[Federal Register: March 7, 2008 (Volume 73, Number 46)]
[Rules and Regulations]
[Page 12541-12573]
[DOCID:fr07mr08-16]

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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

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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<PHONE_NUMBER>; facsimile
(202) 385-4651; e-mail<EMAIL_ADDRESS>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<PHONE_NUMBER>; facsimile (202) 267-
3073; e-mail<EMAIL_ADDRESS>
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

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

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.

    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

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.

    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

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

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.

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 replacement with newer systems. The
aircraft modifications required would significantly exceed the expenses
for changing the CVR and wiring only.
    The FAA recognizes these concerns, but we continue to believe that
the two year applicability in the rule provides the best balance of
compliance time and technological development. If an operator cannot
justify the expense of a recording system for a new DLC installation,
then it is because the benefits of having the system will be
outweighed. This is why we tied the requirement to the voluntary
installation of DLC systems. The recording requirement remains the same
as proposed--that new installations (at certification or on retrofit)
of datalink accomplished two years after the compliance date must be
recorded.
6. Technical Issues
    An individual commenter questioned the amount of memory needed to
meet the two-hour DLC recording requirement. This commenter noted the
amount of data that could theoretically be received in two hours will
increase as developments in DLCs are deployed. Therefore, an agreed
methodology (for formatting and storing messages in memory) will be
needed to support certification.
    Smiths concurred with the proposed rule, and noted the capacity of
DLCs to be recorded is dependent on the aircraft system design (such as
an ARINC 429 databus or AFDX network). Smiths expressed concern that
too many messages to be recorded could exceed the capacity of the
allocated 2-hour recording partition.
    To meet current recorder requirements, recorder manufacturers have
developed procedures to calculate the necessary memory requirements
depending on system design and installation. Therefore, the FAA has no
reason to believe these manufacturers will be unable to determine the
amount of memory needed to meet the two-hour DLC recording requirement.
    The NTSB noted that adding a properly placed cockpit video camera
would allow DLCs displayed to the crew to be recorded on the video
image

recorder. Since the use of video technology would not require any
modifications to an aircraft's communication or display systems, the
NTSB stated that this approach to recording DLCs might greatly reduce
the time and expense of retrofitting older aircraft.
    Our NPRM did not propose the installation of cockpit video cameras
and our regulatory evaluation did not include their use in cost
estimates or benefits analysis, nor has the use of cockpit video been
proposed for public or industry comment. The issue of cockpit video is
unsettled and would dramatically delay the implementation of DLC
recording standards that are already being developed internationally.
The FAA is not adverse to certification of an image recorder system
that meets the operational requirements of this rule, but no image
recording system will be mandated to comply with DLC recording
requirements.
7. TSO for DLC
    Bombardier recommended that a TSO for CVRs with datalink recording
capability be prepared and released for comment with any proposed
operating rule mandating the use of TSO approved equipment where DLC
recording is required.
    The FAA has issued TSO-C176 which identifies the minimum
performance standards for a Crash Protected Datalink Recorder. The TSO
is based on EUROCAE minimum performance standards document ED-112. Our
TSO allows the certification of a stand-alone recorder or a recorder
that combines this function with other recorder functions (DFDR, CVR).
    The ALPA disagreed with the proposal to record two hours of DLCs
and recommends they be recorded for the entire duration of flight. The
ALPA stated that the importance of DLCs to an investigation makes it
imperative that these communications be captured for the entire
duration of flight. The commenter believed this would most easily be
accomplished by recording these communications on the FDR.
    Since the duration of any particular flight is variable, the FAA
has established a minimum DLC recording duration of at least two hours
to match the requirement for the CVR. Ground stations also record CPDLC
messages, so any messages that occur outside of the 2-hour minimum
could be retrieved from a ground source.

N. Recordation of Cockpit Communication or Audio Signals

    The NPRM proposed that the expansion of the recordation of cockpit
audio signals be the same for all part 23 and part 25 aircraft
regardless of operating part. No comments were received on this portion
of the NPRM, and the proposal is adopted without change.

O. Checklist-to-Checklist Requirement

    The FAA proposed language to standardize across all operating parts
when CVRs must be in operation. This is known as the ``checklist to
checklist'' requirement.
    Five commenters, ATA, Boeing, Dassault, Northwest, and one
individual, said the proposed language was confusing. The ATA and one
individual commenter noted the proposed wording could require changes
to existing CVRs from ones that operate once electrical power is
applied to the respective power supply bus, to ones that can be
switched ``on'' or ``off'' by the flight crew when the checklist is
used.
    Northwest stated that while most of its aircraft appear to meet the
intent of this language, the proposed language could require an
automatic shutoff of the CVR on completion of the final checklist.
Since some CVR systems stop the CVR five minutes after final engine
shutdown, this situation would require a costly retrofit. Northwest
added that any such requirement should not be effective at the adoption
of the final rule, since changes may take longer to implement.
    Boeing proposed changing the language to clarify that the goal is a
minimum recording time as described. Boeing also suggests a longer
compliance time. It inferred the intent of the proposal is to record
cockpit voice communications as soon as possible before the flight and
as long as possible after the flight.
    The FAA reviewed the proposed language and agrees with the
commenters that a change in the current language could cause undue
confusion. It was never our intent to change the current operation of
CVRs. In preparing the NPRM, we found the existing regulations on CVR
start/stop criteria lacked consistency between operating parts. We were
trying to address this issue by proposing a single standard that
specified the minimum time period for CVR operation (checklist-to-
checklist). CVR operation was not intended to be limited to this
minimum time period, and existing CVR systems would not need to be
modified to run only during this minimum time period if their current
operation had them starting sooner or ending later than the proposed
criteria.
    We also discovered that providing consistent language throughout
the operating parts could be more complicated and confusing than
warranted by the minor inconsistencies that now exist. Questions of
compliance time, applicability to aircraft of certain age, and the
differences in the construction of the operating parts have caused us
to decide not to adopt the proposed language. Since we never intended
to change how CVRs operate, the decision to leave the current language
in the rules is not expected to have any negative effects. Where new
applicability paragraphs are being adopted, they will use the same
checklist language as had been used previously in that part.
    We received a considerable number of comments regarding specific
operation of CVRs under the proposed checklist to checklist
requirement. Since we have decided not to include the proposed change
in the final rule, we are not including any discussion of those
comments.

P. Deployable Recorders--Request for Comments

    In the NPRM, the FAA sought comments and information about the
feasibility of and specifications for a deployable flight recorder
system. We received 12 comments in response to this request. Eight
commenters (ALPA, DRS Technologies (DRS), Hall and Associates, LLC
(Hall), National Air Disaster Alliance/Foundation (NADA/F),
Representatives John J. Duncan, Jr. and William J. Pascrell, Jr. in a
joint submission, and Representatives Harold Rogers and David Price in
a joint submission) supported the use of deployable recorder systems.
These commenters cited a number of reasons for supporting deployable
flight recorders, including:
     Since fixed and deployable recorders have different
survivability characteristics, the use of both types would provide
maximum redundancy and improve the odds of recovering complete,
undamaged recorders for data analysis.
     Deployable system technology could dramatically reduce the
time and cost to locate and recover recorders.
     The expansion of aviation practices such as the production
of larger aircraft, increasing numbers of flights, increased polar and
over water flights, and the onset of free flight, present new demands
on investigators and compound the need for immediate access to better
information.
     The time savings associated with recovery would have a
dramatic affect on the U.S. economy. Since September

11, 2001, an airline crash without a known cause is more likely to
cause the traveling public to lose faith in the air transportation
system, costing the U.S. economy billions of dollars.
     Current recorder standards no longer meet safety and
security needs, where heightened security threats demand that officials
have complete information as quickly as possible to determine the cause
of a crash.
    Five commenters (Boeing, IATA, Northwest and two individuals) did
not support the use of deployable recorder systems for several reasons,
including:
     Since existing recording systems provide enough data and
are protected from all but the most extreme crash conditions, it is
doubtful that a deployable flight recorder would significantly increase
data survivability.
     The survivability and recoverability of the current fixed
recorders is acceptable and the costs of implementing deployable
recorder systems are not balanced by sufficient benefits.
     Deployable recorder systems may present a safety hazard if
the event of an inadvertent deployment over populated areas or active
runways, or if manual deployment distracts a flightcrew from its
primary tasks during an emergency.
     The safety hazards to maintenance personnel or the public
from a misfire are considerable.
    Smiths expressed neither objection to nor support for deployable
recorder systems, but said that, because of uncertain dynamics,
deployable systems should be qualified to the identical survivability
requirements as fixed recorders.
    The FAA appreciates all the information provided in response to our
request for comments. This information is helpful and will aid us in
understanding the technology involved, possible future applications for
deployable recorder systems, and the consequences of their design and
installation.
    Despite several requests, this final rule does not include a
requirement for deployable recorder systems. The request for comments
in the NPRM was made to bring the issue to the public's attention. We
would need significant amounts of information concerning design and
cost before we could begin to properly assess such an addition. We will
not delay the CVR and DFDR improvements promulgated in this final rule
while we continue our analysis of new technology. Deployable recorder
systems may be addressed in a future rulemaking action.

Q. Miscellaneous Comments

1. Applicability
    Four commenters (Boeing, Radiant and two individuals) suggested
changes to the general applicability of the proposed rule. Boeing
stated that all aircraft operating in the U.S. should be subject to the
proposed requirements. Boeing noted that accidents and incidents
involving non-U.S.-registered aircraft (such as EgyptAir 990) have been
the subject of FAA and NTSB investigations, and stated that the
additional data gained from investigations involving these aircraft
would be just as useful as in data gained during investigations of
U.S.-registered aircraft.
    Two individual commenters suggested that we expand the
applicability of the proposed rules. One recommended the rule apply to
all carriers, while another suggested the rule should apply to all
operators and manufacturers.
    In contrast, Radiant asked us to restrict the final rule to
aircraft with a ``reasonable service life remaining'' or a
``foreseeable future in commercial aviation.'' Radiant proposed
limiting the final rule to those aircraft models being manufactured as
of December 31, 2005. Radiant stated this change would result in a
modern CVR and independent power supply being installed in most of the
world fleet of active commercial aircraft.
    Like all countries, the FAA has limited authority to require the
installation of particular equipment on aircraft not on our registry
but merely flying in our airspace.
    Similarly, while the NTSB plays a primary role in investigating
accidents involving U.S.-registered aircraft, its role in
investigations involving other countries' aircraft is usually by
invitation. The accident investigation authority from the country in
which the aircraft is registered usually leads these investigations and
may ask the NTSB to participate. Other regulatory authorities are free
to increase the CVR/DFDR regulations for aircraft of their registry if
they desire.
    Further, this final rule changes the regulations in both
certification parts (23, 25, 27, and 29) and operating parts (91, 121,
125, 129, and 135), affecting anyone who is regulated by those parts.
While some operators were excluded from certain retrofit requirements
adopted here, that was done following considerable analysis that showed
a significant economic burden would be imposed. Our analysis
demonstrates that the scope of the final rule is sufficient to meet the
safety goal of more reliable flight information at an acceptable cost.
    Finally, Radiant did not provide any criteria for determining what
a ``reasonable service life remaining'' would be, nor its proposed
``foreseeable future in commercial aviation.'' As such, we have no
response. Radiant's proposed cutoff date (``airplanes that are still
being produced as of December 31, 2005'') would exclude several popular
aircraft models from the final rule, including the Boeing 757 and 737
``Classic,'' and all McDonnell Douglas airplanes. These airplanes are
expected to remain in the U.S. fleet in large numbers for many years.
Radiant's proposed date would also exclude seven of the eight aircraft
models involved in the incidents/accidents cited in the NTSB
recommendations that are the basis for this rulemaking. No changes to
the final rule were made based on these comments.
2. Harmonization
    Five commenters (AIA, Airbus, Boeing, Bombardier and one
individual) expressed concern that the proposal in the NPRM is not
harmonized with parallel activities currently being considered by the
JAA. These commenters consider it vital that these regulations are
harmonized or the affected industry could face conflicting
requirements, significant compliance costs and potentially complex
system designs in an attempt to satisfy two different sets of
regulations. The commenters suggest that a common set of technical
requirements be implemented within a similar time frame. Since both the
FAA and the JAA are proposing flight recorder changes, the commenters
urged the FAA to use this opportunity to harmonize the requirements
before promulgating a final rule.
    The FAA continues to work with JAA (and we will work with the
European Aviation Safety Agency (EASA) when it takes over
responsibility for this issue from the JAA), ICAO and other non-U.S.
regulatory bodies to harmonize our regulations whenever possible, but
we do not change our position or our regulations solely for the sake of
harmonization. When we determine that the need exists for a certain
regulation, and the other regulatory agencies find that a more
stringent or lenient requirement is appropriate, we review their
findings and will revise our regulation if our regulatory goals are
met, an equivalent level of safety is achieved, and there is no burden
imposed on the industry if a change is made. This is the approach we
have taken when drafting the NPRM and this

final rule, but we will not delay the timing of our rulemaking simply
to accommodate the continuing consideration of issues by numerous other
regulatory bodies.
3. Definition of ``Date of Manufacture''
    Dassault noted the ``date of manufacture'' determines the
applicability of certain requirements and the NPRM does not define this
term. This omission could lead to different interpretations and
disagreements between operators, manufacturers and the FAA. Therefore,
Dassault recommended the FAA define this term in the final rule.
    While we use the term `date of manufacture' in several regulations,
we do not routinely define it each time. In general, the date of
manufacture is usually considered the date an aircraft receives its
airworthiness certificate. There may be other circumstances that modify
this date, however, and we will not attempt to set a strict definition
for purposes of this rule.
4. CVRs--Automatic Stop Requirement
    The NTSB and Airbus recommended removal of the existing requirement
that CVRs have an automatic means of stopping 10 minutes after crash
impact. They both noted the proposal to replace the 30-minute CVR with
a 2-hour CVR makes this requirement less important.
    While it may seem appropriate to remove a rule that was originally
written for short-duration recorders, removal of a certification rule
has a broader impact than suggested by the commenters. Because the 2-
hour recorder requirement is an operating rule, the effect of removing
a certification requirement is not parallel. And although the 10-minute
rule may be considered less important, it is not without merit and
cannot be considered unnecessary.
    The commenters did not make a case that the current certification
requirement is burdensome, or that it is a hindrance or inconsistent
with the proposed new operating requirements, only that it is less
important than it once was. The NTSB comment indicates that its real
concern is the use of switches that can be activated prematurely as a
means of implementing the stop criteria. While the NTSB suggested that
gravitation accelerator switches (g-switches) can be removed at the
time of replacement with a 2-hour solid state recorder, their
suggestion does not include the actual g-switch ban they desire, the
regulation in which that change might be implemented, or the costs to
implement it. The two largest aircraft manufacturers are already
producing airplanes with 2-hour solid state recorders, which means the
aircraft already comply with the rule. Removing the g-switches would be
a new retrofit on which we have not solicited comment, including
alternative technologies for complying with the certification rule, and
for which we have no cost estimates. The comments are insufficient to
support the need for, and do not properly estimate the scope of, the
recommended change. No change has been made to the regulations based on
this comment.
5. FDRs--Start/Stop Criteria
    The ALPA recommended changing the DFDR start/stop criteria to
mirror the proposed CVR criteria for newly manufactured and new
certificated designs. It noted that at least one manufacturer has DFDR
start/stop criteria based on the status of the parking brake, which can
adversely affect the ability to obtain complete, accurate or relevant
DFDR data.
    The NTSB proposed different DFDR start/stop criteria. The NTSB
stated that the FDR should start operating either before engine start
for the purpose of flight or by an automatic means when engine oil
pressure is sensed on any engine. The DFDR should then operate
continuously until termination of the flight when all engines are shut
down.
    The NTSB also requested a change to the airworthiness requirements
in the regulations. This change would provide for the automatic
application of electrical power to the DFDR at liftoff to safeguard
against the failure of any automatic or manual means of powering the
DFDR.
    The FAA is not including the changes to DFDR start/stop criteria.
There is no historical evidence that the start/stop functions on
aircraft have interfered with accident investigations. The only
aircraft cited by ALPA are no longer in production, so requirements for
newly manufactured airplanes would have no effect. We believe the
existing regulations on DFDR start/stop criteria are satisfactory.
These regulations require the DFDR to operate from the instant the
airplane begins its takeoff roll until it has completed its landing
roll. We believe this standard allows the DFDR to capture all the
critical data from the recorded parameters during all phases of flight.
    In addition, neither ALPA nor the NTSB indicated how their proposed
changes would significantly improve the quality or quantity of
information recorded, or increase the potential for retaining important
information needed during accident and incident investigations. As the
NTSB pointed out, most airframe manufacturers and operators already
begin DFDR operation at engine start. Therefore, the proposed changes
would have no effect on these aircraft. As for the Canada Air
Challenger CL-600 accident cited by the NTSB, this is not an example of
a drawback of the existing DFDR start/stop criteria. The manufacturer's
design to start DFDR operation once the anti-collision (strobe) light
switch is placed in the ``on'' position allows operators to meet the
existing DFDR start/stop criteria (as long as the switch is ``on''
before takeoff roll begins). The fact that the pilots of the CL-600
involved in the accident failed to take this step implies an
operational error and not a design problem with the airplane.
    Finally, changing the FDR start/stop criteria was not proposed in
the NPRM. We did not perform a regulatory evaluation of the impact of
this change, and no costs for implementation were provided by either
commenter suggesting it. Since we are unable to support the change as
necessary, we are not incorporating it in this final rule.
6. DFDR Activation Switch--Request for Comments
    In the NPRM, the FAA requested comments on the cost to retrofit a
switch for the flight crew to activate the DFDR to record at the start
of the checklist. We received only one comment in response to this
request. Boeing asked if there was a typo in the request (CVR rather
than DFDR), as this subject matter is not discussed elsewhere in the
NPRM.
    The request for comments on this subject was an error in the NPRM.
We believe the existing regulations on DFDR start/stop criteria are
satisfactory.

R. Errors and Inconsistencies in NPRM

    Dassault noted the sampling interval of parameter 23 in Appendix F
to part 135 would change from 0.5 (= 2 Hz) to 0.25 (= 4 Hz). However,
the sampling interval for the same parameter in Appendix M to part 121
and Appendix E to part 125 remains unchanged (0.5 (= 2 Hz)). Dassault
recommended no change to parameter 23 in Appendix F to part 135 so it
is consistent with Appendix M to part 121 and Appendix E to part 125.
    The proposed changes to parameter 23 in Appendix F were in error.
No change is being made to that parameter.
    Airbus and Boeing noted that proposed Sec.  129.1(b) removes the
requirement that Sec. Sec.  129.16, 129.32, and 129.33 apply to
operations of U.S.-registered aircraft solely outside the U.S. Those
sections refer to damage-tolerance inspections, repair assessments and

aging airplane requirements. Airbus and Boeing assumed this omission
was inadvertent and recommended the FAA change Sec.  129.1(b) to
reinsert these requirements.
    The FAA thanks the commenters for bringing this to our attention.
The proposed rule intended only to add new Sec.  129.22 (now Sec.
129.24) to the applicability of Sec.  129.1(b), not to eliminate any
existing requirements. This has been corrected in the final rule.
    Airbus and Boeing noted errors in part 121 Appendix M, part 125
Appendix E and part 135 Appendix F for the resolution of parameters
12a, 14a, 15 and 88. They stated that they believe the existing
resolutions for these parameters are correct and were not meant to be
changed.
    The FAA agrees. The final rule reflects the resolutions for those
four parameters without change.
    Boeing stated the new wording in the ``Remarks'' column for
parameter 1 in part 121 Appendix M is unclear. Boeing noted its
preference for the existing language and proposed the FAA keep it.
    The published version of the NPRM introduced an error; the
``Remarks'' column was not intended to be changed except to correct the
word ``second'' to ``seconds.''
    Boeing recommended the FAA make several editorial changes to part
121, Appendix M as clarifications:
    (i) In the ``Parameters'' column for Parameter 23, insert the word
``speed'' before ``brake.''
    (ii) In the ``Parameters'' column for Parameter 19, change the word
``trime'' to ``trim.''
    (iii) In the ``Resolution'' column for Parameter 26, revise the
existing wording ``1 ft + 5% above 500 ft'' to read ``1 ft up to and
including 500 ft, 1 ft + 5% of full range above 500 ft.''
    The Parameter 23 listing is corrected in the final rule. Since the
Parameter 19 listing is correct in the 2006 Code of Federal
Regulations, no further action is necessary. Regarding the Parameter 26
listing, Boeing presented nothing to indicate that the current text is
a problem or has led to misunderstanding, and has given no reason other
than its preference why this should be revised. No change has been made
in the final rule.
    Boeing also stated that the ``Remarks'' column for Parameter 85
should be corrected, from ``0.5 second'' to ``2 seconds'' because, when
sampled alternately at 4-second intervals as indicated in the table,
the result will provide a sample each two seconds.
    The commenter is misreading the rule; the specification is correct
as published. The suggested rewording would double the sample time. Two
seconds refers to four interleaved samples of 0.5 seconds each.
    Honeywell had two comments about the language in Sec.  91.609.
First, Honeywell noted the proposed addition of paragraphs (i), (j) and
(k) and asked why there is no paragraph (h). Second, Honeywell asked
why the phrase ``* * * using a recorder that meets the standards of
TSO-C124a, or later revision'' is missing in Sec.  91.609(c)(2) when it
is in Sec.  91.609(c)(3) and other proposed similar revisions.
    In 1999, the FAA issued Notice No. 99-19 (64 FR 63140, November 18,
1999), which proposed to increase the number of DFDR parameters
required for all Boeing 737 series airplanes. A new paragraph (h) for
Sec.  91.609 was part of that proposal. When this rule was proposed,
the next available paragraph was (i). Since this final rule will
publish before the 1999 proposal, the paragraphs added to Sec.  91.609
in this rule will be (h), (i) and (j).
    Honeywell is incorrect about including TSO-C124a in Sec.
91.609(c)(2). Inclusion of the standard would be a retrofit we did not
intend nor estimate the costs for. The TSO-C124a standard is for newly
manufactured aircraft only.

S. Items Not Proposed

    Four commenters (ALPA, the NTSB and two individuals) recommended
the FAA add new CVR and DFDR requirements as part of this final rule.
    The ALPA requested that we require all newly manufactured CVRs and
DFDRs to meet the underwater locator beacon (ULB) security-of-
attachment standard specified in the EUROCAE ED-112 document. The ALPA
noted that in some recent accidents there have been cases where the ULB
has become nearly or fully separated from the CVR or FDR memory module.
    The ULB standard of ED-112 standard is included in all of the new
FAA TSOs on recorders (numbers 123b, 124b, 166 and 167).
    Three commenters (NTSB, ALPA and L3) recommended that the FAA
require the replacement of magnetic tape flight recorders in the final
rule. The commenters noted that magnetic tape FDRs are more problematic
than magnetic tape CVRs and far less reliable than solid-state DFDRs.
    The replacement of magnetic tape flight recorders was not proposed
in the NPRM and represents a significant change that is beyond the
scope of the rulemaking. The commenters did not provide any data on the
extent of usage or the cost of replacement, nor has the public
(including affected operators) been allowed to comment. The final rule
does not contain a provision requiring the replacement of magnetic tape
FDRs.
    The ALPA expressed concern the FAA did not propose any new
requirements in response to NTSB Safety Recommendation A-03-050 that
was issued following the Board's investigation of the American Airlines
flight 587 accident that occurred at Jamaica Bay, New York on November
12, 2001. During the investigation, the NTSB determined that the rudder
(and other) control surface position information recorded on the DFDR
was filtered before it was recorded. This filtering made it difficult
for the NTSB to approximate the actual rudder surface movement during
the accident. The NTSB recommended that the FAA act to remove known
flight control parameter filtering on three models of aircraft. In its
comment, ALPA urged the FAA, as part of this rulemaking, to consider
additional DFDR modifications in response to the NTSB recommendation.
    On July 7, 2004, the FAA hosted a public meeting to discuss the
NTSB recommendation and the issue of filtered flight data in general.
The purpose of this meeting was to gather information from industry and
other interested parties about current practices on processing of data
as it is recorded on all transport airplanes. Representatives from
Airbus, ALPA, the Allied Pilots Association (APA), Boeing and the NTSB
each made presentations at the meeting.
    We completed our analysis of issues surrounding filtered flight
data and the options available to us to address the NTSB's
recommendation. On November 15, 2006, we published a proposed rule that
addresses filtered flight data (71 FR 66634) and this subject is being
addressed as a separate regulatory issue.
    Six commenters supported the use of a ground recording system. Five
of these commenters (APA, AirTran, RAA and two individuals) raised this
issue as part of their objection to the datalink communication (DLC)
proposal. These commenters noted that ground recording is a more cost
efficient means of capturing DLCs since the same data that will be
recorded on the aircraft is available for accident investigation at the
receiving ground based stations. These commenters see no merit in
requiring DLC recording on aircraft.
    The remaining individual commenter suggested a ground recording
system as an alternative to recording any data on an aircraft as this
would eliminate the loss of data during a crash.
    The FAA agrees that ground recording systems are a useful tool to
assist in accident investigations. However, these systems cannot be
adopted as the

primary source of data recording. In the past, the NTSB and other
accident investigators have encountered significant problems in
acquiring ground recorded data. Liability and other legal concerns have
caused some private entities that perform ground recording and some
foreign governments to delay the release of recorded data for long
periods. The NTSB and other accident investigators have repeatedly
expressed their desire that recorded data remain on the aircraft
because of the immediate availability of the data once the recorders
are located.
    Further, for ground recording systems to function as intended, all
countries or private entities recording data would need compatible
systems, the specifications for which have not been proposed. There are
no international standards in place for such recording, and we have no
way of ensuring that it would happen.
    The ALPA suggested we require a system that provides an electronic
common time reference information to the CVR, the DFDR, and any other
onboard recorders. They noted that, as part of every accident
investigation, the relative timing of the CVR and DFDR events must be
determined, and that it is a manual, labor-intensive effort by accident
investigators that could introduce uncertainty into the results. A
system to provide electronic common time reference information to the
CVR and DFDR would eliminate these problems.
    The NTSB viewed installing the new 2-hour CVR as an ideal
opportunity to require all aircraft equipped with a CVR to also have
pilot boom microphones.
    An individual asked us to consider accelerometer outputs and wheel
rotation as required parameters. The commenter noted that current
accelerometer outputs are extremely noisy, making it difficult to
extract usable data. The commenter suggested that recording wheel
rotation is an excellent way of determining initial touchdown.
    For the balance of the issues, none of these were included in the
NPRM and are beyond the scope of the proposed rule changes. The
commenters did not submit any data on the cost of the suggested
changes, nor have they been estimated as part of this rulemaking. While
they may be worthy considerations for future rulemaking, none of the
suggested changes are necessary as part of the changes being adopted in
this rulemaking. No changes have been made to the final rule based on
these suggestions.

T. Comments on Cost/Benefit Analysis

    Empire Airlines said that the FAA's cost-benefit analysis did not
consider the cumulative economic impact of the several operational and
equipment rules the agency has issued during the last two years.
    Our regulatory evaluations estimate the cost of each rule
individually. Different rules affect different parties and the
cumulative impact on any one operator would be impossible to estimate
and would not be relevant for any other operator.
    An individual commented that the FAA's economic analysis did not
include the cost to re-engineer equipment and to install the equipment
for recording datalink communications if DLC equipment is installed
after the compliance date.
    In the Initial Regulatory Evaluation, we estimated a cost of
$762,500 the first time a manufacturer engineers a DLC recording
system. We estimated a cost of $262,500 for engineering the second
airplane model, presuming much of the work from the first can carry
over. Similarly, we estimated an engineering cost of $75,000 for each
remaining model in a series. Retrofitting an aircraft to be DLC capable
would require significant engineering, while the cost of engineering to
record datalink communications would be a minimal extension of the
overall effort with a resultant minimal cost.
    Bell Helicopter stated that compliance with the ``no single
electrical failure could disable both the CVR and DFDR'' requirement is
open to two interpretations--each of which would have different cost
implications. If the correct interpretation were that ``No failure of a
single electrical bus shall disable both the CVR and DFDR'', it
estimates that it would cost $100,000 per ``application'' to comply
with the rule, plus a recurring cost of approximately $5,000 to the
operator. If the correct interpretation is that ``No single electrical
failure external to the recorder, or the failure of any single
electrical component within a combined CVR/DFDR, shall disable both the
CVR and DFDR'', Bell states that all or most of the current recorders
will be obsolete. If this occurs, ``a major industry wide design will
be required.'' Bell estimates that costs for development of a new
recorder and TSO would be in the millions of dollars, recertification
costs will be approximately $250,000 per model, and the recurrent costs
to operators will approach $50,000 per rotorcraft to replace existing
recorders.''
    As discussed previously, we have added the phrase ``external to the
recorder'' to clarify our intent. We accept Bell's estimated cost of
$100,000 per model with a recurring cost of $5,000 to the operator. The
IATA commented that the airlines must carry the costs of all the new
requirements, and that the FAA did not substantiate the benefits of the
proposed changes in the accidents cited in the NPRM. The IATA also
noted that the proposed benefits are speculative, in that they ``may
result in safety benefits,'' and thus do not justify the costs in
equipment and impact on operations.
    As described in the Initial Regulatory Evaluation, any benefits
from this final rule are dependent upon investigating authorities
gaining additional, better quality information that they are able to
use to determine the causes of future accidents with greater certainty,
which could result in safety improvements being adopted sooner. We are
unable to predict with certainty whether this additional information
will or will not provide incremental benefits in the investigation of
any future accident or incident. This has always been true for flight
recorder requirements, which by nature do not fit the traditional cost/
benefit analysis. As always, we rely on the expertise of the NTSB that
the additional information is important to its ability to fully
investigate accidents and incidents as aircraft technology evolves.
    Regarding the proposal to require 2-hour solid state CVRs,
Northwest commented that it would have to modify 105 of its 30-minute
solid state CVRs at a cost of $767,000 (a per airplane cost of about
$7,300) and replace 15 CVRs at a cost of $180,000 (a per airplane cost
of $12,000).
    In the Initial Regulatory Evaluation, we estimated retrofitting a
30-minute solid state CVR would cost about $8,140 ($7,500 for the
equipment and $640 for the labor). Since our estimates were based on
older information, we accept Northwest's estimate of $7,300 per
airplane and have used it in the Final Regulatory Evaluation. We also
estimated that it would cost $17,500 to replace a unit, and are
adopting Northwest's estimate for use in the Final Regulatory
Evaluation. No other comments on these costs were received.
    Northwest also described three costs it believes should be added to
the regulatory evaluation: (1) The cost to modify a solid-state CVR
from TSO-C123 to TSO-C123a; (2) The cost for new test equipment to
download and decode additional datalink information from the CVR; and
(3) The additional routine maintenance cost, such as battery
reconditioning, for the CVR-RIPS installed on new aircraft.

    Regarding the cost of conversion to TSO-C123a, we contacted four of
the major equipment vendors, who stated that their CVRs manufactured
under TSO-C123 already meet the requirements of TSO-C123a, and that if
necessary, a service bulletin could be issued to re-identify the
recorder.
    Regarding the cost of DLC test equipment, as we stated in the
Initial Regulatory Evaluation, we believe this cost would be minimal.
Northwest did not provide any estimated costs for this item, no other
commenter raised it as a cost issue, and DLC remains an optional
installation. Accordingly, we have no basis to change our estimates on
the cost of this item.
    Regarding additional maintenance costs, in the Initial Regulatory
Evaluation we estimated that the average RIPS battery would be replaced
every two years; we will continue to use that estimate in our cost
calculations. We also estimated that one additional hour would be
required for the CVR-RIPS system maintenance; we have used that
estimate in our cost calculations in the Final Regulatory Evaluation.
    Boeing stated that the total cost of all the proposed requirements
were undervalued by 20 to 35 percent. In making this statement, Boeing
cites costs associated with equipment, testing, and certification and
``uncertainties in the statement of work'' such as the DLC requirements
``are driving a level of assumptions that affect potential cost
outcomes.''
    We accept that Boeing's information is based on more recent
information than we used for the Initial Regulatory Evaluation, and
have revised our Final Regulatory Evaluation to include this estimate.
No other commenters presented specific information addressing this
issue.

Section-By-Section Analysis

    The following is a summary of the changes to the current text of
the regulations. This summary does not include the reasons for these
changes because we have already discussed them as part of the above
disposition of comments.

A. Part 23--Airworthiness Standards: Normal, Utility, Acrobatic, and
Commuter Category Airplanes

    Section 23.1457, Cockpit voice recorders, is being amended to:
    (1) Add a new paragraph (a)(6) requiring the recordation of
datalink communications. No change was made from the language proposed
in the NPRM.
    (2) Amend paragraph (d)(1) to add the duration of CVR power as a
sentence at the end of the paragraph. No change was made from the
language proposed in the NPRM.
    (3) Add a new paragraph (d)(4) regarding a single electrical
failure not disabling the CVR and DFDR. The final rule adds the phrase
``external to the recorder'' as requested by commenters to clarify
where the failure may not occur.
    (4) Add a new paragraph (d)(5) that requires an independent power
source for the CVR and the cockpit-mounted area microphone, the
capacity for automatic switching to the independent source, and the
allowable location of the power source. At the request of the
commenters, the final rule specifies the duration of power as 10 +/-1
minutes, adds the area microphone, and specifies the location of the
power source.
    (5) Add a new paragraph (d)(6) requiring that the CVR be in a
separate container from the flight data recorder. No change was made
from the language proposed in the NPRM.
    (6) Revise paragraph (e) by expanding the CVR location requirements
to include the use of a combination recorder that acts as the CVR and
its location near the cockpit. This was not included in the language
proposed in the NPRM. Comments concerning the use of combination
recorders with an independent power source led to the addition of these
provisions to clarify these possibilities and change the allowable
location of the CVR.
    Section 23.1459, Flight data recorders, is being amended to:
    (1) Revise paragraph (a)(3) to add the duration of DFDR power as a
sentence at the end of the paragraph. No change was made from the
language proposed in the NPRM.
    (2) Add a new paragraph (a)(6) regarding a single electrical
failure not disabling the CVR and DFDR. The final rule adds the phrase
``external to the recorder'' as requested by commenters to clarify
where the failure may not occur.
    (3) Add a new paragraph (a)(7) requiring that the DFDR be in a
separate container from the CVR, and that a combination recorder may be
used. If a combination recorder is used to comply with the CVR
requirement and located near the cockpit, the aft-mounted DFDR used to
comply with this paragraph must also be a combination unit. The
language proposed in the NPRM was changed to mirror the revised
requirement for CVRs in Sec.  23.1457(d)(6) and (e)(2).

B. Part 25--Airworthiness Standards: Transport Category Airplanes

    Section 25.1457, Cockpit voice recorders, is being amended to:
    (1) Add a new paragraph (a)(6) requiring the recordation of
datalink communications. No change was made from the language proposed
in the NPRM.
    (2) Amend paragraph (d)(1) to add the duration of CVR power as a
sentence at the end of the paragraph. No change was made from the
language proposed in the NPRM.
    (3) Add a new paragraph (d)(4) regarding a single electrical
failure not disabling the CVR and DFDR. The final rule adds the phrase
``external to the recorder'' as requested by commenters to clarify
where the failure may not occur.
    (4) Add a new paragraph (d)(5) that requires an independent power
source for the CVR and the cockpit-mounted area microphone, the
capacity for automatic switching to the independent source, and the
allowable location of the power source. At the request of the
commenters, the final rule specifies the duration of power as 10  1 minutes, adds the area microphone, and specifies the location
of the power source.
    (5) Add a new paragraph (d)(6) requiring that the CVR be in a
separate container from the flight data recorder. No change was made
from the language proposed in the NPRM.
    (6) Revise paragraph (e) by expanding the CVR location requirements
to include the use of a combination recorder that acts as the CVR and
its location near the cockpit. This was not included in the language
proposed in the NPRM. Comments concerning the use of combination
recorders with an independent power source led to the addition of these
provisions to clarify these possibilities and change the allowable
location of the CVR.
    Section 25.1459, Flight data recorders, is being amended to:
    (1) Revise paragraph (a)(3) to add the duration of DFDR power as a
sentence at the end of the paragraph. No change was made from the
language proposed in the NPRM.
    (2) Add a new paragraph (a)(7) regarding a single electrical
failure not disabling the CVR and DFDR. The final rule adds the phrase
``external to the recorder'' as requested by commenters to clarify
where the failure may not occur.
    (3) Add a new paragraph (a)(8) requiring that the DFDR be in a
separate container from the CVR, and that a combination recorder may be
used. If a combination recorder is used to comply

with the CVR requirement and located near the cockpit, the aft-mounted
DFDR used to comply with this paragraph must also be a combination
unit. This language proposed in the NPRM was changed to mirror the
revised requirement for CVRs in Sec.  25.1457(d)(6) and (e)(2).

C. Part 27--Airworthiness Standards: Normal Category Rotorcraft

    Section 27.1457, Cockpit voice recorders, is being amended to:
    (1) Add a new paragraph (a)(6) requiring the recordation of
datalink communications. No change was made from the language proposed
in the NPRM.
    (2) Revise paragraph (d)(1) to add the duration of CVR power as a
sentence at the end of the paragraph. No change was made from the
language proposed in the NPRM.
    (3) Add a new paragraph (d)(4) regarding a single electrical
failure not disabling the CVR and DFDR whether installed as separate
units or as a single combined unit. The final rule adds the phrase
``external to the recorder'' as requested by commenters to clarify
where the failure may not occur.
    (4) Add a new paragraph (d)(5) that requires an independent power
source for the CVR and the cockpit-mounted area microphone, the
capacity for automatic switching to the independent source, and the
allowable location of the power source. At the request of the
commenters, the final rule specifies the duration of power as 10  1 minutes, adds the area microphone, and specifies the location
of the power source.
    (5) Add a new paragraph (h) to allow the installation of a single
combined unit when both a cockpit voice recorder and flight data
recorder are required. The language was changed to clarify that
combination recorders must meet all of the CVR and DFDR standards.
    Section 27.1459, Flight data recorders, is being amended to:
    (1) Revise paragraph (a)(3) to add the duration of DFDR power as a
sentence at the end of the paragraph. No change was made from the
language proposed in the NPRM.
    (2) Add a new paragraph (a)(6) regarding a single electrical
failure not disabling the CVR and DFDR whether installed as separate
units or as a single combined unit. The final rule adds the phrase
``external to the recorder'' as requested by commenters to clarify
where the failure may not occur.
    (3) Add a new paragraph (e) to allow the installation of a single
combined unit when both a cockpit voice recorder and flight data
recorder are required. The language was changed to clarify that
combination recorders must meet all of the CVR and DFDR standards.

D. Part 29--Airworthiness Standards: Transport Category Rotorcraft

    Section 29.1457, Cockpit voice recorders, is being amended to:
    (1) Add a new paragraph (a)(6) requiring the recordation of
datalink communications. No change was made from the language proposed
in the NPRM.
    (2) Revise paragraph (d)(1) to add the duration of CVR power as a
sentence at the end of the paragraph. No change was made from the
language proposed in the NPRM.
    (3) Add a new paragraph (d)(4) regarding a single electrical
failure not disabling the CVR and DFDR whether installed as separate
units or as a single combined unit. The final rule adds the phrase
``external to the recorder'' as requested by commenters to clarify
where the failure may not occur.
    (4) Add a new paragraph (d)(5) that requires an independent power
source for the CVR and the cockpit-mounted area microphone, the
capacity for automatic switching to the independent source, and the
allowable location of the power source. At the request of the
commenters, the final rule specifies the duration of power as 10  1 minutes, adds the area microphone, and specifies the location
of the power source.
    (5) Add a new paragraph (h) to allow the installation of a single
combined unit when both a cockpit voice recorder and flight data
recorder are required. The language was changed to clarify that
combination recorders must meet all of the CVR and DFDR standards.
    Section 29.1459, Flight data recorders, is being amended to:
    (1) Revise paragraph (a)(3) to add the duration of DFDR power as a
sentence at the end of the paragraph. No change was made from the
language proposed in the NPRM.
    (2) Add a new paragraph (a)(6) regarding a single electrical
failure not disabling the CVR and DFDR whether installed as separate
units or as a single combined unit. The final rule adds the phrase
``external to the recorder'' as requested by commenters to clarify
where the failure may not occur.
    (3) Add a new paragraph (e) to allow the installation of a single
combined unit when both a cockpit voice recorder and flight data
recorder are required. The language was changed to clarify that
combination recorders must meet all of the CVR and DFDR standards.

E. Part 91--General Operating and Flight Rules

    Section 91.609, Flight data recorders and cockpit voice recorders,
is being amended to:
    (1) Add a new paragraph (c)(2) that includes the separate container
requirements for CVRs and DFDRs on part 23 or part 25 airplanes. The
requirement to retain the last 25 hours of recorded DFDR data, which
was proposed in the NPRM as a retrofit, is not included.
    (2) Add a new paragraph (c)(3), applicable to aircraft manufactured
two years after the effective date of this rule, that requires
compliance with all provisions of the flight data recorder
certification requirements in Sec. Sec.  23.1459, 25.1459, 27.1459, or
29.1459, as applicable. The additions to these sections include the
power duration requirement, the single electrical failure requirement,
and the separate container/combination unit requirements noted in the
amendments to the certification parts. New paragraph (c)(3) also
requires that these newly manufactured airplanes have DFDRs that retain
the last 25 hours of recorded information using a recorder that meets
the standard of TSO-C124a, or later revision. The language proposed in
the NPRM was changed slightly for clarification; no substantive changes
to the proposed requirements were made.
    (3) The proposed revision to paragraph (e)(2) to include new
``checklist-to-checklist'' language is not included in this final rule.
No retrofit of this new procedure is required; the previous version of
this language in paragraph (e)(2) remains in effect.
    (4) Add a new paragraph (h) that includes the separate container
requirements for CVRs and DFDRs on part 23 or part 25 airplanes. (Note
that this was proposed as paragraph (i) because the paragraph (h)
designation was proposed in a separate rulemaking that is not yet
final). This paragraph also requires transport category airplanes to
meet additional recording requirements in Sec. Sec.  23.1457 or
25.1457, as proposed in the NPRM. The requirement to retain two hours
of recorded information on a CVR that meets the requirements of TSO-
C123a, which was proposed in the NPRM as a retrofit, is not included.
    (5) Add a new paragraph (i), applicable to aircraft manufactured
two years after the effective date of this rule, that requires
compliance with all provisions of the cockpit voice recorder
certification requirements in Sec. Sec.  23.1457, 25.1457, 27.1457, or
29.1457, as applicable. The additions to these sections include the
power duration

requirement, the single electrical failure requirement, and the
separate container/combination unit requirements noted in the
amendments to the certification parts. This paragraph also requires
that newly manufactured airplanes retain the last two hours of recorded
information and that the CVR meets the requirements of TSO-C123a, or
later revision. These requirements are adopted as proposed, except for
a change in the paragraph designation.
    (6) Add a new paragraph (j) that requires all airplanes and
rotorcraft that are required to have a CVR to record datalink
communications if they install DLC equipment two years after the
effective date of this rule. This requirement is adopted as proposed
except for a change in the paragraph designation.
    (7) Appendix E to part 91, Airplane Flight Recorder Specifications,
is being amended to add footnote 5 to the parameter for Stabilizer Trim
Position or Pitch Control Position. No change was made from the
language proposed in the NPRM.
    (8) Appendix F to part 91, Helicopter Flight Recorder
Specifications, is being amended to add footnote 4 changing the
sampling interval for five parameters. No change was made from the
language proposed in the NPRM.

F. Part 121--Operating Requirements: Domestic Flag and Supplemental
Operations

    Section 121.343, Flight recorders, is being amended to:
    (1) Revise the title of the section to say ``Flight data
recorders.''
    (2) Revise paragraph (c) to change the date from 1994 to 1995.
    (3) Add a new paragraph (m) to specify that after August 20, 2001,
Sec.  121.343 applies only to the aircraft models listed in Sec.
121.344(l)(2). No change was made from the language proposed in the
NPRM.
    Section 121.344, Digital flight data recorders for transport
category airplanes, is being amended to add a new paragraph (m) that
requires all newly manufactured airplanes comply with additional
paragraphs of Sec.  25.1459, and have a DFDR that retains the last 25
hours of recorded information and meet the standards of TSO-C124a, or
later revision. No change was made from the language proposed in the
NPRM, except for the paragraph designation.
    Section 121.344a, Digital flight data recorders for 10-19 seat
airplanes, is being amended to add a new paragraph (g) that requires
all newly manufactured airplanes comply with additional paragraphs of
Sec. Sec.  23.1459 or 25.1459, and have DFDRs that retain the last 25
hours of recorded data and meet the standards of TSO-C124a, or later
revision. No change was made from the language proposed in the NPRM.
    Section 121.359, Cockpit voice recorders, is being amended to:
    (1) Add a new paragraph (i) that requires airplanes manufactured
before April 7, 2010 be retrofitted with CVRs that meet the separate
container requirement, retain the last two hours of recorded
information using a CVR that meets the standard of TSO-C123a, or later
revision, and meet additional recording requirements in Sec. Sec.
23.1457 or 25.1457. Four years is allowed for the retrofit of these
items. We are not adopting the checklist to checklist language proposed
in the NPRM. We are adopting the same checklist to checklist language
as exists in other applicability paragraphs of this section. Otherwise,
no change was made from the language proposed in the NPRM.
    (2) Add a new paragraph (j) that requires newly manufactured
airplanes have a CVR that meets all of Sec. Sec.  23.1457 or 25.1457,
and retains the last two hours of recorded information using a CVR that
meets the standard of TSO-C123a, or later revision. We are not adopting
the checklist to checklist language proposed in the NPRM. We are
adopting the same checklist to checklist language as exists in other
applicability paragraphs of this section. Otherwise, no change was made
from the language proposed in the NPRM.
    (3) Add a new paragraph (k) that requires the recordation of
datalink communications if DLC equipment is installed two years after
the effective date of this rule. No change was made from the language
proposed in the NPRM.
    Appendix M to part 121, Airplane Flight Recorder Specifications, is
amended to:
    (1) Revise parameter 1 to correct a typographical error.
    (2) Revise parameters 12a, 12b, 13a, 13b, 14a, 14b, 15, 16, 17, and
88 to add footnote 18 (proposed as footnote 20) for newly manufactured
airplanes. Footnote 18 changes the seconds per sampling interval to
0.125 for these parameters and prohibits alternate sampling
(interleaving). The NPRM proposed 16 Hz for these parameters; the final
rule requires they be sampled and recorded at 8 Hz, and adds the
prohibition on interleaving samples.
    (3) The NPRM publication of the appendix included several errors in
the resolution column; none of the current resolution percentages are
being changed.

G. Part 125--Certification and Operations: Airplanes Having a Seating
Capacity of 20 or More Passengers or a Maximum Payload Capacity of
6,000 Pounds or More; and Rules Governing Persons On Board Such
Aircraft

    Section 125.225, Flight recorders, is being amended to:
    (1) Revise the title of the section to say ``Flight data
recorders.''
    (2) Add a new paragraph (j) to specify that after August 20, 2001,
Sec.  125.225 applies only to the aircraft models listed in Sec.
125.226(l)(2). No change was made from the language proposed in the
NPRM.
    Section 125.226, Digital flight data recorders, is being amended to
add a new paragraph (m) that requires all newly manufactured airplanes
comply with additional paragraphs of Sec.  25.1459, and have a DFDR
that retains the last 25 hours of recorded data and meet the standards
of TSO-C124a, or later revision. No change was made from the language
proposed in the NPRM, except for the paragraph designation.
    Section 125.227, Cockpit voice recorders, is being amended to:
    (1) Add a new paragraph (g) that requires airplanes manufactured
before April 7, 2010 to retrofit their CVRs to meet the separate
container requirement, retain the last 2 hours of recorded information
using a CVR that meets the standard of TSO-C123a, or later revision,
and meet additional paragraphs of Sec.  25.1457. Four years is allowed
for the retrofit of these items. We are not adopting the checklist to
checklist language proposed in the NPRM. We are adopting the same
checklist to checklist language as exists in paragraph (a) of this
section. Otherwise, no change was made from the language proposed in
the NPRM.
    (2) Add a new paragraph (h) that requires newly manufactured
airplanes have a CVR that meets all of Sec.  25.1457, retains the last
2 hours of recorded information using a CVR that meets the standard of
TSO-C123a, or later revision. We are not adopting the checklist to
checklist language proposed in the NPRM. We are adopting the same
checklist to checklist language as exists in paragraph (a) of this
section. Otherwise, no change was made from the language proposed in
the NPRM.
    (3) Add a new paragraph (i) that requires the recordation of
datalink communications if DLC equipment is installed two years after
the effective date of this rule. No change was made from the language
proposed in the NPRM.
    Appendix E to part 125, Airplane Flight Recorder Specifications, is
being amended to:

    (1) Revise parameters 12a, 12b, 13a, 13b, 14a, 14b, 15, 16, 17, and
88 to add footnote 18 (proposed as footnote 20) for newly manufactured
airplanes. Footnote 18 changes the seconds per sampling interval to
0.125 for these parameters and prohibits alternate sampling
(interleaving). The NPRM proposed 16 Hz for these parameters; the final
rule requires they be sampled and recorded at 8 Hz, and adds the
prohibition on interleaving samples.
    (2) Revise parameter 23 to correct an errant reference to part 121.
No changes were made from the language proposed in the NPRM.
    (3) The NPRM publication of the appendix included several errors in
the resolution column; none of the current resolution percentages are
being changed.

H. Part 129--Operations: Foreign Air Carriers and Foreign Operators of
U.S.-Registered Aircraft Engaged in Common Carriage

    Section 129.1, Applicability, is being amended to revise paragraph
(b) to add new Sec.  129.24 (proposed as Sec.  129.22) to the
applicability. The NPRM inadvertently omitted several section
references from this paragraph and did not account for other changes
that had been made to Sec.  129.1. The only change being adopted is the
added reference to Sec.  129.22 on CVRs.
    Section 129.24 (proposed as Sec.  129.22), Cockpit voice recorders,
is being added. This section requires that airplanes operated under
part 129 be equipped with an approved CVR that meets the standards of
TSO-C123a, or later revision, and record the information that the
airplane would be required to record if it were operated under part
121, 125, or 135, using the compliance times for the applicable part.
No change was made from the language proposed in the NPRM.

I. Part 135--Operating Requirements: Commuter and On Demand Operations
and Rules Governing Persons On Board Such Aircraft

    Section 135.151, Cockpit voice recorders, is amended to:
    (1) Add a new paragraph (f) that includes the separate container
requirements for CVRs and DFDRs on part 23 or part 25 airplanes. This
paragraph also requires transport category airplanes to meet additional
recording requirements in Sec. Sec.  23.1457 or 25.1457, as proposed in
the NPRM. The requirement to retain two hours of recorded information