Revisions to Cockpit Voice Recorder and Digital Flight Data Recorder Regulations, 12542-12573 [E8-3949]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 73, Number 46 (Friday, March 7, 2008)]
[Rules and Regulations]
[Pages 12542-12573]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-3949]



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Part III





Department of Transportation





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Federal Aviation Administration



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14 CFR Parts 23, 25, 27 et al.



Revisions to Cockpit Voice Recorder and Digital Flight Data Recorder 
Regulations; Final Rule

Federal Register / Vol. 73, No. 46 / Friday, March 7, 2008 / Rules 
and Regulations

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 23, 25, 27, 29, 91, 121, 125, 129 and 135

[Docket No. FAA-2005-20245; Amendment No. 23-58, 25-124, 27-43, 29-50, 
91-300, 121-338, 125-54, 129-45, and 135-113]
RIN 2120-AH88


Revisions to Cockpit Voice Recorder and Digital Flight Data 
Recorder Regulations

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: This final rule amends cockpit voice recorder (CVR) and 
digital flight data recorder (DFDR) regulations affecting certain air 
carriers, operators, and aircraft manufacturers. This final rule 
increases the duration of certain CVR recordings, increases the data 
recording rate for certain DFDR parameters, requires physical 
separation of the DFDR and CVR, improves the reliability of the power 
supplies to both the CVR and DFDR, and requires that certain datalink 
communications received on an aircraft be recorded if datalink 
communication equipment is installed. This final rule is based on 
recommendations issued by the National Transportation Safety Board 
following its investigations of several accidents and incidents, and 
includes other revisions the FAA has determined are necessary. These 
changes to CVR and DFDR systems are intended to improve the quality and 
quantity of information recorded, and increase the potential for 
retaining important information needed for accident and incident 
investigations.

DATES: These amendments become effective April 7, 2008.

FOR FURTHER INFORMATION CONTACT: For technical questions contact: 
Timothy W. Shaver, Avionics Systems Branch, Aircraft Certification 
Service, AIR-130, Federal Aviation Administration, 800 Independence 
Avenue, SW., Washington, DC 20591; telephone (202) 385-4686; facsimile 
(202) 385-4651; e-mail tim.shaver@faa.gov. For legal questions contact: 
Karen L. Petronis, Regulations Division, Office of the Chief Counsel, 
Federal Aviation Administration, 800 Independence Avenue, SW., 
Washington, DC 20591; telephone (202) 267-3073; facsimile (202) 267-
3073; e-mail karen.petronis@faa.gov.

SUPPLEMENTARY INFORMATION:

Authority for This Rulemaking

    The FAA's authority to issue rules regarding aviation safety is 
found in Title 49 of the United States Code. 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.
    This rulemaking is promulgated under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701. Under that section, 
the FAA is charged with prescribing regulations providing minimum 
standards for other practices, methods and procedures necessary for 
safety in air commerce. This regulation is within the scope of that 
authority since flight data recorders are the only means available to 
account for aircraft movement and flight crew actions critical to 
finding the probable cause of incidents or accidents, including data 
that could prevent future incidents or accidents.

Background

A. Statement of the Problem

    For many years, the National Transportation Safety Board (NTSB) has 
experienced difficulties while investigating aircraft accidents and 
incidents. The information recorded on cockpit voice recorders (CVRs) 
and Digital Flight Data Recorders (DFDRs) has not always been 
sufficient to support the NTSB's investigations. The problems 
encountered by the NTSB include the limited duration of CVR recordings 
preceding an incident, and the loss of power to both CVRs and DFDRs. 
These issues arose in the investigation of the following accidents and 
incidents: Alaska Airlines, Inc. flight 261 on January 31, 2000; 
EgyptAir flight 990 on October 31, 1999; Delta Air Lines, Inc. flight 
2461 on December 15, 1998; Swissair flight 111 on September 2, 1998; 
SilkAir flight 185 on December 19, 1997; ValuJet Airlines flight 592 on 
May 11, 1996; Trans World Airlines, Inc. flight 800 on July 17, 1996; 
and ValuJet Airlines flight 597 on June 8, 1995. The notice of proposed 
rulemaking that preceded this final rule was published on February 28, 
2005 (``Revisions to Cockpit Voice Recorder and Digital Flight Data 
Recorder Regulations,'' 70 FR 9752) and discusses these accidents and 
incidents in more detail, starting on page 9753.

B. NTSB Recommendations

    Based on its findings following these investigations, the NTSB 
issued five safety recommendations for improving the flight recorder 
systems on all aircraft required to carry a CVR and a DFDR.
    Recommendation No. A-96-89. Within two years, require all aircraft 
required to have a CVR to be retrofitted with a CVR that receives, on 
dedicated channels, (1) uninterrupted input from the boom or mask 
microphone and headphones of each crewmember; and (2) uninterrupted 
input from an area microphone. During these recordings, a sidetone must 
be produced only when the transmitter or interphone is selected. 
Finally, all audio signals received by hand-held microphones must be 
recorded on the respective flight crewmember's channel when keyed to 
the ``ON'' position.
    Recommendation No. A-96-171. Require that all newly manufactured 
CVRs intended for use on airplanes have a minimum recording duration of 
two hours.
    Recommendation No. A-99-16. By January 1, 2005, retrofit all 
airplanes that are required to carry a CVR and an FDR with a CVR that 
(1) meets the standards of the Technical Standard Order on Cockpit 
Voice Recorder Systems, TSO-C123a, or later revision; (2) is capable of 
recording the last two hours of audio; and (3) is fitted with a 10-
minute independent power source that is located with the CVR and that 
automatically engages and provides 10 minutes of operation whenever 
power to the recorder ceases, either by normal shutdown or by a loss of 
power to the bus.
    Recommendation No. A-99-17. Require all aircraft manufactured after 
January 1, 2003, that are required to carry a CVR and a DFDR, to be 
equipped with two combination (CVR/DFDR) recording systems. One system 
should be located as close to the cockpit as practicable and the other 
as far aft as practicable. Both recording systems should be capable of 
recording all mandatory data parameters covering the previous 25 hours 
of operation and all cockpit audio and controller-pilot datalink 
communications for the previous two hours of operation. The system 
located near the cockpit should be provided with an independent power 
source that engages automatically and provides 10 minutes of operation 
whenever normal aircraft power ceases. The aft system should be powered 
by the bus that provides the maximum reliability for operation without 
jeopardizing service to essential or emergency loads. The system near 
the cockpit should be powered by the bus that provides the second 
highest reliability for operation without jeopardizing service to 
essential or emergency loads.
    Recommendation No. A-99-18. Amend Sec.  25.1457 (for CVRs) and

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Sec.  25.1459 (for DFDRs) to require that CVRs, DFDRs, and redundant 
combination CVR/DFDR units be powered from separate generator buses 
with the highest reliability.

C. Summary of the NPRM

    In February 2005, we proposed changes to the regulations that 
address the NTSB's recommendations (70 FR 9752; February 28, 2005)(the 
NPRM). We agreed with recommendation Nos. A-96-89, A-96-171, A-99-18, 
and parts of Nos. A-99-16 and A-99-17.
    In the NPRM, we proposed that all CVRs be able to retain the last 
two hours of cockpit conversation, and that a better technical standard 
for equipment be mandatory. We proposed that aircraft carry an 
independent power source to power CVRs for 10 minutes after main power 
sources fail. We also proposed language to standardize across operating 
parts when a CVR is operated.
    We proposed wiring requirements that would ensure that each CVR and 
DFDR receives its electrical power from the bus that provides the 
maximum reliability for operation of each recorder without jeopardizing 
service to essential or emergency loads. Each recorder also must remain 
powered for as long as possible without jeopardizing emergency 
operation of the aircraft. These requirements would apply to newly 
manufactured aircraft.
    We proposed that CVRs and DFDRs be installed in separate containers 
in all airplanes; rotorcraft would be allowed to have a single combined 
unit for both recorders. For aircraft that have both a CVR and a DFDR, 
we proposed that the interphone communications requirements described 
in the certification rules apply to all part 23 and part 25 airplanes.
    We proposed increased data recording rates for certain flight 
control parameters that would apply to both airplanes and rotorcraft.
    We proposed that datalink communications be recorded when datalink 
systems are installed on airplanes after a certain date, and we sought 
comment on the nature and scope of what should be required to be 
recorded, acknowledging that the state of the technology is still 
developing.
    We did not propose to adopt the NTSB recommendation that the 10-
minute CVR power supply be installed as a retrofit on current aircraft, 
that aircraft carry a deployable recorder system, or that each airplane 
carry two complete recording systems. In evaluating these 
recommendations, we determined that the anticipated costs were too 
great to justify any potential benefit, or that there was insufficient 
data to compare probable costs and benefits. We did request comment on 
each of these items.
    A more detailed discussion of each proposed change can be found in 
the NPRM document on pages 9755-9762.

Discussion of Comments

A. General Summary

    The FAA received 55 submissions from 53 commenters (two commenters 
each submitted two comments) in response to the NPRM.
    Six commenters supported the proposal in its entirety. Thirty-two 
commenters generally supported the intent, but offered detailed 
alternatives or changes to various sections. The supporting commenters 
included airframe manufacturers, aircraft operators, industry 
associations, an accident investigator, and several individuals.
    Three commenters opposed the proposal in its entirety and requested 
that we either abandon or postpone the proposed requirements. One 
commenter did not specifically state opposition, but it was inferred 
from the comment. Eight commenters objected to the proposed changes 
specifically for part 27 and part 29 rotorcraft, for part 91 and part 
135 aircraft, or for aircraft with fewer than 60 seats. Some of these 
commenters also questioned the FAA's analysis of the effect of the 
proposed rule on small businesses. The opposing commenters included 
aircraft operators, industry associations, and individuals.
    In the three remaining comments, one individual commenter offered a 
specific language change to the proposed rule without stating support 
or opposition to the rest of it. The other two comments were joint 
submissions from four members of the U.S. House of Representatives that 
expressed strong support for the use of deployable recorder systems.

B. Proposed Retrofits for Part 91 and Part 135 Aircraft

    Two parts of the proposed rule would affect aircraft currently 
operating under parts 91 and 135 by requiring equipment retrofits. 
These include the requirements that CVRs use solid state memory 
(replacing magnetic tape) and have two hours of recording capability, 
up from as little as 15 minutes in part 91.
    The National Air Transportation Association (NATA) expressed 
disappointment with what it considers the agency's failure to include a 
meaningful review of the impact of these two proposed requirements on 
part 91 and part 135 operators. The NATA provided examples of aircraft 
models it does not believe were considered, as well as the types of 
information that the association asserts should have been collected by 
the FAA for analysis. The NATA suggested itself as a source of the 
data, but did not include with its comment any of the data it suggested 
the FAA collect.
    The National Business Aviation Association (NBAA) submitted a 
similar comment, indicating that a broad segment of on-demand operators 
would have to comply with the proposed regulations, but that there was 
no indication that we properly evaluated their effect on those 
operators. As an example, the NBAA noted that the cost of development 
of a supplemental type certificate that would be needed for more than 
15,000 aircraft was not determined or accounted for in the regulatory 
evaluation.
    Similarly, the Regional Airline Association (RAA) said that the 
regulatory evaluation does not adequately describe the benefits of the 
proposed equipment retrofit, and does not feel that there is enough 
information in the regulatory evaluation for them to comment on 
adequately.
    These associations urged the FAA to retract those parts of the rule 
that affect these operators, or to take no further action until more 
comprehensive data can be gathered and analyzed. Each commenter 
believes that the cost estimates would be significantly higher than 
those presented in the NPRM.
    We reviewed our analysis of the impact of the two CVR changes 
proposed as retrofits for part 91 and 135 airplanes (2-hour recorders 
and independent power supply), and we have concluded that our 
regulatory evaluation did not include several issues raised by the 
commenters. Since we are not able to quantify the potential burden of 
the two CVR retrofit requirements on these operators, we have removed 
the two CVR requirements from the final rule for aircraft operating 
under parts 91 and 135. For other reasons discussed below, we are also 
not adopting the proposed `checklist to checklist' language for part 91 
or part 135. New applicability sections will retain the same checklist 
language as exists in the affected part.
    However, we are adopting the datalink recording requirement for 
these two operating parts. If an operator of an aircraft under part 91 
or 135 voluntarily installs datalink equipment after two years from the 
effective date of the rule, the requirement for datalink recordation 
will apply. This is consistent with the requirement facing operators 
under parts 121 and 125, and we have no

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reason to discriminate between these operating rules. We are also 
adopting the requirement for separate containers for CVRs and DFDRs 
(except for rotorcraft) as it imposes no cost since it is a 
codification of current FAA policy and no combined recorder has ever 
been approved for installation on an airplane.
    The NPRM also contained several other requirements that will affect 
only newly manufactured airplanes that may operate under parts 91 and 
135. The commenters provided no reason why those upgrades that must be 
incorporated at the time of aircraft manufacture should not be 
applicable to all categories of aircraft regardless of the eventual 
operator. In general, the proposed CVR and DFDR upgrades on wiring, 
data rates, and interphone communications will be adopted as proposed 
for all newly manufactured aircraft. Similarly, the CVR requirements 
for 2-hour solid state recorders and the addition of a backup power 
system will remain for all newly manufactured aircraft. Again, we are 
unable to draw a distinction between the eventual operating regulations 
for aircraft of any size that have yet to be manufactured.

C. CVR Recording Duration

    The FAA proposed that all CVRs be able to retain the last two hours 
of cockpit audio. Both the NTSB and the Transportation Safety Board of 
Canada noted that the short duration of available cockpit audio 
hindered the investigation of several accidents.
    The Air Line Pilots Association (ALPA) did not support the proposal 
to increase CVR recording time because the FAA did not propose any 
increase in the privacy protections regarding the access and use of 
information recorded on a CVR. The ALPA stated that existing 
protections are inadequate despite years of its attempts to change the 
standard.
    We recognize that ALPA and others have concerns about the use of 
CVR data, and we continue to work to address these concerns. We are 
unable to concur with the conclusion that those concerns outweigh the 
investigative need for more information, especially when it is so 
readily available and affordable. The history of accident investigation 
contains several examples of CVR recordings that begin well into a 
conversation of the problem under investigation. The adverse effect on 
safety of these abbreviated recordings cannot be ignored.
    Boeing Commercial Airplanes (Boeing) agreed that the additional 
data from a longer duration recorder would have been a significant 
benefit in accident investigation. Boeing notes that the proposed 
requirement for part 129 airplanes, however, does not specify a 
recording duration, which it noted may have been an omission.
    The language we proposed for Sec.  129.22 (now Sec.  129.24) would 
require the CVR on a U.S. registered airplane to record the information 
that would be required to be recorded if the aircraft were operated 
under part 121, 125, or 135. This requirement captures the proposed 
requirement in those parts for two hours of CVR recording time. No 
change to the final rule is necessary for the two-hour duration to 
apply to part 129 airplanes.
    In addition to its comment on the economic value of the retrofit, 
the RAA questioned the value of a two hour recorder on flights that are 
on average much shorter. Since many of the RAA's constituents operate 
flights of less than 60 minutes, the RAA stated that the current 30 
minute recording time is sufficient to capture relevant voice data.
    Although we agreed with the commenters concerning the evaluation of 
retrofit costs, the FAA cannot agree that a different standard should 
apply to certain aircraft when they are in regional operation. The 
benefit of this additional information is the same regardless of 
individual flight duration. Further, aircraft transfer between routes 
and operating parts, and none of the aircraft cited by the RAA are 
limited by design to flights of 30 minutes or less.
    Smiths Aerospace, LLC (Smiths) commented that the standard proposed 
in the final rule for CVRs, TSO-C123a, mirrors the standard set forth 
in EUROCAE document ED-56, which allows for the combined (merged) 
recording of three non-area microphone signals into a single recording 
after the first 30 minutes. Smiths suggested that allowing combined 
audio for 90 of the proposed 120 minutes will reduce the quality and 
effectiveness of the recording. Smiths also proposed language that 
would specifically prohibit the use of magnetic tape recorders, since 
it was the agency's stated intent in the NPRM.
    While an interesting technical consideration, the FAA did not 
propose a change to the TSO standard (which is based on ED-56) in the 
NPRM, and the process for changing TSOs is separate and complex. We 
also believe that a requirement for two hours of recording time is 
enough to eliminate the use of magnetic tape recorders for those 
aircraft subject to the requirement. Further, Smiths did not indicate 
where this language would be inserted, and a change in the retrofit 
applicability for parts 91 and 135 would simply add to the confusion 
about current requirements.
    No change to the 2-hour recording duration has been made in the 
final rule based on these comments.

D. CVR Independent Power Supply

    Seven commenters (ALPA, Boeing, Smiths, the NTSB, the Aerospace 
Industries Association (AIA), Radiant Power Corporation (Radiant) and 
Airbus) expressed concern that the proposed requirement for a Recorder 
Independent Power Supply (RIPS) for CVRs did not address installation 
issues. These commenters want to minimize the possibility of an 
inadvertent disconnect from the CVR that could result from damage to 
the RIPS or to exposed, lengthy wiring. These commenters suggested 
several installation solutions, including:
     Installing a combination kit of the CVR plus the RIPS 
(AIA), or integrating the RIPS in the CVR (Airbus, Radiant, Smiths); 
and
     Co-locating the CVR and the RIPS (ALPA) or locating the 
RIPS as close as practical to the CVR (Airbus, Boeing, NTSB).
    The FAA agrees with the concern raised by these commenters. We have 
considered the various installation solutions suggested by the 
commenters, and have determined that requiring the RIPS to be installed 
as close as practicable to the CVR is the best solution. This 
configuration will minimize the distance between the CVR and the RIPS 
and the amount of wiring necessary, decreasing the potential for a 
power failure affecting the CVR when main power is lost and the RIPS 
unit engages. Therefore, the final rule contains a requirement that the 
RIPS be installed as close as practicable to the CVR.
    As to the integration of the RIPS into the CVR unit, we do not have 
enough data to support either mandating or prohibiting a combined RIPS/
CVR unit. The decision to combine the units is best left to the system 
designer for individual aircraft. Our TSO-C155 and other industry 
standards allow for certification of RIPS as either a combined or 
stand-alone unit. Combined units would meet the ``as close as 
practicable'' standard of the regulation.
    Boeing noted the term ``independent'' could be interpreted to mean 
the RIPS must be a separate piece of equipment and cannot be 
incorporated into the CVR. Boeing suggested adding a new subparagraph 
to Sec.  25.1457 that would allow, but does not require, incorporation 
of the RIPS as part of the CVR.

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    As stated, the purpose of the RIPS equipment is to ensure the CVR 
continues to function for 10 minutes following the loss of its main 
power source by having its own independent power source. The term 
``independent'' does not describe the location of the RIPS as it 
relates to the CVR. In TSO-C155, we state that the RIPS may be a part 
of the CVR or separate from it.
    Five commenters (AIA, ALPA, Boeing, L3 Communications (L3) and the 
NTSB) suggested the final rule should contain a 4-year retrofit RIPS 
requirement similar to that proposed for the 30-minute-to-2-hour CVR 
conversion. The NTSB stated the benefits of such a requirement vastly 
outweigh the additional costs. Boeing agreed, stating that a RIPS 
retrofit would have significant value for in-service aircraft. The ALPA 
and AIA support a RIPS retrofit requirement for all aircraft operating 
under part 121, while L3 noted that it had anticipated the need for 
such equipment, and that their product development is complete and 
represents an available, cost-effective solution.
    While the FAA recognizes the benefits of expanding the RIPS 
requirement beyond newly manufactured aircraft, we remain unable to 
mandate retrofit as a cost-beneficial change. When we considered the 
option for the NPRM, we found that the cost of a RIPS retrofit was 
considerable and the burden on current operators would be substantial. 
Even if the equipment is already available, a RIPS retrofit could 
easily require major alterations and extensive aircraft rework. While 
expressing their support, the commenters did not provide any data that 
changes our conclusion.

E. RIPS on Rotorcraft

    Three commenters, Bell Helicopter Textron Inc. (Bell), Eurocopter 
Deutschland GmbH (Eurocopter) and the Helicopter Association 
International (HAI), recommended the RIPS requirement not apply to part 
27 and 29 rotorcraft. Bell stated the NPRM failed to make a case for 
small to medium rotorcraft (fewer than 20 passengers) and noted that 
these aircraft are much less likely to suffer the types of events and 
failures that occur in fixed wing aircraft.
    Eurocopter stated that a RIPS requirement is not relevant for 
rotorcraft for two reasons, first citing three EUROCAE documents that 
forbid shutdown of a CVR by the crew. Second, when the CVR is already 
powered by the safest electrical power bus, a RIPS would not decrease 
the probability of a failure, but would add substantial installation 
and annual costs.
    The lack of historical data supporting a need for RIPS for CVRs in 
rotorcraft was also cited by HAI. It noted that the proposed rule is 
directed at transport category airplanes, where RIPS can be justified, 
but does not make the case for small to medium rotorcraft certificated 
under part 27 or part 29. The HAI stated that the increase in system 
weight, cost and complexity would provide little or no enhancement to 
safety.
    As a consequence of the proposed RIPS installation, Columbia 
Helicopters, Inc. (Columbia) asked the FAA to consider possible 
unwanted consequences on helicopters operating under part 133 external 
load operation (non-passenger carrying) rules. Columbia noted that the 
added weight and operating cost of a RIPS might discourage these 
operators from voluntarily installing CVRs. Columbia suggested language 
limiting the RIPS requirement to passenger carrying operations.
    The final rule includes part 27 and 29 rotorcraft with fewer than 
20 passengers in the RIPS requirement, as proposed. The purpose of the 
RIPS requirement is to record additional pilot communications, 
environmental noises and other information (such as from a cockpit-
mounted area microphone) if all power is lost. A loss of power is 
possible on aircraft of all types. We are unable to distinguish 
rotorcraft from other aircraft when the possibility of power loss is 
considered, and the benefits are considered the same. We do not require 
compliance with EUROCAE standards; our regulations must reflect our 
requirements.
    The FAA does not agree the RIPS requirement might discourage part 
133 operators from voluntarily installing CVRs. The RIPS requirement is 
for newly manufactured aircraft whose operating rules require a CVR. 
There is no mandated RIPS retrofit if a CVR is installed on an aircraft 
that does not require one for operation.
    The CVR and RIPS TSOs provide the minimum performance standards for 
this equipment. However, neither one requires that RIPS be installed; 
that is done by regulation. If a part 133 operator voluntarily chooses 
to install a CVR, it is not currently required to also install the 
RIPS, nor is the operator prevented from installing a RIPS. This 
decision is totally up to the part 133 operator. Therefore, we do not 
agree with the commenter that adding the RIPS requirement to parts 27 
and 29 would affect the decision to voluntarily install a CVR.

F. RIPS Duration Requirement

    Three commenters (Boeing and two individuals) requested that the 
FAA change the duration of the RIPS power requirement. Boeing requested 
that the requirement be changed from 10 minutes to 101 
minutes, to prevent erasure or overwriting of valuable data, and to be 
consistent with TSO C-155 for RIPS, and other industry standards from 
EUROCAE's ED-112 (Minimum Operational Performance Specification for 
Crash Protected Airborne Recorder Systems) and ARINC 777 (Recorder 
Independent Power Supply). If adopted, Boeing suggested that the final 
rule state that the ``101 minutes'' means the backup power 
source must operate at least 9 minutes, but not longer than 11 minutes.
    One individual commenter suggested increasing the time to 30 
minutes because 10 minutes is too short a time period to record 
everything during a power failure. The commenter provided no details or 
examples of the need for 30 minutes. A second individual stated that 
the 10-minute standard is insufficient, but did not specify what the 
duration should be.
    The FAA agrees with Boeing that the final rule should be consistent 
with the TSO and industry standards. The final rule requires the RIPS 
to provide 101 minutes of electrical power to operate both 
the cockpit voice recorder and cockpit area microphone. We are not 
including the additional suggested language since the documents cited 
by Boeing establish that 101 minutes means the backup power 
source shall run at least 9 minutes, but not longer than 11 minutes, 
and repetition of the language is not necessary.
    The other commenters did not explain why the international standard 
of 10 minutes is not appropriate nor provide any other support for 
their positions.

G. Other RIPS Issues

    Airbus stated that two years is not enough time to integrate a RIPS 
into current aircraft designs. Airbus stated that TSO-C155 requires 
that a RIPS system provide both a failure monitoring function and 
indications to the flightcrew. Airbus requested that the compliance 
time be changed to four years, to account for the modifications, 
qualification and certification of RIPS equipment.
    We agree that RIPS installation on newly manufactured aircraft will 
require integration into the existing warning and indication systems. 
However, Airbus did not provide us with any specific data to support 
its position that this requirement could not

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be accomplished two years after this final rule. Further, no other 
airframe manufacturer expressed this concern. The 2-year compliance 
date for the installation of RIPS into newly manufactured airplanes is 
adopted as proposed.
    Airbus and Boeing each noted that the CVR may also provide power 
for the cockpit area microphone and associated electronics, such as a 
preamplifier. Since the proposed RIPS requirement only applies to the 
CVR, they expressed concern that the additional equipment may not be 
powered and would render the CVR useless despite its own power. Each 
commenter suggested that language be added to Sec.  25.1457 that 
addresses a continuation of power to all parts of the CVR system 
required for recording area microphone audio input.
    The FAA agrees with Boeing and Airbus. In addition to the reference 
for 101 minutes of electrical power discussed above, the 
regulation has been changed to include power to operate both the 
cockpit voice recorder and the cockpit-mounted area microphone.
    AirTran Airways (AirTran) requested that any RIPS requirement 
ensure CVR interchangeability so that operators will not have to 
maintain separate CVR inventories for aircraft that have the RIPS and 
those that do not.
    While we recognize that CVR interchangeability is desirable, the 
type of CVR (and RIPS) on a given aircraft is driven by installation 
and component design, not by regulation. The CVR and RIPS each have a 
TSO (as well as ARINC standards) that will ensure that as long as an 
operator uses these components, interchangeability should not be an 
issue. AirTran and other operators need to provide input to the 
manufacturers of airframes and CVRs during the development of RIPS 
equipment. The final rule does not address CVR interchangeability.

H. CVR and DFDR Wiring Requirements

1. Single Electrical Failure
    We proposed that CVRs and DFDRs be installed so that no single 
electrical failure could disable the recorders.
    Bell requested the FAA exclude part 27 and part 29 rotorcraft with 
fewer than 20 passengers from the requirement that no single electrical 
failure will disable both the CVR and DFDR. Bell referred to historical 
data presented by the United Kingdom Aircraft Accident Investigation 
Board (AAIB) and Bell's own experience with combined recorders, to 
conclude that this requirement is unnecessary and would result in 
significant development and certification costs.
    Bell also stated that the ``no single electrical failure could 
disable both the CVR and DFDR'' language was ambiguous. Bell noted that 
it has been interpreted in different ways, and that if it is applied to 
either the failure of any single electrical component within a combined 
CVR/DFDR, or to a single electrical failure external to the recorder, 
it would make most available recorders obsolete. Bell suggested that if 
the applicability to all rotorcraft is maintained, the language be 
changed to indicate that the single electrical failure at issue is 
external to the recorder.
    Columbia Helicopters made a similar argument, noting that for an 
allowed combined recorder, the requirement is confusing and 
contradictory, and requested that the language be clarified.
    The FAA acknowledges that the separation of electrical power has 
not been an issue on rotorcraft to date. However, the potential problem 
being addressed by the ``no single electrical failure'' requirement 
remains in any tiered electrical power system and may affect all 
aircraft, fixed wing or rotorcraft. We also agree that the language of 
the proposed requirement could be misinterpreted in a combined recorder 
installation. Since the intent of the regulation is to prevent 
electrical failures of aircraft wiring or electrical power external to 
the recorder from disabling both recorder functions, we have changed 
Sec. Sec.  23.1457(d)(4), 25.1459(a)(7), 27.1457(d)(4) and 
29.1459(a)(6) to reflect this interpretation. However, we remain unable 
to distinguish rotorcraft by the number of passengers, and the rule is 
adopted for all helicopters with the modifications described here.
    The NTSB and the AIA recommended the no single electrical failure 
requirement be expanded beyond newly manufactured aircraft to include 
the existing fleet. The NTSB noted that, with this change, the final 
rule would comply with the NTSB recommendation on this subject. The 
NTSB also stated that since most existing aircraft already meet this 
requirement, any retrofit requirement would have a minimal economic 
impact. The AIA suggested the FAA consider including the current fleet 
after conducting a cost-benefit analysis.
    The FAA considered this option while developing the NPRM and found 
that a wiring retrofit represents a significant economic burden, and 
could require extensive aircraft rework in order to rewire not only the 
recorder systems, but other aircraft systems that are affected by 
changes made for the recorders. The commenters did not provide any new 
data for either the costs or benefits that would change our conclusion. 
The final rule remains applicable only to aircraft manufactured two 
years after this final rule.
2. Single Electrical Failure vs. Most Reliable Bus
    In addition to the requirement that no single electrical failure 
disable both recorders discussed above, we proposed that all newly 
manufactured aircraft have a CVR and DFDR installed that receives its 
electrical power from the bus that provides the maximum reliability of 
operation.
    AirTran and Northwest Airlines (Northwest) suggested the proposed 
language for these two requirements is contradictory. AirTran stated 
that, in order to have the DFDR and CVR on different sources to 
preclude a single failure from disabling both units, one of the units 
is likely to be on a less reliable source than the other. Northwest 
asked if requiring both the CVR and FDR to be powered by the most 
reliable bus would create an opportunity for a single point electrical 
failure that disabled both recorders, violating the single failure 
proposal.
    We disagree that the two requirements are contradictory. Proper 
system design will allow the CVR and the FDR to be powered by 
different, but equally reliable, buses. This will ensure that a single 
point failure does not affect both. We recognize that some sensors in 
the DFDR system may be powered by buses that are lower in the 
electrical hierarchy than the recorders. While some information may be 
lost if these lower buses fail, the failure itself could provide 
insight as to the sequence of events occurring during an accident or 
incident and does not create an issue with the failure of power to the 
recorder itself.
3. Most Reliable Bus--Other Comments
    The ATA expressed concern that the proposed language regarding 
power to the recorders from the most reliable bus (Sec. Sec.  
25.1457(d)(1) and 25.1459(a)(3)) is vague, and proposed different 
language for these sections. Northwest expressed the concern that the 
last sentence in each paragraph is redundant and suggested the proposed 
language is redundant with the existing paragraph.
    We have reviewed the proposed language and have concluded it 
properly conveys the intent of the requirements. The language suggested 
by the ATA introduces terms that would be open to numerous 
interpretations, and suggests a requirement for recorder power much 
more restrictive than our intent.

[[Page 12547]]

    Regarding Northwest's comment that the second sentence in each 
paragraph is redundant, we note that, while similar, they address two 
separate issues. The first sentence addresses the source of the 
recorder's power (i.e., the bus). The second sentence addresses the 
situation experienced during Swissair flight 111, in which the 
flightcrew disabled the electric bus that powered both the CVR and the 
DFDR while searching for a source of smoke in the cockpit.
    Smiths suggested that all CVRs on newly manufactured aircraft 
provide dual isolated power bus inputs to provide the recorders with 
the most reliable and available power and reduce the possibility of a 
single electrical failure disabling a recorder.
    We reviewed Smiths' proposal, but the commenter did not provide any 
information comparing its suggestion to the proposed rule, any 
suggestion of the extent to which it might be used, or the cost of such 
a requirement. We concluded that our proposal to require the DFDR and 
the CVR to be powered by separate buses is sufficient and is 
performance-based.

I. Separate Containers

    Boeing noted the proposal stated that each separate container must 
meet the ``crashworthiness requirements already in the regulations.'' 
Boeing assumed this statement refers to Sec. Sec.  25.1457(e) and 
25.1459(b) and requested clarification.
    The phrase ``crashworthiness requirements already in the 
regulations'' refers to the existing requirements in parts 91, 121, 125 
and 135 for installing recorders (both CVR and DFDR) that meet the 
crashworthiness requirements of TSO-C123a or TSO-C124a.
    Columbia sought clarification on the applicability of the proposed 
requirements of Sec. Sec.  27.1459 and 29.1459. Columbia interpreted 
the proposal to require all helicopters currently equipped with 
combination recorders to meet the entirety of the certification 
sections cited four years after the adoption of the final rule, which 
would require a retrofit of several items, including the 10 minute 
RIPS. Columbia suggested this interpretation did not reflect the intent 
of the FAA and recommended rewording the rule to remove any confusion.
    We believe the commenter is misreading the proposal. Columbia 
referred to ``proposed 135.152(1),'' but that is not a valid reference. 
Proposed Sec.  135.152(l) (lower case ``L'') addresses only the 
recorder containers, and means that part 23 and 25 airplanes must 
maintain the recorders in two separate boxes, while part 27 and 29 
rotorcraft may have one combined unit. A combined unit must meet all of 
the requirements for both DFDRs and CVRs, which are determined by 
aircraft age.
    The other DFDR and CVR requirements are mandated in Sec.  
135.152(m)(1), which applies to aircraft manufactured two years after 
the rule, and repeats the new container reference; there is no retrofit 
requirement for the other certification sections referring to wiring if 
the installation is not altered. On this topic, the commenter may also 
have been confused by the discussion in the preamble of the proposed 
rule, which indicates that if a rotorcraft operator changes a current 
two-unit installation to a single combined unit, the new power and 
wiring requirements must be met. Since a single combined unit is 
optional, the rule does not impose the new wiring requirements unless 
the operator chooses to make the change, and the operator must consider 
the cost of the rewiring as part of its decision to change to a single 
combined unit.

J. Dual Combination Recorders

    When the NTSB recommended the installation of two full recording 
systems, it was included as part of a much larger system 
recommendation. The NTSB suggested that each aircraft have a system 
that included two combination recorders, one fore and one aft, with a 
RIPS attached to the forward combination recorder. The NTSB recommended 
this as a retrofit.
    We did not propose the installation of two full sets of recording 
equipment, referred to as ``dual combination recorders,'' as 
recommended by the NTSB because of the substantial costs involved. We 
did propose that a RIPS be installed for the CVRs on newly manufactured 
airplanes.
    Several commenters, including Airbus, ALPA, Boeing, Embraer, 
Honeywell, Smiths, and the NTSB, each suggested some variation on our 
allowing the use of combination recorders. In a related issue, three 
individual commenters recommended placing the CVR and DFDR in separate 
parts of the aircraft to increase the chances of survival. The 
commenters raised issues of cost, survivability, separate location, and 
redundancy in arguing for combination recorders.
    Generally, if two combination recorders are installed, one would be 
designated as the DFDR and one as the CVR in accordance with the 
separate container requirement. As a follow-on to this configuration, 
several commenters requested that one combination recorder be located 
at the front of the airplane to act as the CVR.
    These suggestions bring up several issues when one or more 
combination recorders are installed, including non-functioning 
equipment for Minimum Equipment List (MEL) relief, RIPS units, and the 
regulations on recorder location and separate containers.
    Accordingly, the FAA is revising the regulations to allow for the 
following in the final rule:
    (1) When a single combination recorder is used in place of either a 
DFDR or a CVR, it will only be allowed to function as the chosen unit. 
The combination recorder and the single function recorder must maintain 
the requirements for aft location and separate boxes. No relief from 
any regulation is granted by this configuration. If one combination box 
is used, it cannot be used as a CVR located near the cockpit.
    (2) When two combination recorders are used, one may be located 
near the cockpit. This recorder will function as the CVR and, in newly 
manufactured airplanes, may be co-located with the RIPS. In the event 
of an equipment failure subject to relief under an operator's MEL, no 
further relief is given than for separate units.
    The FAA does not consider the voluntary installation of two 
combination recorders to be the redundant/dual system envisioned by the 
NTSB recommendation. The use of two combination recorders is not 
mandated for any installation. Single-purpose recorders are the 
regulatory minimum, and when used, all of the requirements including 
separate containers, wiring, and aft location remain the same.

K. Increased DFDR Recording Rates

1. Need for 16 Hertz (Hz) Requirement
    The FAA proposed an increase in the recording rate to 16 Hz for 
certain flight control parameters on aircraft manufactured two years 
after the final rule. While acknowledging that parameters recorded at 1 
or 2 Hz are inadequate, five commenters, Airbus, AirTran, ATA, Boeing, 
and Embraer, suggested that a 16 Hz recording rate is excessive and 
could be very costly.
    Airbus argued the proposed rate would not only affect the DFDR and 
associated interface units, but would also require redesign of the 
aircraft's systems providing the parameter data. Airbus stated the 
impact of such a redesign is not covered in the compliance cost 
estimates in the NPRM, nor is the proposed 2-year time frame realistic 
for a redesign of these systems. Therefore, Airbus recommended 
replacing the existing standard with a

[[Page 12548]]

sampling rate appropriate to a given aircraft type and supplied rates 
for each of its aircraft models. Airbus's comment does not include 
information on how the FAA would decide which rate is appropriate for 
any given aircraft, or how such a standard could be established or its 
estimated cost for each model aircraft.
    AirTran noted the proposed sampling rate for each flight control 
unit (nine total) would exceed the capacity of the DFDR system 
installed in its fleet. AirTran recommended a sampling rate equal to 
the recording capacity of the DFDR systems. For AirTran's installed 
DFDR systems, this capacity is roughly 8 Hz.
    The ATA noted that some in-production aircraft do not provide data 
at the 16 Hz rate. These aircraft would require an extensive and costly 
redesign to keep component interchangeability. Therefore, ATA proposed 
changing the 16 Hz recording rate to a recording rate requirement that 
is ``at a maximum rate available from that aircraft system up to 16 
Hz.''
    Boeing stated that 16 Hz is not necessary if the goal is to make 
the recorded control motions unambiguous. Instead, a change to 16 Hz 
would result in unnecessarily large data analysis files and require 
significant added costs to change the signal source. Boeing recommended 
recording at 4 Hz.
    Embraer suggested the 16 Hz recording rate will require a 
substantial amount of data memory capacity on DFDRs that may not be 
available. This would result in the removal of some recorded parameters 
or installing new DFDRs having more data memory. Embraer proposed the 
FAA require a recording rate of 8 Hz, or the maximum sensor output 
frequency, whichever is less.
    The FAA appreciates the detailed comments received on this subject. 
We have reconsidered the proposal and agree that a 16 Hz recording 
rate, while desirable, is not practicable for most installations. We 
remain convinced that existing recording rates for certain primary 
flight controls are lagging behind available technology and that a 
change is necessary. Therefore, in the final rule, the new recording 
rate is 8 Hz for specified parameters on aircraft manufactured two 
years after this final rule. This rate will sufficiently increase the 
reliability of the data received and will not require any modifications 
to the systems that provide the parameter data to the DFDR system. For 
some newly manufactured airplanes, additional recorder capacity may be 
required, but the source equipment will remain as is installed today.
    Boeing recommended that the final rule prohibit interleaving, since 
that practice impacts the true sampling rate. Interleaving is the 
practice of sampling inputs and combining those samples to comply with 
sampling rate requirements. For example, if the left elevator position 
is recorded two times per second, and the right elevator two times per 
second, the total of these two measurements are combined to derive a 
sampling rate of four times per second. This practice was originally 
necessary to meet the sampling rate requirements on DFDR systems with 
smaller memory capacity. This practice is undesirable because, in 
reality, alternating the inputs only provides data at the lower rate 
for each interleaved position. In some cases, such as for inboard and 
outboard aileron surface positions, the inboard surface is locked out 
under certain flight conditions. When the parameters from these 
surfaces are interleaved, the result is no data for half of the 
samples.
    We agree with Boeing and have changed the language of the final 
rule to state that alternately sampling inputs to meet the applicable 
sampling interval is not permitted. The prohibition on interleaving 
applies to those flight control parameters subject to footnote 20 to 
part 121 Appendix M (and its equivalent in other operating parts).
2. 16 Hz Requirement--Applicability
    Four commenters (Bombardier, Dassault, Embraer and Honeywell) 
recommended that any requirement to increase sampling rates apply only 
to new aircraft type certification programs, rather than newly 
manufactured aircraft.
    Bombardier noted that a sampling interval of 0.0625 seconds (16 Hz) 
would require a major redesign of existing equipment from the data 
source through data concentrator units to the FDR. None of the current 
equipment on Bombardier's products was designed to process data at 16 
Hz. Bombardier contended the cost estimates in the NPRM severely 
underestimated the equipment redesign costs and the subsequent test and 
certification costs. These extensive changes would require more than 
two years to develop and certify.
    Dassault stated the proposed 16 Hz requirement could require a 
complete electrical and mechanical modification, and result in a 
recertification of the entire DFDR installation. In addition, Dassault 
noted that a 16 Hz sampling rate is too high for flight controls and 
adds no value.
    Embraer stated that, on some of its airplanes, neither the force 
sensors for the flight controls nor the data acquisition systems can 
support the proposed sample rate of 16 Hz, and would require new 
equipment. Embraer recommended a lower sample rate (8 Hz), and proposed 
that a 16 Hz sample rate apply to new aircraft type certification 
programs only.
    Honeywell noted that, for aircraft in production, any increase in 
the sampling rate of a control surface position or a control input 
would require a change to the systems that provide source data to the 
DFDR system. Honeywell also stated that a sampling rate of 16 times per 
second, while reasonable for some parameters, might be burdensome or 
inefficient for others. Honeywell suggested that a performance-based 
standard for recording would be superior to the one proposed, with the 
actual rate to be established as part of the certification process.
    We are adopting an 8 Hz requirement in the final rule rather than 
the 16 Hz proposed. Based on the comments, we have determined that 8 Hz 
is the maximum rate that can be achieved without requiring modification 
of the systems and equipment that provide individual parameter data to 
the DFDR system. The need for some increase in the sampling rate has 
been addressed in the NTSB recommendations, as well as a study done by 
the FAA and NASA. The study clearly shows that critical control surface 
position data can be lost at the lower sampling rates, and that it is 
true for all aircraft. The final rule requirement for an 8 Hz recording 
rate will apply to all newly manufactured aircraft.
3. 16 Hz Requirement--Other Comments
    The NTSB expressed disappointment that the proposed increase in the 
sampling rate does not address existing aircraft, as called for in NTSB 
Recommendation A-03-49.
    As discussed in the NPRM, the FAA was unable to justify the 
substantial economic burden that would be imposed on current operators 
to apply this as a retrofit requirement. As detailed by the commenters, 
it is anticipated that it could be a significant burden to incorporate 
into newly manufactured aircraft, much less as a retrofit to much older 
aircraft whose recording systems and source equipment are not equipped 
to record at the higher proposed rate. While we recognize the benefits 
of increasing the sampling rates of flight control parameters on 
existing aircraft, we are unable to quantify that benefit or balance it 
against the costs. The NTSB

[[Page 12549]]

has not provided us with data that would change this conclusion.
    An individual commented that the proposed language ``the sampling 
interval per second is 16'' for footnote 5 of Appendix E to part 91 is 
ambiguous. The commenter recommended changing this to ``the minimum 
sampling rate is 16 samples per second'' or ``the maximum sampling 
interval is .0625 second.''
    The proposed language is consistent with industry practice and the 
footnotes already in Appendix E to part 91 and the other applicable 
flight recorder appendices that have been in use for years. No change 
was made based on this comment.

L. 25-Hour Recorder

    Eurocopter stated the proposed increased duration for DFDR 
recording in Sec.  91.609(c)(3) (25 hours) should not be applied to 
rotorcraft, based on its experience that rotorcraft missions do not 
exceed 10 hours.
    Based on its experience in investigating aircraft accidents and 
incidents, the NTSB determined that an FDR duration of 25 hours would 
address many of the issues it has faced. The FAA has chosen to make the 
25-hour DFDR recording retention standard for all new aircraft. As the 
commenter noted, increased recording time is a matter of memory, and is 
not a technical challenge. While we acknowledge Eurocopter's suggestion 
that regulations for fixed-wing aircraft and rotorcraft might have 
different goals, we believe that the issue of recording time should be 
maintained as a standard regardless of aircraft type. We have no data 
to suggest that recording time needs be specific to aircraft type or 
operation, and believe that standardization makes the regulations less 
complicated and less expensive by using the same available equipment.

M. Datalink Communication (DLC)

1. International Compatibility
    Three commenters, Airbus, Boeing and an individual, noted that the 
Joint Aviation Authorities (JAA) is also preparing a regulation on DLC 
recording and requested that the FAA ensure the U.S. regulations are 
harmonized with the JAA's. They expressed concern that as proposed, the 
regulations are incompatible.
    The FAA believes the proposed DLC recording regulation is 
compatible with the DLC regulations proposed by the JAA. The proposed 
rule is designed to be performance-based, with the message set to be 
recorded and approved at the time of aircraft certification. Since we 
do not define the message set, we do not foresee an instance in which a 
DLC system certificated under the regulations proposed by the JAA would 
not be in compliance with our requirement as proposed.
    In response to the JAA's Notice of Proposed Amendment (NPA), the 
FAA has sent several comments concerning general and specific 
provisions of the proposal. We acknowledge that the two proposals are 
not harmonized, and we believe the scope of the current NPA would 
result in significant costs on some operators without a resulting 
safety benefit. We have asked that several technical issues be 
clarified, including parts of ED-112 and whether the regulation would 
apply to aircraft with ACARS only. We will continue working with the 
JAA (and the European Aviation Safety Agency (EASA) when it assumes 
responsibility for this issue from the JAA) to make the regulations 
more compatible but will not delay the issuance of this rule since our 
rule is more performance-based and less dependent on the resolution of 
individual technical issues.
    The International Air Transport Association (IATA) stated that 
before the United States proposes a DLC recording requirement, the 
International Civil Aviation Organization (ICAO) should take the lead 
to substantiate the datalink recording requirements and provide clear 
guidance on the data that needs to be recorded (including its relevance 
to accident investigation). The IATA stated that industry cannot 
address the desired architecture for all aircraft types until these two 
issues are resolved.
    Since no specific message set is required, we consider our 
regulation to be adaptable to ICAO or the JAA's proposed requirements 
at the time an aircraft is certificated. We do not believe it is in 
anyone's interest to wait for another international standard to be 
settled before recording is required, and we built the described 
flexibility into our standard.
2. Definitions of DLCs and Approved Message Sets
    Thirteen commenters addressed the issue of what DLCs should be 
recorded and what would constitute an approved message set. These 
commenters criticized the proposed requirement to record ``all datalink 
communications'' as open to interpretation, ambiguous and poorly 
defined. These commenters sought clarification and requested that clear 
guidance material be available when the final rule is published. A 
sampling of the comments on DLC message sets includes suggestions to:
     Record ``flight deck datalink communications'' rather than 
``all'' to eliminate the recording of navigation, surveillance and 
maintenance, and cabin and passenger communications.
     Not require the recording of flight deck crew interaction, 
including cabin terminal messages, maintenance computer messages, 
engine condition monitoring messages, or atmosphere/wind reports.
     Limit recording to communications between aircraft and air 
traffic control via the air traffic network.
     Record all DLCs sent and received regardless of their 
content or format, or whether they are ``approved message sets;'' this 
would be the least restrictive to implement and provide the most 
information to investigators.
     Place the definition of ``approved data message set'' in 
part 121 (and parts 91, 125 and 135 as appropriate), similar to the 
current FDR parameters.
     Make the definition of approved message sets flexible to 
respond to changes in technology, such as higher bandwidth.
    The types of messages and the content of those messages that will 
be recorded will be determined during certification of the DLC system. 
The rule language is performance-based, with the intent that system 
design would be driven by customer needs and regulatory compliance. The 
``approved message set'' will be comprised of the messages provided by 
the system being installed, and will be determined by certification 
personnel. Concurrent with the publication of this rule, we are 
publishing a Notice of Availability of Advisory Circular, AC 20-160. 
The AC identifies Controller-Pilot Datalink Communications (CPDLC) as 
one set of messages that are anticipated to be included in the required 
message set. An example of a CPDLC message set can also be found in 
ICAO Document 4444 ``Air Traffic Management Procedures for Air 
Navigation Services'', Appendix 5. However, we anticipate that as new 
datalink systems and capabilities are developed, the message sets of 
that equipment will evolve and will need to be evaluated to determine 
which parts need to be recorded to comply with the regulations. A rule 
that requires approval at certification anticipates this evolution 
without creating regulatory lists that cannot be changed as quickly as 
the technology develops and thus hinders system evolution and 
improvements.
3. Compliance Time
    The NTSB objected to the proposed requirement to record DLCs two 
years after datalink equipment is installed.

[[Page 12550]]

The NTSB failed to see the reason for the delay when the installed 
communications equipment should have the capability of outputting the 
required datalink messages to the voice recorder at the time of 
installation.
    The NTSB's interpretation of the proposed requirement is incorrect. 
The requirement is to record DLCs on any aircraft on which DLC 
equipment is voluntarily installed beginning two years from the 
effective date of the final rule. For the first two years after the 
effective date of the final rule, DLC equipment can be installed on 
aircraft regardless of whether the messages can be recorded. However, 
beginning two years from the date of the final rule, DLC messages must 
be recorded as of the date of equipment installation or certification, 
whether the equipment is installed as a retrofit or at new 
certification.
    Northwest requested that, for newly manufactured aircraft, the 
compliance date be extended to the 2010-2012 timeframe rather than two 
years after the final rule. Northwest stated that more time is needed 
to approve the different message sets that will be used by air carriers 
and to create the required ground infrastructure.
    While developing the NPRM, the FAA considered the factors listed by 
Northwest, but determined that two years from the effective date of the 
final rule is sufficient for airframe and recorder manufacturers to 
develop compliant systems for the DLC recording requirement, especially 
since installation remains optional. No other comments were received 
indicating this time period is insufficient. We also note that the 
topic has been under consideration internationally for years.
4. Existing DLC Capability
    Japan Air Lines (JAL) requested clarification on the applicability 
to airplanes equipped with DLC equipment before the 2-year date, in 
order to properly estimate the anticipated financial impacts and 
effects on production and maintenance.
    Similarly, AirTran requested the final rule specify that aircraft 
that are DLC-equipment capable, but have never had it fully installed, 
are not subject to the recording requirements. AirTran also requested 
that the recording requirement not apply to airplanes on which DLC is 
installed ``post delivery'' or it will deter installation of DLC 
equipment.
    Boeing stated the regulation should require datalink recording only 
if DLCs are used operationally, rather than if DLC equipment is 
installed, noting that many aircraft have the equipment, but it is not 
enabled or used.
    The requirement for recording DLC is determined when the DLC system 
is installed and certified. If the system is installed and certified 
before April 7, 2010, there is no requirement for those systems to 
record messages. If the DLC system is installed and certified (at 
manufacture or by retrofit) after April 7, 2010, the DLC system must be 
examined to determine whether its message set installed at the time 
must be recorded. The messages that must be recorded become the 
approved message set for that installation. If a provisional (inactive) 
system is installed and certificated before April 7, 2010, and requires 
no further certification when the system is activated, then there is no 
recording requirement for that system even if the activation occurs 
after two years. However, a change in such a system (especially a 
change to the message set being used) may trigger the requirement to 
record as though the whole system were a new installation under the 
regulation.
5. Datalink Recording Requirement Applicability
    Several commenters (ATA, AirTran, Airbus, Boeing and RAA) suggested 
that the applicability of the datalink recording requirement be changed 
or that the requirement be completely withdrawn. The ATA proposed that 
on-board recording of datalink communications ``only apply to new 
(datalink system) installations on aircraft in production.'' Airbus 
concurred with the requirement for newly manufactured aircraft, but 
requested that the requirement for recording messages from newly 
installed systems on existing aircraft be delayed until 2010. The RAA 
requested that ``the proposal to retrofit airplanes for recording 
datalink messages also be withdrawn.'' Boeing commented that ``[T]he 
appropriate point to introduce onboard recording is at a new airplane 
type certification program or, for existing production models, at a 
major upgrade to the next generation of datalink communications, such 
as FANS 2 or equivalent.'' The commenters provided the following 
reasons in support of withdrawing the requirement or changing the 
proposed recording applicability:
     High costs of incorporation would delay and/or prevent the 
installation and use of DLCs, diminishing the safety benefits 
associated with datalink operations, and the benefits of reduced 
separation and increased traffic.
     Incorporation during a new type certification program 
lessens the economic impact by allowing it to be introduced during the 
aircraft design process.
     Most DLC applications are related to air traffic control, 
are still evolving, and are not yet sufficient to replace the aircraft/
controller voice communication entirely or to supplement voice 
communication as planned.
     Current DLC systems cannot support recording functions 
without significant upgrades or re