600, –700, –700C,
and –800 series airplanes. The existing
AD currently requires replacing the
point ‘‘D’’ splice fitting between
windows number 1 and 2 with a new
splice fitting; performing an eddy
current inspection for cracking of the
holes in the structure common to the
new splice fitting, including doing any
related investigative actions; and
performing corrective actions if
necessary. This proposed AD would add
repetitive inspections for cracking of the
skin just below each splice fitting, and
related corrective actions if necessary.
This proposed AD results from full-scale
fuselage fatigue testing on the splice
fitting that failed prior to the design
objective on Boeing Model 737–800
series airplanes, and a report of a
cracked splice fitting on an operational
airplane. We are proposing this AD to
prevent cracking of the existing fitting,
which may result in cracking through
the skin and consequent decompression
of the flight cabin.
DATES: We must receive comments on
this proposed AD by May 26, 2006.
ADDRESSES: Use one of the following
addresses to submit comments on this
proposed AD.
• DOT Docket Web site: Go to
https://dms.dot.gov and follow the
instructions for sending your comments
electronically.
• Government-wide rulemaking Web
site: Go to https://www.regulations.gov
PO 00000
Frm 00021
Fmt 4702
Sfmt 4702
18251
and follow the instructions for sending
your comments electronically.
• Mail: Docket Management Facility;
U.S. Department of Transportation, 400
Seventh Street SW., Nassif Building,
room PL–401, Washington, DC 20590.
• Fax: (202) 493–2251.
• Hand Delivery: Room PL–401 on
the plaza level of the Nassif Building,
400 Seventh Street SW., Washington,
DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
Contact Boeing Commercial
Airplanes, P.O. Box 3707, Seattle,
Washington 98124–2207, for service
information identified in this proposed
AD.
FOR FURTHER INFORMATION CONTACT: Sue
Lucier, Aerospace Engineer, Airframe
Branch, ANM–120S, FAA, Seattle
Aircraft Certification Office, 1601 Lind
Avenue, SW., Renton, Washington
98055–4056; telephone (425) 917–6438;
fax (425) 917–6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to submit any relevant
written data, views, or arguments
regarding this proposed AD. Send your
comments to an address listed in the
ADDRESSES section. Include the docket
number ‘‘Docket No. FAA–2006–24369;
Directorate Identifier 2006–NM–001–
AD’’ at the beginning of your comments.
We specifically invite comments on the
overall regulatory, economic,
environmental, and energy aspects of
the proposed AD. We will consider all
comments received by the closing date
and may amend the proposed AD in
light of those comments.
We will post all comments we
receive, without change, to https://
dms.dot.gov, including any personal
information you provide. We will also
post a report summarizing each
substantive verbal contact with FAA
personnel concerning this proposed AD.
Using the search function of that Web
site, anyone can find and read the
comments in any of our dockets,
including the name of the individual
who sent the comment (or signed the
comment on behalf of an association,
business, labor union, etc.). You may
review the DOT’s complete Privacy Act
Statement in the Federal Register
published on April 11, 2000 (65 FR
19477–78), or visit https://dms.dot.gov.
Examining the Docket
You may examine the AD docket on
the Internet at https://dms.dot.gov, or in
person at the Docket Management
Facility office between 9 a.m. and 5
p.m., Monday through Friday, except
Federal holidays. The Docket
E:\FR\FM\11APP1.SGM
11APP1
]]>Agencies
[Federal Register Volume 71, Number 69 (Tuesday, April 11, 2006)]
[Proposed Rules]
[Pages 18249-18251]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-3441]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2006-24368; Directorate Identifier 2005-NM-230-AD]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, -
30, -40, and -50 Series Airplanes
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for all McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series
airplanes. This proposed AD would require replacing the clamp bases for
the fuel vent pipe with improved clamp bases. This proposed AD results
from reports that the foil wrapping on existing plastic clamp bases has
migrated out of position, which compromises the bonding of the fuel
vent lines to the airplane structure. We are proposing this AD to
ensure that the fuel vent lines are properly bonded to the airplane
structure. Improper bonding could prevent electrical energy from a
lightning strike from dissipating to the airplane structure, and create
an ignition source, which could result in a fuel tank explosion.
DATES: We must receive comments on this proposed AD by May 26, 2006.
ADDRESSES: Use one of the following addresses to submit comments on
this proposed AD.
DOT Docket Web site: Go to https://dms.dot.gov and follow
the instructions for sending your comments electronically.
Government-wide rulemaking Web site: Go to https://
www.regulations.gov and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility, U.S. Department of
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401,
Washington, DC 20590.
Fax: (202) 493-2251.
Hand Delivery: Room PL-401 on the plaza level of the
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m.
and 5 p.m., Monday through Friday, except Federal holidays.
Contact Boeing Commercial Airplanes, Long Beach Division, 3855
Lakewood Boulevard, Long Beach, California 90846, Attention: Data and
Service Management, Dept. C1-L5A (D800-0024), for the service
information identified in this proposed AD.
FOR FURTHER INFORMATION CONTACT: Serj Harutunian, Aerospace Engineer,
Propulsion Branch, ANM-140L, FAA, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137;
telephone (562) 627-5254; fax (562) 627-5210.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to submit any relevant written data, views, or
arguments regarding this proposed AD. Send your comments to an address
listed in the ADDRESSES section. Include the docket number ``FAA-2006-
24368; Directorate Identifier 2005-NM-230-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of the proposed AD. We will
consider all comments received by the closing date and may amend the
proposed AD in light of those comments.
We will post all comments we receive, without change, to https://
dms.dot.gov, including any personal information you provide. We will
also post a report summarizing each substantive verbal contact with FAA
personnel concerning this proposed AD. Using the search function of
that Web site, anyone can find and read the comments in any of our
dockets, including the name of the individual who sent the comment (or
signed the comment on behalf of an association, business, labor union,
etc.). You may review DOT's complete Privacy Act Statement in the
Federal Register published on April 11, 2000 (65 FR 19477-78), or you
may visit https://dms.dot.gov.
Examining the Docket
You may examine the AD docket on the Internet at https://
dms.dot.gov, or in person at the Docket Management Facility office
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT
street address stated in the ADDRESSES section. Comments will be
available in the AD docket shortly after the Docket Management System
receives them.
Discussion
The FAA has examined the underlying safety issues involved in fuel
tank explosions on several large transport airplanes, including the
adequacy of existing regulations, the service history of airplanes
subject to those regulations, and existing maintenance practices for
fuel tank systems. As a result of those findings, we issued a
regulation titled ``Transport Airplane Fuel Tank System Design Review,
Flammability Reduction and Maintenance and Inspection Requirements''
(67 FR 23086, May 7, 2001). In addition to new airworthiness standards
for transport airplanes and new maintenance requirements, this rule
included Special Federal Aviation Regulation No. 88 (``SFAR 88,''
Amendment 21-78, and subsequent Amendments 21-82 and 21-83).
Among other actions, SFAR 88 requires certain type design (i.e.,
type certificate (TC) and supplemental type certificate (STC)) holders
to substantiate that their fuel tank systems can prevent
[[Page 18250]]
ignition sources in the fuel tanks. This requirement applies to type
design holders for large turbine-powered transport airplanes and for
subsequent modifications to those airplanes. It requires them to
perform design reviews and to develop design changes and maintenance
procedures if their designs do not meet the new fuel tank safety
standards. As explained in the preamble to the rule, we intended to
adopt airworthiness directives to mandate any changes found necessary
to address unsafe conditions identified as a result of these reviews.
In evaluating these design reviews, we have established four
criteria intended to define the unsafe conditions associated with fuel
tank systems that require corrective actions. The percentage of
operating time during which fuel tanks are exposed to flammable
conditions is one of these criteria. The other three criteria address
the failure types under evaluation: single failures, single failures in
combination with a latent condition(s), and in-service failure
experience. For all four criteria, the evaluations included
consideration of previous actions taken that may mitigate the need for
further action.
We have determined that the actions identified in this AD are
necessary to reduce the potential of ignition sources inside fuel
tanks, which, in combination with flammable fuel vapors, could result
in fuel tank explosions and consequent loss of the airplane.
Foil-wrapped plastic clamp bases are used to bond the fuel vent
line to the airplane structure in parts of the fuel vent system on
McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series
airplanes. We have received reports that the foil wrapping on existing
plastic clamp bases has migrated out of position on several airplanes,
which compromises the bonding of the fuel vent lines to the airplane
structure. Bonding of the fuel vent lines to the airplane structure is
critical to ensure that the electrical energy from a lightning strike
dissipates to the airplane structure. This condition, if not corrected,
could create an ignition source and result in a fuel tank explosion.
Relevant Service Information
We have reviewed Boeing Service Bulletin DC9-28-211, dated February
23, 2005. The service bulletin describes procedures for replacing
existing foil-wrapped plastic clamp bases for the fuel vent line with
improved metal clamp bases. These replacement procedures include
verifying the electrical conductivity of the structural bracket and
vent pipe surfaces using an ohmmeter and taking corrective action if
necessary. If the ohmmeter reading is more than 2.5 milliohms, the
corrective action includes prepping and applying chemical conversion
coating to the surface of the structural bracket and/or vent pipe, as
applicable. Accomplishing the actions specified in the service
information is intended to adequately address the unsafe condition.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other airplanes
of this same type design. For this reason, we are proposing this AD,
which would require accomplishing the actions specified in the service
information described previously, except as discussed under
``Differences Between the Proposed AD and Service Bulletin.''
Differences Between the Proposed AD and Service Bulletin
Although the service bulletin recommends accomplishing the
replacement of clamp bases for the fuel vent line within 10 years after
the issue date of the service bulletin, we have determined that
interval would not address the identified unsafe condition soon enough
to ensure an adequate level of safety for the affected fleet. In
developing an appropriate compliance time for this AD, we considered
the manufacturer's recommendation, the degree of urgency associated
with the subject unsafe condition, and the time necessary to do the
replacement. In light of all of these factors, we find that a 60-month
compliance time represents an appropriate interval of time for affected
airplanes to continue to operate without compromising safety. This
difference has been coordinated with Boeing, and Boeing concurs.
Costs of Compliance
There are about 640 airplanes of the affected design in the
worldwide fleet. This proposed AD would affect about 413 airplanes of
U.S. registry. The proposed actions would take up to 4 work hours per
airplane, at an average labor rate of $80 per work hour. Required parts
would cost between $1,004 and $2,008 per airplane. Based on these
figures, the estimated cost of the proposed AD for U.S. operators is
between $546,812 and $961,464, or $1,324 and $2,328 per airplane.
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
We have determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 the proposed
regulation:
1. Is not a ``significant regulatory action'' under Executive Order
12866;
2. Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979); and
3. 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 a regulatory evaluation of the estimated costs to
comply with this proposed AD and placed it in the AD docket. See the
ADDRESSES section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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.
[[Page 18251]]
Sec. 39.13 [Amended]
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by
adding the following new airworthiness directive (AD):
McDonnell Douglas: Docket No. FAA-2006-24368; Directorate Identifier
2005-NM-230-AD.
Comments Due Date
(a) The FAA must receive comments on this AD action by May 26,
2006.
Affected ADs
(b) None.
Applicability
(c) This AD applies to all McDonnell Douglas Model DC-9-11, DC-
9-12, DC-9-13, DC-9-14, DC-9-15, DC-9-15F, DC-9-21, DC-9-31, DC-9-
32, DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A, C-9B), DC-9-33F, DC-
9-34, DC-9-34F, DC-9-41, and DC-9-51 airplanes, certificated in any
category.
Unsafe Condition
(d) This AD results from reports that the foil wrapping on
existing plastic clamp bases has migrated out of position, which
compromises the bonding of the fuel vent lines to the airplane
structure. We are issuing this AD to ensure that the fuel vent lines
are properly bonded to the airplane structure. Improper bonding
could prevent electrical energy from a lightning strike from
dissipating to the airplane structure, and create an ignition
source, which could result in a fuel tank explosion.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.
Clamp Base Replacement
(f) Within 60 months after the effective date of this AD,
replace the existing clamp bases for the fuel vent line with
improved metal clamp bases, by doing all of the applicable actions
in accordance with the Accomplishment Instructions of Boeing Service
Bulletin DC9-28-211, dated February 23, 2005. Any corrective action
that is required following the conductivity verification, which is
included in the replacement procedures, must be done before further
flight.
Alternative Methods of Compliance (AMOCs)
(g)(1) The Manager, Los Angeles Aircraft Certification Office
(ACO), FAA, has the authority to approve AMOCs for this AD, if
requested in accordance with the procedures found in 14 CFR 39.19.
(2) Before using any AMOC approved in accordance with Sec.
39.19 on any airplane to which the AMOC applies, notify the
appropriate principal inspector in the FAA Flight Standards
Certificate Holding District Office.
Issued in Renton, Washington, on March 30, 2006.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 06-3441 Filed 4-10-06; 8:45 am]
BILLING CODE 4910-13-P
