Federal Register / Vol. 75, No. 33 / Friday, February 19, 2010 / Rules and Regulations 7345 

TABLE 2—AFFECTED AIRPLANES AND

ROTORCRAFT

Manufacturer 

Airbus. 

ATR—GIE Avions de Transport Re ́gional. 

The Boeing Company. 

Bombardier, Inc. 

Cessna Aircraft Company. 

Dassault-Aviation. 

Empresa Brasileira de Aeronautica S.A. 

(EMBRAER). 

Eurocopter Canada Limited. 

Eurocopter Deutschland GMBH (ECD). 

Eurocopter France. 

McDonnell Douglas Corporation. 

Subject 

(d) Air Transport Association (ATA) of 

America Code 26: Fire Protection. 

Reason 

(e) The mandatory continuing 

airworthiness information (MCAI) states: 

The Civil Aviation Authority of the United 

Kingdom (UK) has informed EASA 

[European Aviation Safety Agency] that 

significant quantities of Halon 1211 gas, 

determined to be outside the required 

specification, have been supplied to the 

aviation industry for use in fire extinguishing 

equipment. Halon 1211 (BCF) is used in 

portable fire extinguishers, usually fitted or 

stowed in aircraft passenger cabins and flight 

decks. 

EASA published Safety Information 

Bulletin (SIB) 2009–39 on 23 October 2009 to 

make the aviation community aware of this 

safety concern. 

The results of the ongoing investigation 

have now established that LyonTech 

Engineering Ltd, a UK-based company, has 

supplied further consignments of Halon 1211 

(BCF) to SICLI that do not meet the required 

specification. This Halon 1211 has 

subsequently been used to fill P/N [part 

number] 1708337B4 portable fire 

extinguishers that are now likely to be 

installed in or carried on board aircraft. 

The contaminated nature of this gas, when 

used against a fire, may provide reduced fire 

suppression, endangering the safety of the 

aircraft and its occupants. In addition, 

extinguisher activation may lead to release of 

toxic fumes, possibly causing injury to 

aircraft occupants. 

For the reason described above, this EASA 

AD requires the identification and removal 

from service of certain batches of fire 

extinguishers and replacement with 

serviceable units. 

Compliance 

(f) You are responsible for having the 

actions required by this AD performed within 

the compliance times specified, unless the 

actions have already been done. 

Actions 

(g) Within 90 days after the effective date 

of this AD, replace all Type H1–10 AIR Halon 

1211 (BCF) portable fire extinguishers 

manufactured by SICLI, having P/N 

1708337B4 and having any serial number 

listed in Table 1 of this AD, with serviceable 

fire extinguishers. 

(h) Within 90 days after doing any 

replacement required by paragraph (g) of this 

AD, return the affected fire extinguisher to: 

SICLI, ZI la Saunie`re, 89600 Saint Florentin, 

France; telephone: +33 (0)3 8643 7930; fax: 

+33 (0)3 8635 3632; e-mail 

jerome.villette@sicli.com; Web site: http:// 

www.sicli.com. 

(i) As of the effective date of this AD, do 

not install any SICLI fire extinguisher having 

P/N 1708337B4 and a serial number listed in 

Table 1 of this AD, on any airplane or 

rotorcraft. 

FAA AD Differences 

Note 1: This AD differs from the MCAI 

and/or service information as follows: 

(1) EASA AD 2009–0278, dated December 

22, 2009, specifies a time of 30 days to do 

the actions. This AD requires that the actions 

be done within 90 days. We have determined 

that a 90-day compliance time will ensure an 

acceptable level of safety. 

(2) EASA AD 2009–0278 includes fire 

extinguishers having certain serial numbers 

in its applicability. The EASA AD also 

includes a requirement to inspect to 

determine if the fire extinguishers have those 

serial numbers and replacement if necessary. 

Since the affected fire extinguishers are part 

of the applicability, it is not necessary to also 

require inspecting for them. Therefore, this 

AD includes fire extinguishers having certain 

serial numbers in its applicability and does 

not include an additional requirement to 

inspect for serial numbers; this AD requires 

replacement of all affected fire extinguishers. 

Other FAA AD Provisions 

(j) The following provisions also apply to 

this AD: 

(1) Alternative Methods of Compliance 

(AMOCs): The manager of the office having 

certificate responsibility for the affected 

product has the authority to approve AMOCs 

for this AD, if requested using the procedures 

found in 14 CFR 39.19. Before using any 

approved AMOC on any aircraft to which the 

AMOC applies, notify your principal 

maintenance inspector (PMI) or principal 

avionics inspector (PAI), as appropriate, or 

lacking a principal inspector, your local 

Flight Standards District Office. The AMOC 

approval letter must specifically reference 

this AD. 

(i) For transport airplanes: Send 

information to ATTN: Dan Rodina, 

Aerospace Engineer, International Branch, 

ANM–116, Transport Airplane Directorate, 

FAA, 1601 Lind Avenue, SW., Renton, 

Washington 98057–3356; telephone (425) 

227–2125; fax (425) 227–1149. 

(ii) For small airplanes: Send information 

to ATTN: Leslie B. Taylor, Aerospace 

Engineer, Standards Staff, Small Airplane 

Directorate, FAA, 901 Locust Street, Room 

301, Kansas City, MO 64106; telephone (816) 

329–4134; fax (816) 329–4090. 

(iii) For rotorcraft: Send information to 

ATTN: DOT/FAA Southwest Region, J.R. 

Holton, Jr., ASW–112, Aviation Safety 

Engineer, Rotorcraft Directorate, Safety 

Management Group, 2601 Meacham Blvd., 

Fort Worth, TX 76137; telephone (817) 222– 

4964; fax (817) 222–5961. 

(2) Airworthy Product: For any 

requirement in this AD to obtain corrective 

actions from a manufacturer or other source, 

use these actions if they are FAA-approved. 

Corrective actions are considered FAAapproved if they are approved by the State 

of Design Authority (or their delegated 

agent). You are required to assure the product 

is airworthy before it is returned to service. 

(3) Reporting Requirements: For any 

reporting requirement in this AD, under the 

provisions of the Paperwork Reduction Act 

(44 U.S.C. 3501 et seq.), the Office of 

Management and Budget (OMB) has 

approved the information collection 

requirements and has assigned OMB Control 

Number 2120–0056. 

Related Information 

(k) Refer to MCAI EASA Airworthiness 

Directive 2010–0278, dated December 22, 

2009, for related information. 

Material Incorporated by Reference 

(l) None. 

Issued in Washington, DC, on February 4, 

2010. 

Kalene C. Yanamura, 

Acting Director, Aircraft Certification Service. 

[FR Doc. 2010–3223 Filed 2–18–10; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Parts 121, 125, and 135 

[Docket No. FAA–2006–26135; Amendment 

Nos. 121–347, 125–59, and 135–120] 

RIN 2120–AI79 

Filtered Flight Data 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: The FAA amends digital 

flight data recorder regulations affecting 

certain air carriers and operators. This 

final rule prohibits the filtering of some 

original flight recorder sensor signals 

unless a certificate holder can show that 

the data can be accurately 

reconstructed. This final rule improves 

the integrity and quality of the data 

recorded on digital flight data recorders 

while giving aircraft designers and 

operators more flexibility in system 

design and operation where allowable. 

DATES: These amendments become 

effective April 20, 2010. 

FOR FURTHER INFORMATION CONTACT: For 

technical questions concerning this final 

rule contact Brian A. Verna, Avionics 

Systems Branch, Aircraft Certification 

Service, AIR–130, Federal Aviation 

Administration, 800 Independence 

Avenue, SW., Washington, DC 20591; 


srobinson on DSKHWCL6B1PROD with RULES
7346 Federal Register / Vol. 75, No. 33 / Friday, February 19, 2010 / Rules and Regulations 

telephone (202) 385–4643; fax (202) 

385–4651; e-mail brian.verna@faa.gov. 

For legal questions concerning this final 

rule contact Karen L. Petronis, Senior 

Attorney for Regulations, Regulations 

Division, Office of the Chief Counsel, 

AGC–200, Federal Aviation 

Administration, 800 Independence 

Avenue, SW., Washington, DC 20591; 

telephone (202) 267–3073; fax 202–267– 

7971; e-mail karen.petronis@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Authority for This Rulemaking 

The FAA’s authority to issue aviation 

safety rules 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. 

I. Background 

A. Statement of the Problem 

During several aircraft accident 

investigations, the National 

Transportation Safety Board (NTSB) 

found that some flight data recorder 

systems were filtering flight recorder 

sensor signals before they were 

recorded. As a result, the recorded data 

did not accurately reflect the aircraft’s 

performance or the movements of the 

flight control systems before and during 

the accident or incident under 

investigation. Such signal filtering both 

hampered and delayed the 

investigations. Throughout the 

investigation of American Airlines 

Flight 587 (Flight 587), which crashed 

after takeoff from John F. Kennedy 

Airport, Jamaica, New York in 

November 2001, the NTSB expended 

significant time and resources trying to 

recreate the performance and 

movements of the flight controls of the 

accident aircraft. 

In November 2003, the NTSB issued 

three recommendations (NTSB 

Recommendations A–03–48/A–03–49/ 

A–03–50, November 6, 2003) on digital 

flight data recorder (DFDR) recording 

requirements. The NTSB recommended 

that the FAA require all aircraft to have 

a DFDR system installed ‘‘capable of 

recording values that meet the accuracy 

requirements through the full dynamic 

range of each parameter at a frequency 

sufficient to determine a complete, 

accurate, and unambiguous time history 

of parameter activity, with emphasis on 

capturing each parameter’s dynamic 

motion at the maximum rate possible, 

including reversals of direction at the 

maximum rate possible.’’ 

B. Action by the FAA—Notice of 

Proposed Rulemaking 

In 2006, the FAA issued a notice that 

proposed a prohibition on filtering 

certain original flight data sensor signals 

(November 15, 2006, 71 FR 66634). The 

2006 NPRM contains a complete 

discussion of the proposal and the 

events leading up to it. 

The comments received in response to 

the 2006 NPRM alerted the FAA to 

several features of the proposed 

prohibition that would have had 

significantly more impact than the 

agency had expected. The issue that 

produced the most comment was the 

proposed definition of filtering, which 

described filtering as a change to any 

original sensor signal for any reason 

other than the three specified in the 

proposal. The comments indicated that 

the level of signal processing that is in 

use on newer flight data systems no 

longer corresponds to more traditional 

concepts of filtering, and leaves in 

question whether current system 

designs would be considered to be 

filtering data before recording. 

As the FAA considered changes to the 

definition of filtering, the agency 

continued studying what is quickly 

becoming the standard in electronic 

signal processing. Our intent in the 2006 

NPRM was to prohibit the processing of 

certain flight data sensor signals that 

would result in inaccurate data being 

preserved, as happened with the rudder 

movement data on Flight 587. 

The investigation following the crash 

of Flight 587 indicated that the issue 

was not that data were filtered, but that 

the actual rudder movement data could 

not be reconstructed once processed by 

installed filtering devices. While a 

prohibition like our 2006 proposal 

would solve the problem, current 

capabilities suggested that when 

properly processed and documented, 

data can be reconstructed from a system 

design that incorporates filtering. 

C. Action by the FAA—Supplemental 

Notice of Proposed Rulemaking 

The determination that flight recorder 

systems from which data may be 

reconstructed were acceptable exceeded 

the scope of the changes in the 2006 

NPRM. Accordingly, the FAA issued a 

supplemental notice of proposed 

rulemaking (August 15, 2008, 73 FR 

47857)(SNPRM). The SNPRM proposed 

that recording of filtered flight data be 

allowed if a certificate holder could 

demonstrate that the ‘filtered’ recorded 

data meet the recording requirements of 

the regulations, and that the original 

sensor signal data could be accurately 

reconstructed using a documented, 

repeatable process. 

In the SNPRM, the FAA changed its 

position from a strict filtering 

prohibition to one of conditional 

allowance that distinguishes between 

two groups of flight recorder 

parameters. The first group contained 

those that are prohibited from being 

filtered unless a certificate holder can 

demonstrate that it has done the tests 

and analyses and maintains the 

procedures necessary to reconstruct the 

original sensor signal values from the 

filtered recorded data. The second group 

included those parameters whose 

signals may be filtered without further 

action as long as they meet the 

requirements of the regulations. 

The option not to filter any or all 

parameters remained an acceptable 

means of compliance with the 

regulations. In all cases, the accuracy 

and all other requirements of Appendix 

M of part 121 (or Appendix E of part 

125 or Appendix F of part 135) must 

continue to be met. The ability to 

reconstruct data would not forgive any 

appendix requirement for any 

parameter. 

The proposed time for compliance in 

the SNPRM was four years after the 

effective date of the final rule. Within 

that four-year period, one of two things 

was to happen. 

If an operating certificate holder 

elected not to filter any of the restricted 

parameters, it had four years to test its 

DFDR systems, verify that none of the 

restricted parameters are being filtered, 

or, if a restricted parameter is being 

filtered, modify that parameter to 

eliminate the filtering. 

If a certificate holder chose to filter a 

restricted parameter and show by test 

and analyses that the originating signal 

can be reconstructed, the procedures for 

reconstruction would have to be 

submitted to the FAA after the next 

heavy maintenance check of an airplane 

(beginning six months after the effective 

date of the final rule), but not later than 

two years after the effective date of the 

final rule. If a certificate holder has 

several of the same make, model and 

series airplane (group) with the same 

certificated DFDR system installed, the 


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procedures need only be submitted once 

for the entire group of airplanes with 

identically installed systems. The 

compliance date for a group would be 

tied to the first airplane going in for a 

heavy maintenance check six months 

after the rule is final. Submission of the 

data to the FAA would be required no 

later than the time the first airplane of 

a group completes that heavy 

maintenance check. 

This compliance schedule was 

intended to allow time for the FAA to 

determine that the submitted 

reconstruction procedures are 

repeatable, but still allow time for other 

compliance action (within the four 

years) if repeatability was not 

accomplished. A certificate holder that 

was unable to show repeatability for any 

restricted parameter would be required 

to modify the parameter to eliminate 

filtering before the four year compliance 

period ends. 

We did not include in the rule text a 

time limit for submission of the 

reconstruction procedures to the NTSB 

following an accident or occurrence that 

requires the NTSB be notified. We 

presumed that the reconstruction data 

are included as part of the recorder and 

its data that are subject to § 121.344(i) 

and the NTSB’s authority under 49 CFR 

part 830. We invited comment on 

whether a specific, brief time for 

submission needs to be included 

separately in the rule for the 

reconstruction procedure data. 

The SNPRM contains a more 

complete discussion of the proposal. 

Following publication of the SNPRM, 

industry members contacted the FAA 

indicating that the economic evaluation 

did not reflect the effect of the proposed 

rule language. The SNPRM stated that a 

certificate holder could not filter data 

unless the recorded values complied 

with Appendix M and the certificate 

holder possessed procedures to 

reconstruct original sensor signals. The 

FAA had intended to propose rule 

language that applies to certain 

parameters if the recorded values do not 

comply with Appendix M. If Appendix 

M requirements are not met, then the 

certificate holder would have the choice 

to either remove the filtering or show by 

test and analysis that the original, 

unfiltered values can be successfully 

reconstructed to meet the requirements 

of Appendix M. On November 13, 2008, 

we amended the SNPRM (73 FR 67115) 

by publishing a correction and 

extension of the comment period until 

December 29, 2008. 

II. Discussion of Comments to the 

SNPRM 

A. General Summary 

The FAA received eight comments 

covering more than 30 issues in 

response to the SNPRM. The NTSB 

generally agreed with the proposed rule 

and urged adoption of a final rule. 

Airbus, Boeing Commercial Airplanes 

(Boeing), the Regional Airlines 

Association (RAA) and Astar Air Cargo, 

Inc. (Astar) agreed on the importance of 

recording unfiltered, accurate data, but 

did not agree with the SNPRM’s 

approach to accomplish this goal. The 

General Aviation Manufacturers 

Association (GAMA) agreed with the 

rule as proposed and provided 

supplemental cost information. Two 

individual commenters expressed 

support for the rule as proposed. 

B. Parameters Covered by the Filtering 

Prohibition 

In the SNPRM, the FAA used the 

commenters’ term ‘‘no filter list’’ to 

describe those parameters prohibited 

from being filtered. While not entirely 

accurate, the FAA continues to use ‘‘no 

filter list’’ when discussing these 

comments to prevent further confusion. 

The SNPRM proposed the same ‘‘no 

filter list’’ as the 2006 NPRM with the 

addition of 14 parameters requested by 

the NTSB in its 2006 comment. The 

FAA included these additional 

parameters in proposed § 121.346(b)(1) 

because the NTSB stated that they 

would provide valuable data during 

accident investigation and should not be 

filtered. 

Airbus and Boeing asked that the FAA 

remove all parameters from the ‘‘no filter 

list’’ except parameters 12–17 and 88 

based on the complexity of current 

filtering techniques and the cost burden 

to industry associated with FDR system 

modifications. They cited specific cases 

where aircraft systems (such as an air 

data computer and an air data inertial 

reference unit) process data from 

multiple sources to be transmitted 

through an ARINC 429 data bus, and to 

be used by other aircraft systems, 

including the DFDR. Airbus identified 

parameters 2, 3, 4, 6, 7, 9, 26, 32, 42, 43, 

and 70 as coming from these multiple 

source systems. Boeing provided general 

information that supported the Airbus 

comment, and noted that significant 

cost and effort would be required to 

revise multiple aircraft systems to 

comply with the proposed rule. Airbus 

also raised the modification cost issue, 

although it did not provide any 

supporting cost data for the 11 

parameters it suggested be removed 

from the proposed list. Boeing noted 

that it was not aware of any 

investigation that had been adversely 

affected by filtered data from the 

parameters it suggested be excluded, 

and thus could find no safety benefit 

that would balance the cost of the 

system revision. 

Boeing provided specific information 

supporting its request to remove the 

parameters for heading (number 4) and 

engine thrust (number 9) from the ‘‘no 

filter list.’’ Boeing noted that the 

Appendix M requirements for these two 

parameters indicate that the recorded 

values are to come from the primary 

flight crew reference. These data are 

smoothed for readability when 

displayed to the flight crew. Their being 

filtered is required in the appendices to 

parts 121, 125, and 135, and thus should 

not be included in the ‘‘no filter’’ list. 

Boeing and Airbus stated that the 

acceleration outputs, parameters 5, 8, 

and 18, should not be included in the 

‘‘no filter list.’’ They argued that ARINC 

Characteristic 717 ‘‘Flight Data 

Recording and Recording Systems’’ 

specifies that accelerometer outputs be 

filtered in order to provide accurate and 

readable data to the DFDR. They stated 

that removing the ARINC-specified 

filtering would result in erroneous 

acceleration data due to aircraft 

vibration. 

The FAA agrees with Boeing and 

Airbus that the parameters covered by 

the prohibition should be limited to 

flight control surface positions, flight 

control input positions and flight 

control input forces. Since parameters 1 

through 4, 6, 7, 9, 26, 32, 43, 68, 70, and 

77 are non-flight control parameters and 

are slower-changing parameters 

sampled at less than 4 Hertz (Hz), they 

are not negatively affected by filtering. 

Additionally, the FAA agrees with 

Boeing and Airbus regarding parameters 

5, 8, and 18. Although these are more 

quickly changing parameters, without 

the filtering specified by ARINC 717, the 

accelerometers would provide 

unreadable data. The FAA has 

determined that there is no safety 

benefit in requiring reconstruction of 

the original sensor signal values for 

these parameters, and that the impact on 

industry would have been significantly 

greater than the FAA anticipated when 

they were proposed for inclusion. 

The FAA has not changed its position 

on parameter 42 (throttle lever angle). 

Although it is only required to be 

sampled at 1 Hz, parameter 42 is a 

critical flight control input position 

parameter and remains subject to the 

filtering restriction. 

Accordingly, the final rule does not 

restrict the filtering of the non-flight 

control parameters as discussed above. 


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Further, the FAA agrees with Boeing 

regarding the recording of primary flight 

crew reference for parameters 4 and 9, 

and the two parameters are not included 

in the filtering prohibition in the final 

rule. 

C. Filtered Flight Data Signal Definition 

In the SNPRM, the FAA proposed that 

a flight data recorder signal is 

considered filtered when an original 

sensor signal is changed in any way, 

other than changes necessary to: 

(1) Accomplish analog to digital 

conversion of the signal, 

(2) Format a digital signal into a DFDR 

compatible format; or 

(3) Eliminate a high frequency 

component of a signal that is outside the 

operational bandwidth of the sensor. 

Boeing requested an expansion of this 

definition that would allow the 

averaging of two or more data samples 

acquired at the same point in time from 

different sensors, which would provide 

the best available representation of that 

parameter. 

Boeing and Airbus each 

recommended changes to the term 

‘‘original sensor signal.’’ Airbus 

recommended replacing it with the term 

‘‘signal output from the original sensor 

system.’’ Boeing recommended defining 

a sensor as a device that perceives 

deviations from a reference and converts 

them into signals or information that 

can be used by systems on the airplane. 

Boeing added that a sensor can be a 

system that accepts information from 

multiple points of measurement and 

processes this information into data 

useable by other airplane systems. 

While the FAA disagrees with 

Boeing’s request to expand the 

definition of a filtered flight data signal, 

the agency agrees with Boeing and 

Airbus that the concept of what 

constitutes an original sensor signal can 

be expanded within the regulatory 

definition. To address these concerns, 

material from the commenters will be 

incorporated as examples in FAA 

Advisory Circular 20–141B 

‘‘Airworthiness and Operational 

Approval of Digital Flight Data Recorder 

Systems.’’ 

The FAA agrees with Boeing and 

Airbus that an original sensor signal can 

come from either a single sensor or a 

system that accepts multiple sensor 

inputs to provide accurate information 

to other aircraft systems. For example, 

the FAA does not consider it necessary 

to record every ring laser gyroscope 

input into the electronic flight 

instrument system, nor to directly 

record the output of an unfiltered 

accelerometer. The signal conditioning 

and filtering techniques used to record 

parameters 2, 3, 4, 6, 7, 9, 26, 32, 43, 

and 70 are necessary to provide accurate 

data for several aircraft systems, only 

one of which is the flight recorder 

system. The redesigning of aircraft 

critical systems or the significant 

alteration of current instruments from 

which data are gathered was not the 

intent of the proposed rule, and would 

be outside the scope of this rulemaking. 

D. Reconstruction of Filtered Data 

Shortly after the close of the comment 

period for the 2006 NPRM, the FAA 

learned of technological developments 

that would allow the reconstruction of 

data that had been filtered before they 

were recorded. The FAA determined 

that this option should be made 

available to operators rather than the 

simple prohibition proposed in the 2006 

NPRM. That decision led to the 

publication of the SNPRM in 2008, 

which proposed to allow filtering if data 

could be reconstructed, and requested 

comment on several issues related to the 

ability to reconstruct. 

Boeing commented that, with regard 

to parameters that are sampled at one 

second or slower, reconstruction would 

be both ‘‘unrealistic and problematic’’ 

and suggested that the option of 

reconstruction not be included in the 

final rule. Boeing noted that for some 

parameters, the data are conditioned at 

the microsecond level. When sampled at 

once per second, the conditioned inputs 

are nonexistent and not subject to 

reconstruction. 

The FAA understands Boeing’s 

concern and agrees that, under the 

circumstances stated, the data would 

not be available for reconstruction. The 

agency presumes from Boeing’s 

comment that its position is based on 

the assumption that the conditioned 

data would be considered filtered under 

the FAA’s proposed definition, making 

it both subject to the prohibition yet 

impossible to reconstruct. However, 

from the examples presented to the FAA 

by Boeing, the type of conditioning 

taking place would not be considered 

filtering under the proposed definition, 

and thus not subject to the prohibition 

or the reconstruction option. The option 

to reconstruct filtered data remains in 

this final rule. The reconstruction of 

filtered flight data has been proven to be 

effective for rapidly changing 

parameters (sampled at four or more 

times per second). 

Astar noted that the requirement to 

maintain DFDR data appears in 

§ 121.344(i), while the filtering 

requirement is being moved to new 

§ 121.346. Astar commented that the 

separation of the requirements makes 

the proposed language (including the 

phrase ‘‘of this section’’) inaccurate. 

The FAA agrees. The new 

§ 121.346(c)(2)(ii) references § 121.344(i) 

as a requirement for reconstruction 

documentation. 

The GAMA requested that the FAA 

provide further guidance regarding the 

type of documentation an operator must 

possess to demonstrate compliance with 

the proposed regulation. The GAMA 

noted that part 135 operators generally 

do not operate large fleets of similar 

airplanes, and thus a simple approach to 

documentation is needed. 

The FAA agrees on the need for 

simple compliance documentation. As 

discussed in more detail below, each 

operator will be responsible for creating 

a record for each of its airplanes 

indicating its compliance status with 

this rule, including a reference to any 

parameters being filtered. The FAA 

anticipates that much of this analysis 

will be available from the original 

equipment manufacturers. A record of 

each airplane’s status regarding filtering 

is to be maintained as part of the flight 

data recorder correlation documentation 

already required. Compliance with the 

requirements for reconstruction data, 

including record maintenance, will be 

more complex if filtering is found and 

the reconstruction option is chosen. 

Detailed information regarding the 

content and maintenance of that data 

will be available in FAA Advisory 

Circular 20–141B ‘‘Airworthiness and 

Operational Approval of Digital Flight 

Data Recorder Systems.’’ 

E. Appendix M 

1. Introductory Text 

In both the 2006 NPRM and 2008 

SNPRM, the FAA proposed the 

following language to clarify ‘‘dynamic 

condition’’ as used in the introductory 

text to part 121 Appendix M (and 

comparable appendices in other parts): 

‘‘Dynamic condition means the 

parameter is experiencing change at the 

maximum rate available, including the 

maximum rate of reversal.’’ 

In its comments on both proposals, 

the NTSB requested the language be 

revised to state the ‘‘maximum rate 

possible.’’ The NTSB stressed the 

importance of having recording systems 

capable of accurately recording motion 

rates typically experienced during an 

accident sequence. 

In its comment to the SNPRM, Boeing 

requested that the language be 

eliminated. Boeing stated that the 

prohibition in proposed § 121.346 

eliminates the need for the introductory 

text in the appendices. In the 

alternative, Boeing suggested that the 


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introductory text be revised to read: 

‘‘[d]ynamic condition means the 

parameter is experiencing change at the 

maximum rate the source system can 

cause by design, including the 

maximum rate of reversal.’’ Boeing 

interprets dynamic condition to be both 

fundamental to the design of and unique 

to the function of each aircraft system. 

Airbus requested that the introductory 

text be revised to read: ‘‘[d]ynamic 

condition means the parameter is 

experiencing change at the maximum 

rate under operational conditions, 

including maximum rate of reversal.’’ 

Airbus was concerned that the proposed 

language went beyond the operational 

limits of actual systems, and further 

suggested that the language be moved 

from the appendix to § 121.344. 

The FAA has decided that the 

introductory text of the appendices will 

refer to the ‘‘maximum rate attainable.’’ 

Following much debate, the term 

attainable appears to satisfy the 

commenters’ concerns, including the 

design limitations of a specific source 

system. 

In the SNPRM, the FAA noted that the 

NTSB did not provide any rationale for 

its suggested change to ‘‘maximum rate 

possible’’ and the agency could not 

conclude that it was an improvement. 

Since the word ‘‘possible’’ could be 

interpreted to include states that are 

well beyond the operational range of 

equipment, the suggested change 

appeared inappropriate as a regulatory 

standard. 

Additional guidance will be included 

in FAA Advisory Circular 20–141B 

‘‘Airworthiness and Operational 

Approval of Digital Flight Data Recorder 

Systems.’’ 

Finally, the FAA does not agree that 

the introductory text should be 

relocated to § 121.344. The text refers to 

requirements for each parameter as 

listed in the appendix. Separating it 

from the appendix requirements would 

cause unnecessary confusion. 

2. ‘‘Accuracy (Sensor Input)’’ Column in 

Appendix M 

Boeing stated that the appendix 

column titled ‘‘Accuracy (Sensor input)’’ 

is ambiguous in terms of what 

constitutes accuracy and how accuracy 

is measured. Boeing submitted its own 

definition of the term ‘‘accuracy’’ based 

on its suggested definition of the term 

‘‘sensor’’ (discussed above). Boeing 

described its understanding of accuracy 

as being the relationship between the 

actual entity being measured and the 

recorded position of that entity within 

a stated range. 

Airbus requested that the FAA 

provide values for the maximum 

dynamic error allowable for each 

parameter in the appendices. Airbus 

added that the amount of dynamic error 

is dependent on the sampling rate and 

the operational condition of an 

individual aircraft. 

The FAA disagrees with adding a 

definition of accuracy or adding 

maximum dynamic error in the 

appendices. The accuracy column has 

been present in the regulation since its 

adoption in 1997 and has not been an 

identified source of confusion. Further, 

the FAA did not propose any changes to 

accuracy specifications, making these 

suggested changes outside the scope of 

this rulemaking. Except for the change 

to the term ‘‘maximum rate attainable’’ 

in the introductory text, no other 

changes to the appendices are being 

adopted in this final rule. The FAA will 

expand its discussion of how accuracy 

is measured in the update to the 

advisory circular material based on 

material submitted by the commenters. 

3. Expansion of Appendix M 

Boeing requested that Appendix M 

include a table defining each 

parameter’s primary and secondary 

purposes, whether or not it should be 

filtered, and from what source it should 

be recorded. 

The FAA considers an additional 

table in Appendix M to be inappropriate 

and beyond the scope of this 

rulemaking. Other than a clarification of 

the language in the introductory text, no 

changes to Appendix M were proposed. 

Compliance with Appendix M remains 

unchanged. 

Astar requested that the parameters 

affected by this rule be identified by an 

additional column in the appendices. 

Astar also found the placement of the 

filtering prohibition in § 121.346 (rather 

than § 121.344) to be misleading. 

The FAA does not agree with Astar 

that an additional column in the 

appendices is necessary. The filtering 

prohibition was moved to a separate 

regulatory section in order to highlight 

its importance and prevent it from being 

overlooked in the extensive 

requirements already present in 

§ 121.344. No changes have been made 

based on this comment. 

F. Applicability 

1. Existing and Newly Manufactured 

Aircraft 

In the SNPRM, we proposed that the 

filtered flight data prohibition apply to 

both existing and newly manufactured 

aircraft. Airbus and the RAA agreed 

with the approach to allow filtering if an 

operator can demonstrate accurate, 

repeatable reconstruction of an original 

sensor signal. However, they stated that 

any final rule should only apply to 

newly manufactured airplanes or 

airplanes on which Supplemental Type 

Certificate (STC) changes to the flight 

recorder system have been installed. 

Airbus noted that such application of 

the rule would be less costly since 

manufacturers would be able to 

combine new designs into other flight 

recorder system improvements. 

The RAA stated that the safety 

concerns raised by the FAA are issues 

applicable to the design and 

certification processes, making the 

solution better suited to be applicable 

only to newly manufactured airplanes. 

As we stated in the 2006 NPRM and 

the SNPRM, the FAA considered the 

regulatory alternative of limiting the 

filtering prohibition to newly 

manufactured aircraft. While this 

approach is always less costly than a 

rule that affects the in-service fleet, it 

would also fail to address the aircraft 

currently operating with flight recorder 

systems that filter critical flight data 

before recording it. The FAA is also 

concerned that failing to cover inservice aircraft could lead to more 

filtering, which could result from future 

system modifications on in-service 

aircraft not subject to the prohibition. 

Experience has shown that filtering 

has caused problems during accident 

investigations. The FAA disagrees that 

the reconstruction efforts during the 

investigation of Flight 587 had an 

acceptable outcome. The NTSB has not 

released any formal opinion that the 

results from the Flight 587 data 

reconstruction were satisfactory, or that 

the processes involved in that data 

reconstruction were acceptable. The 

FAA recognizes that data 

reconstruction, when satisfactory from 

an accuracy standpoint and shown to be 

repeatable, is an acceptable alternative 

and has included it in this final rule. 

However, the agency cannot conclude 

that the problems uncovered by the 

Flight 587 investigation have been 

solved. Allowing airplanes to remain in 

the fleet while filtering critical data is 

not an acceptable alternative. Without 

this rule, there would be no requirement 

to develop and maintain accurate, 

repeatable processes for reconstructing 

data that are filtered before being 

recorded. 

2. A300/A310 Airplanes 

Airbus stated that on its A300–600 

and A310 airplanes, parameters 15, 16, 

17, and 19 are filtered under our 

proposed definition. Airbus noted that 

the filter conversion algorithms have 

been solved for the A300/A310 

airplanes, concluding that the problem 


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will not occur again, unless a customer 

has chosen to change the recording 

system through an STC. 

Astar stated its understanding that the 

FAA’s reference to the A300 in the 

SNPRM is to the A300–600 model. Astar 

added that it operates the A300–B4B 

model airplane and has not identified 

data filtering during its review of 

research and engineering 

documentation. Astar requested that the 

final rule include a list of those aircraft 

that are not covered by the rule. 

The RAA stated that there had to be 

‘‘a more cost effective way to identify 

the DFDR’s of concern without having 

every certificate holder ‘‘recertify’’ their 

product.’’ The RAA also stated that since 

‘‘the FAA has the certification data for 

the DFDR systems for all airplane types 

in operation,’’ the agency should be able 

to determine specific aircraft types that 

‘‘need not be recertified to the new 

standards.’’ 

As discussed above, the FAA finds it 

unacceptable to limit the applicability 

of this rule as suggested. The FAA does 

not know the identity of all models or 

the total number of airplanes that may 

be recording filtered data, and thus has 

no rational basis to restrict applicability. 

The FAA does not possess the 

engineering documentation required to 

evaluate the DFDR systems of all 

airplanes currently in operation. The 

requirement for each operator to assess 

the function of its airplanes with regard 

to filtering is a critical facet of this rule. 

This effort is not a recertification, as 

suggested. It is first a determination of 

system function. Once that 

determination is made, and if filtering is 

found, the operator will have the choice 

of how to comply with this rule. The 

FAA cannot ignore the possibility of an 

in-service airplane filtering critical data 

simply because the model is no longer 

in production. Similarly, limited 

applicability leaves open the possibility 

of future filtering by modifications made 

on airplanes that were not filtering 

when the rule took effect. The 

applicability of this final rule is adopted 

as proposed. 

3. Part 91 Airplanes 

The GAMA stated that the proposed 

regulation would have a significant cost 

and burden impact on the owners and 

operators of aircraft that are equipped 

with DFDRs as required under § 91.609. 

The GAMA noted that it is typical for 

an aircraft that operates under part 135 

to begin and end its operating life cycle 

under part 91. For aircraft equipped 

with a flight recorder operating under 

part 91 and 135, the GAMA estimated 

that between 1,125 and 5,600 aircraft 

could be affected, resulting in a 

$2,000,000 to $9,000,000 impact on the 

general aviation community for no 

measurable benefit. 

Neither the 2006 NPRM nor the 

SNPRM proposed any changes to part 

91 requirements. The FAA cannot 

predict and would not have any basis 

for presuming how many or which 

airplanes might change operating parts, 

or who would be operating them. In 

addition, the costs of complying with 

this rule would be minimal when 

compared to the significant differences 

between part 91 and part 135 operating 

requirements overall. No change to the 

regulations is being made based on this 

comment. 

G. Compliance Time 

The SNPRM included a compliance 

time from six months to two years for 

an operator to develop, validate, and 

submit filtered data reconstruction 

procedures to the FAA. The proposed 

rule included a final compliance time of 

four years for airplanes manufactured 

up to 18 months after the effective date 

of a final rule. 

Astar commented that the compliance 

time in the 2006 NPRM appears to be 

different from that in the SNPRM, and 

suggests that the time for demonstrating 

that an airplane’s flight data recorder 

system is not filtering data is confusing. 

The FAA understands the 

commenter’s concerns and has 

reconsidered the language of the 

compliance time paragraph. The final 

rule includes the following compliance 

requirements. 

Operators will have 18 months from 

the effective date of this rule (referenced 

in this discussion as the reporting date) 

to review their DFDR systems and create 

a record that indicates whether the 

DFDR system on each airplane is 

filtering any of the parameters included 

in the ‘‘no filter list.’’ If any of those 

parameters are being filtered, the record 

must also indicate which are affected. If 

no parameters are being filtered, that 

record entry should be made at the time 

of the determination, and an operator 

need take no further action unless a 

change is made to a DFDR system. 

Records of this action are to be 

maintained as part of the flight data 

recorder correlation documentation 

already required by the regulations. 

Operators that identify filtered 

parameters will have two options. If an 

operator chooses to remove the filtering, 

it has four years from the effective date 

(thirty months after the reporting date) 

to make the system modifications. If an 

operator chooses to demonstrate by tests 

and analyses that filtered data can be 

reconstructed, the operator has up to 18 

months from the reporting date to 

submit its reconstruction package to the 

FAA for approval. This submission date 

accounts for the time needed for the 

FAA to review the tests and analyses 

and verify their repeatability. 

In all cases, compliance with the rule 

is required four years from the effective 

date. In no case will the submission of 

reconstruction tests and analyses be 

considered compliance until that 

submission is approved by the FAA. 

Operators that choose that method of 

compliance are cautioned to submit 

their tests and analyses as early as 

possible in case their submissions fail to 

be approved and other action need be 

taken. 

Operators may submit material from 

manufacturers for all showings required. 

However, for all ‘group’ submissions (all 

airplanes of a particular model, for 

example), the operator must indicate in 

its records that the manufacturer’s 

verifications apply to a particular 

airplane’s DFDR system and that the 

airplane’s DFDR system has not been 

modified to remove it from the group 

characteristics with regard to data 

filtering. Entries must be made for 

individual airplanes, not for models as 

a group. The record must be maintained 

as part of the flight data recorder 

correlation documentation already 

required by the regulations. 

These compliance times provide 

ample opportunity for certificate 

holders to make choices about their 

equipment and conduct any necessary 

analyses during a regularly scheduled 

heavy maintenance visit, reducing 

potential impact on scheduled 

operations or additional out-of-service 

time. Much of the initial work in 

determining whether filtering is present 

on restricted parameters does not 

require physical access to airplane 

systems, but may be determined by 

reference to the airplane’s DFDR system 

engineering and maintenance 

documentation. 

H. Cost/Benefit Analysis 

In the regulatory evaluation for the 

2008 SNPRM, the FAA estimated it 

would cost certificate holders a total of 

$28,160 to undertake a review of DFDR 

systems documentation to determine 

whether filtering were taking place. The 

FAA stated that it was unable to 

estimate any further impact of the 

proposed rule, since we had no data 

indicating the number of airplanes in 

the fleet that were filtering data, nor 

how much it would cost in any instance 

to correct. Commenters provided some 

cost information, as discussed below, 

but none provided data related to 

developing reconstruction procedures. 


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1. Airbus A300/A310 Retrofit Costs 

Airbus estimated that, for its A300/ 

A310 fleet, the engineering costs to 

correct the recording of filtered data for 

parameters 12 through 17 and 88 would 

be about $750,000. In addition, 

equipment to make each airplane 

compliant with the rule would cost 

between $25,000 and $40,000 per 

airplane, for a total of $26 million to $46 

million for the U.S. Airbus fleet. Airbus 

indicated that these were costs of this 

proposal. 

The FAA reiterates the findings from 

the SNPRM that the cost to correct the 

DFDR systems on the Airbus A300/310 

to comply with the existing Appendix 

M requirements is not a cost of this rule. 

Even though the 1997 regulations do not 

specifically prohibit filtering, the Flight 

587 investigation discovered that the 

airplane’s recorded data did not meet 

the accuracy performance requirements 

of Appendix M. Consequently, the 

compliance cost estimated by Airbus is 

the cost of complying with Appendix M, 

which has been in effect since 1997. 

This compliance cost would be incurred 

whether we had ever proposed a rule 

change regarding filtering because the 

aircraft did not comply with Appendix 

M. This rule does not change 

compliance with Appendix M. It simply 

provides an option of how compliance 

may be met: whether the data are 

recorded unfiltered or are filtered and 

can be reconstructed. 

2. Original Equipment Manufacturer 

Versus Operator Costs 

Boeing stated that many operators 

would not be able to determine which 

parameters are filtered. Boeing added 

that the operators depend on the 

manufacturer to identify conditioned 

parameters and provide reconstruction 

procedures, if applicable. Boeing 

requested that the FAA account for 

these costs in the regulatory evaluation. 

The FAA agrees that operating 

certificate holders would be expected to 

consult with the original manufacturers 

of their equipment to identify which (if 

any) DFDR parameters are being filtered. 

The list of parameters that must be 

evaluated is now limited to flight 

control surface positions, flight control 

input positions, flight control forces, 

and throttle lever position. The effort 

needed to identify whether any of these 

eight parameters are being filtered under 

the regulatory definition is included in 

the regulatory evaluation. The cost is 

assessed on the operator. 

I. Changes Made Through Operating 

Rules 

Astar agreed with Air Tran’s 2006 

comment that it is improper to use the 

operating rules of part 121 to impose 

technical requirements unique to a 

specific model of aircraft or unique to 

the design of an aircraft system. Astar 

noted that operators are not typically 

involved with the engineering of aircraft 

systems, and usually do not install or 

alter components. It considers data 

filtering to be a function of the DFDR 

system design and not the responsibility 

of the operators. 

The FAA’s position has not changed 

since responding to AirTran’s comment 

in the 2008 SNPRM. The DFDR 

requirements are part of the operating 

rules. The only effective way to 

implement changes to in-service aircraft 

is through the operating rules, since the 

certification rules generally are not 

retroactive and do not include the 

specific requirements. This rule makes 

specific changes to certain flight 

recorder parameters, and those 

parameters exist as part of the 

regulations in parts 121, 125, and 135. 

A change made to the certification rules 

would not affect aircraft in service. 

J. Miscellaneous Comments 

1. DFDR System Review 

Astar noted that the SNPRM stated if 

a certificate holder elects not to filter 

any of the restricted parameters, it has 

four years to test its DFDR systems and 

verify that none of the restricted 

parameters are being filtered. Astar 

stated that § 121.346(c) does not 

indicate that a certificate holder should 

test the DFDR system to confirm 

whether a parameter is filtered or not. 

Astar requested that the FAA remove 

the explanation of a DFDR system test 

when a review of engineering and 

maintenance documentation could be 

used to identify parameters that are 

filtered. 

The FAA agrees that the SNPRM did 

not include a requirement for a 

certificate holder to test its DFDR 

system to confirm whether a parameter 

is filtered. The final rule includes a 

requirement for operators to review 

their DFDR systems and create a record 

that includes each of its airplanes 

indicating whether and which 

parameters are being filtered. The 

system review information may be 

acquired from the equipment 

manufacturer and a physical system test 

may not be necessary. If filtering is 

found, the means of compliance with 

this rule is also the choice of the 

operator. 

2. Compliance Decision Diagram 

Airbus submitted a complex decision 

diagram that illustrates its 

understanding of the proposed rule. 

Airbus stated that if the FAA did not 

agree with the logic of the diagram, 

Airbus would be unable to provide cost 

information associated with each 

parameter. 

The FAA does not agree with the logic 

that underlies Airbus’s decision 

diagram. Moreover, changes adopted in 

this final rule significantly affect 

Airbus’s decision diagram. As will be 

detailed in the FAA’s decision diagram 

in AC 20–141B, there is a 

straightforward approach to evaluating 

the parameters. First, only those 

parameters listed in § 121.346(c) need 

be evaluated to determine whether they 

are being filtered under the regulatory 

definition. Next, the certificate holder 

must determine if the recorded data 

meet the accuracy requirements of 

Appendix M. If they do not, the 

certificate holder needs to decide 

whether to attempt data reconstruction, 

or alter the DFDR system to record 

unfiltered data. 

III. Final Rule Language 

The structure of the final rule 

language differs from the proposals. In 

the proposed rules, we differentiated the 

group of parameters that could be 

filtered from those that could not. That 

distinction is no longer relevant. 

Using part 121 as the example, 

§ 121.346(a) contains the definition of 

filtering. Paragraph (b) states that any 

parameter may be filtered as long as the 

recorded value meets all of the 

requirements of Appendix M. Paragraph 

(c) specifies the eight critical flight 

control parameters discussed, and 

indicates that if any of those parameters 

are filtered, and because of the filtering 

does not meet the requirements of 

Appendix M, then the compliance 

option of reconstruction described in 

(c)(1)–(2) is available. A critical 

parameter that fails to meet Appendix M 

for some reason other than filtering that 

can be rectified by reconstruction is 

considered a violation of Appendix M 

and is not allowed under any part of the 

regulation. 

This means that if any of the critical 

parameters is being filtered but 

nonetheless meets the requirements of 

Appendix M, no action is required. This 

is true for all other parameters as well. 

The only parameters not required to 

meet the Appendix M requirements are 

the eight critical ones, and then only if 

they can be satisfactorily reconstructed 

as required under paragraph (c) to meet 

Appendix M requirements. 


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1 GRA, Incorporated, Economic Values for FAA 

Investment and Regulatory Decisions, A Guide, 

Final Report, September 30, 2008, Table 7–1A: 2008 

Mean Burdened Hourly Labor Rates of Aeronautical 

Engineers and Aviation Mechanics, p. 7–3. 

IV. Regulatory Notice and Analysis 

Paperwork Reduction Act 

As required by the Paperwork 

Reduction Act of 1995 (44 U.S.C. 

3507(d)), the FAA has submitted the 

information requirements associated 

with this proposal to the Office of 

Management and Budget for its review. 

According to the 1995 amendments to 

the Paperwork Reduction Act (5 CFR 

1320.8(b)(2)(vi)), an agency may not 

collect or sponsor the collection of 

information, nor may it impose an 

information collection requirement 

unless it displays a currently valid OMB 

control number. The OMB control 

number for this information collection 

will be published in the Federal 

Register, after the Office of Management 

and Budget approves it. 

International Compatibility 

In keeping with U.S. obligations 

under the Convention on International 

Civil Aviation, it is FAA policy to 

comply with International Civil 

Aviation Organization (ICAO) Standards 

and Recommended Practices to the 

maximum extent practicable. The FAA 

has determined that there are no ICAO 

Standards and Recommended Practices 

that correspond to these regulations. 

Regulatory Evaluation, Regulatory 

Flexibility Determination, International 

Trade Impact Assessment, and 

Unfunded Mandates Assessment 

Changes to Federal regulations must 

undergo several economic analyses. 

First, Executive Order 12866 directs that 

each Federal agency shall propose or 

adopt a regulation only upon a reasoned 

determination that the benefits of the 

intended regulation justify its costs. 

Second, the Regulatory Flexibility Act 

of 1980 (Pub. L. 96–354) requires 

agencies to analyze the economic 

impact of regulatory changes on small 

entities. Third, the Trade Agreements 

Act (Pub. L. 96–39) prohibits agencies 

from setting standards that create 

unnecessary obstacles to the foreign 

commerce of the United States. In 

developing U.S. standards, the Trade 

Act requires agencies to consider 

international standards and, where 

appropriate, that they be the basis of 

U.S. standards. Fourth, the Unfunded 

Mandates Reform Act of 1995 (Pub. L. 

104–4) requires agencies to prepare a 

written assessment of the costs, benefits, 

and other effects of proposed or final 

rules that include a Federal mandate 

likely to result in the expenditure by 

State, local, or Tribal governments, in 

the aggregate, or by the private sector, of 

$100 million or more annually (adjusted 

for inflation with base year of 1995). 

This portion of the preamble contains 

the FAA’s analysis of the economic 

impacts of this rule. 

In conducting these analyses, FAA 

has determined that this final rule: (1) 

Has benefits that justify its costs, (2) is 

not an economically ‘‘significant 

regulatory action’’ as defined in section 

3(f) of Executive Order 12866, (3) is not 

‘‘significant’’ as defined in DOT’s 

Regulatory Policies and Procedures; (4) 

will not have a significant economic 

impact on a substantial number of small 

entities; (5) will not create unnecessary 

obstacles to the foreign commerce of the 

United States; and (6) will not impose 

an unfunded mandate on State, local, or 

Tribal governments, or on the private 

sector by exceeding the threshold 

identified above. These analyses are 

summarized as follows. 

Total Benefits and Costs of This Rule 

This rule allows certain sensor signals 

to be filtered only if either (1) the 

recorded data meet the requirements in 

the appropriate appendix, or (2) the 

certificate holder can show that the 

original sensor signal data can be 

reconstructed to meet those 

requirements. The final rule cost will be 

about $310,000, which has a present 

value of about $261,000 using a 7 

percent discount rate and a present 

value of about $288,000 using a 3 

percent discount rate. The benefits of 

this rule are that certificate holders will 

have an alternative means of 

compliance with the filtering 

regulations and that the NTSB will have 

more accurate DFDR data for its 

accident investigations. 

Aviation Industry Affected 

The rule applies to each aircraft 

operated under part 121, 125, or 135 

that is required to have a DFDR system. 

These aircraft are operated primarily by 

scheduled air carriers and nonscheduled airplane and rotorcraft 

operators. Aircraft operated under other 

parts of Title 14 are not affected. 

Assumptions 

• Discount rate—7%. Sensitivity 

analysis was performed at 3% and 7% 

discount rates. 

• Period of Analysis—2010–2011. 

• Burdened labor rate for engineers 

and maintenance foremen—$83.12 per 

hour.1

• Rule issued on January 1, 2010. 

• Costs are based on 2008 dollars. 

• Manufacturers complete DFDR 

system analysis during 2010. 

• Certificate holders report DFDR 

system information in each aircraft’s 

correlation documentation during 2011. 

Changes From the 2006 NPRM to the 

Final Rule 

The 2006 NPRM had proposed to 

prohibit filtering certain original flight 

data sensor signals, which may have 

required certificate holders to redesign 

their DFDR systems to remove filtering. 

The final rule allows certain original 

flight data sensor signals to be filtered 

if the recorded data meet the accuracy 

requirements of the applicable appendix 

or, if they do not meet these 

requirements, that the certificate holder 

can show that the original flight data 

sensor signals can be reconstructed. The 

reconstruction procedures and test 

results must be submitted to the FAA 

and be validated to ensure that the 

required accuracy is being met and the 

process is repeatable. 

Benefits of This Rule 

The Flight 587 accident demonstrated 

the existence of a filtered data recording 

problem. The lack of accurate and 

complete recorded flight data hampered 

and delayed the accident investigation. 

The lack of data also introduced an 

element of uncertainty into the 

determination of the accident’s cause. 

Since the 2006 NPRM, comments 

received from the industry and our 

increasing understanding of the 

developments in data recording 

capability have led the FAA to conclude 

that data filtering, in and of itself, may 

not necessarily generate misleading or 

incomplete information that would 

inherently compromise an accident 

investigation. As long as the recorded 

sensor signal data meet the accuracy 

specifications, whether the data are 

filtered is not relevant to the progress of 

a subsequent accident investigation. 

However, as previously described, there 

are eight parameters that are too critical 

to accident investigation to allow them 

to be filtered freely. These recorded data 

may, if filtered, be misleading or 

incomplete and prevent a timely and 

thorough accident investigation. This 

final rule eliminates that possibility by 

requiring that, for those eight 

parameters, the aircraft DFDR system 

either (1) record unfiltered data, (2) 

record filtered data that meet the 

required accuracy specifications, or (3) 

record filtered data that can be 

reconstructed to recover the original 

unfiltered sensor signal values. So long 

as the applicable appendix requirements 

are met, this rule allows the certificate 


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holder to select the lowest cost 

compliance alternative. 

The primary benefit from this rule 

remains better, quicker, and less 

expensive accident investigations. 

Although the public comments 

provided no quantitative information 

about the possible benefits of this 

improved information, the NTSB 

believes that these benefits exist and the 

FAA agrees. 

Costs of This Rule 

Calculation of the costs of this rule 

begins with the presumption that each 

affected aircraft’s DFDR system already 

records results that comply with the 

requirements in Appendix B or M of 

part 121, Appendix D or E of part 125, 

or Appendix F of part 135. These 

regulations were adopted in 1997, with 

compliance due no later than 2001. If an 

operator finds that it has aircraft that do 

not comply with the applicable 1997 

appendix requirements, the costs to 

bring those aircraft into compliance 

would be a cost of the 1997 rule, not 

this final rule. 

The initial action necessary to comply 

with this rule is an analysis of the 

aircraft DFDR system to determine 

whether data are being filtered. Most 

certificate holders do not have the 

technical capabilities to perform an 

engineering analysis of DFDR systems. 

However, aircraft manufacturers have 

the capability and the FAA anticipates 

that they will perform these analyses 

and provide the information to the 

certificate holders. The second action to 

comply with this rule will be for the 

certificate holder to create a report 

indicating the status of each airplane 

regarding filtering. That data must be 

maintained as part of the flight data 

recorder correlation data already 

required by the regulations. 

Industry sources indicated to the FAA 

that these engineering analyses will 

require minimal time because most of 

the work was completed during the 

aircraft certification and is already in 

the possession of the manufacturers. For 

example, GAMA estimated that one of 

its operators would need 10 hours to 

complete this analysis for one of its 

aircraft models. The FAA determined 

that the average amount of time a 

manufacturer needs to gather the 

certification information, review it, 

complete an analysis and produce a 

service bulletin (or equivalent) is 25 

hours for one aircraft model. Clearly, 

some of these analyses will take more 

than 25 hours while others (primarily 

those for more recently-certificated 

aircraft models) will simply require the 

manufacturer to review the results of 

these recent certification tests. Finally, 

for operators to comply with the 18- 

month requirement for reporting the 

DFDR system status to the FAA, the 

manufacturers will need to complete 

this process during 2010, which is the 

first year after issuing the final rule. 

The FAA determined that there are 40 

large transport category commercial 

airplane models affected by this rule. At 

a cost of $2,078 for each analysis (25 

hours at $83.12 per hour), the total cost 

will be $83,120, which has a present 

value of $72,600 using a 7 percent 

discount rate, and a present value of 

$78,349 using a 3 percent discount rate. 

There are 11 other jet airplane models 

certificated for 10 or more passengers 

that are used in part 135 non-scheduled 

operations. At a cost of $2,078 for an 

analysis, the total cost will be $22,858, 

which has a present value of $19,955 

using a 7 percent discount rate, and a 

present value of $21,546 using a 3 

percent discount rate. 

There are 16 turboprop airplane 

models certificated for 10 or more 

passengers that are used in part 135 

non-scheduled operations. At a cost of 

$2,078 for each analysis, the total cost 

will be $33,248, which has a present 

value of $29,040 using a 7 percent 

discount rate, and a present value of 

$31,339 using a 3 percent discount rate. 

Finally, there are six rotorcraft models 

certificated for 10 or more passengers 

that are used in part 135 non-scheduled 

operations. At a cost of $2,078 for each 

analysis, the total cost will be $12,468, 

which has a present value of $10,890 

using a 7 percent discount rate and a 

present value of $11,752 using a 3 

percent discount rate. 

Thus, as shown in Table 1, the total 

cost to manufacturers will be $151,694, 

which has a present value of $132,495 

using a 7 percent discount rate and a 

present value of $142,986 using a 3 

percent discount rate. 

TABLE 1—TOTAL COSTS AND PRESENT VALUE COSTS FOR THE MANUFACTURER ANALYSES OF AIRCRAFT BY TYPE OF

AIRCRAFT

[In 2008 dollars] 

Type of aircraft Total cost Present value 

(at 7 percent) 

Present value 

(at 3 percent) 

Airplanes Used in Parts 121 and 125 ............................................................................. $83,120 $72,600 $78,349 

Jets Used in Part 135 ...................................................................................................... 22,858 19,965 21,546 

Turboprops Used in Part 135 .......................................................................................... 33,248 29,040 31,339 

Rotorcraft Used in Part 135 ............................................................................................. 12,468 10,890 11,752 

Total .......................................................................................................................... 151,694 132,495 142,986 

One issue that arose was the cost to 

perform these analyses for DFDR 

systems that have been sufficiently 

modified to require a supplemental type 

certificate. The FAA determined that 

this issue is not significant because such 

modifications are infrequent and 

generally do not provide any 

operational advantage. 

However, each certificate holder has 

the ultimate responsibility to ensure 

that all of its aircraft DFDR systems are 

recording sensor signal data that meet 

the applicable range, resolution, and 

accuracy specifications. As discussed, 

although the manufacturer will provide 

its data to the certificate holder, each 

certificate holder must indicate, for each 

of its aircraft, the compliance status of 

that aircraft, including whether data 

from the manufacturer applies to 

individual aircraft. Thus, the certificate 

holder’s incremental compliance cost is 

the paperwork cost to record the 

compliance status of its aircraft. The 

FAA anticipates that this notification 

will be made during the first half of 

2011, the second year after the final rule 

is issued. 

The FAA determined that, on average, 

it will take a certificate holder’s 

maintenance foreman 15 minutes for a 

one-time total cost of $20.78 per aircraft 

to record in an aircraft’s correlation 

documentation whether any data are 

being filtered. 

There were 7,274 airplanes operated 

under parts 121 and 125 required to 


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2FAA Aerospace Forecast Fiscal Years 2009– 

2025, Tables 20, 21, and 26, pp. 79, 80, and 85. 

have a DFDR system in 2008.2 There 

were 43 jet airplanes, 269 turboprop 

airplanes and 37 rotorcraft operating in 

part 135 unscheduled service required 

to have a DFDR system in 2009. 

On that basis, part 121 and 125 

operators will incur recordation costs of 

$151,154, part 135 non-scheduled jet 

operators will incur recordation costs of 

$894, part 135 non-scheduled turboprop 

operators will incur recordation costs of 

$5,590, and part 135 non-scheduled 

helicopter operators will incur 

recordation costs of $769. 

Thus, as shown in Table 2, the total 

cost to operators will be $158,406, 

which has a present value of $129,306 

using a 7 percent discount rate, and a 

present value of $144,964 using a 

discount rate of 3 percent. 

TABLE 2—TOTAL COSTS AND PRESENT VALUE COSTS FOR OPERATORS TO REPORT COMPLIANCE TO THE FAA DURING

2011 

[In 2008 dollars] 

Type of certificate holder Total cost Present value 

(at 7 percent) 

Present value 

(at 3 percent) 

Parts 121 and 125 Operators .......................................................................................... $151,154 $123,386 $138,327 

Non-Scheduled Jet .......................................................................................................... 894 729 818 

Non-Scheduled Turboprop .............................................................................................. 5,590 4,563 5,115 

Rotorcraft ......................................................................................................................... 769 628 704 

Total .......................................................................................................................... 158,406 129,306 144,964 

There is a potential compliance cost 

if a manufacturer informs an operator 

that some of its aircraft DFDR systems 

are recording filtered flight data for any 

of the eight critical parameters. The 

final rule requires that if an operator is 

so informed, then the operator must 

evaluate each filtered parameter to 

ensure that the recorded data meet the 

requirements of the appropriate 

appendix. The cost of this evaluation is 

a cost of this final rule. Based on an 

FAA determination that such an 

evaluation will take four labor hours at 

a cost of $83.12 an hour to complete, the 

cost for an operator to complete an 

evaluation for each affected parameter 

on each affected aircraft will be $332.48. 

No manufacturer reported to the 

docket whether any of its aircraft DFDR 

systems were recording filtered data for 

any of these eight parameters. As a 

consequence, the FAA does not know 

whether there is any such filtered data 

recording, or the number of affected 

parameters or the number of affected 

aircraft DFDR systems. 

Therefore, the FAA can only estimate 

that if there are DFDR systems recording 

filtered data, it will cost an operator 

$332.48 to evaluate each affected 

parameter on each affected aircraft. 

Thus, the FAA calculated that, as 

shown in Table 3, the total cost to 

comply with this rule is $310,100, 

which has a present value of $261,801 

using a 7 percent discount rate, and a 

present value of $287,950 using a 

discount rate of 3 percent. 

TABLE 3—TOTAL COSTS AND PRESENT VALUE COSTS TO REPORT COMPLIANCE WITH THE FINAL RULE

[In 2008 dollars] 

Type of entity Total cost Present value 

(at 7 percent) 

Present value 

(at 3 percent) 

Manufacturer .................................................................................................................... $151,694 $132,495 $142,986 

Operator ........................................................................................................................... 158,406 129,306 144,964 

Total .......................................................................................................................... 310,100 261,801 287,950 

As previously discussed, this total 

cost does not include any potential 

operator costs to determine that any 

filtered data meets the requirements of 

the appropriate appendix because the 

FAA does not know whether or to what 

extent the DFDR systems are recording 

filtered data. 

If a DFDR system is recording data for 

parameters 12 through 17, 42, or 88 that 

do not meet the requirements of 

Appendix M because of filtering, the 

certificate holder has the choice of two 

methods of compliance. One method 

would be to remove the filtering. The 

other method would be for the 

certificate holder to demonstrate that 

the original sensor signal data (values) 

can be acceptably reconstructed using a 

valid, repeatable procedure. The cost of 

either action is a cost to comply with 

the existing standard and, therefore, is 

not a cost of this rule. 

In fact, this rule, by allowing an 

alternative to removing the filtering, 

may reduce the costs to bring out-ofcompliance aircraft into compliance 

with the appropriate appendix. We 

asked for cost information for these 

actions in the SNPRM, but received no 

data. 

Benefit Cost Analysis 

The FAA believes that the rule will 

provide accident investigators with the 

more accurate and less ambiguous data 

necessary to determine the causes of 

aircraft accidents in a more timely and 

less expensive way. It also provides 

operators with a less costly means than 

the 2006 NPRM to comply with the 

applicable requirements. As a result, the 

FAA has determined that the benefits 

from this rule are greater than the costs. 

Regulatory Flexibility Analysis 

The Regulatory Flexibility Act of 1980 

(Pub. L. 96–354) (RFA) establishes ‘‘as a 

principle of regulatory issuance that 


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Federal Register / Vol. 75, No. 33 / Friday, February 19, 2010 / Rules and Regulations 7355 

agencies shall endeavor, consistent with 

the objectives of the rule and of 

applicable statutes, to fit regulatory and 

informational requirements to the scale 

of the businesses, organizations, and 

governmental jurisdictions subject to 

regulation. To achieve this principle, 

agencies are required to solicit and 

consider flexible regulatory proposals 

and to explain the rationale for their 

actions to assure that such proposals are 

given serious consideration.’’ The RFA 

covers a wide-range of small entities, 

including small businesses, not-forprofit organizations, and small 

governmental jurisdictions. 

Agencies must perform a review to 

determine whether a rule will have a 

significant economic impact on a 

substantial number of small entities. If 

the agency determines that it will, the 

agency must prepare a regulatory 

flexibility analysis as described in the 

RFA. 

However, if an agency determines that 

a rule is not expected to have a 

significant economic impact on a 

substantial number of small entities, 

section 605(b) of the RFA provides that 

the head of the agency may so certify 

and a regulatory flexibility analysis is 

not required. The certification must 

include a statement providing the 

factual basis for this determination, and 

the reasoning should be clear. 

In the SNPRM, the FAA requested 

information specific to small entities, 

but received none. In the regulatory 

evaluation, the FAA calculated that the 

cost to create a record of the compliance 

status of each aircraft would be $20.78, 

which is a minimal cost to a small 

entity. Subsequent costs to bring a noncompliant aircraft into compliance may 

be attributable to the 1997 regulation. 

This final rule may reduce some of 

those costs by allowing the certificate 

holder to select a compliance alternative 

that was not previously available. 

Therefore, I certify that this rule will 

not have a significant economic impact 

on a substantial number of small 

entities. 

International Trade Analysis 

The Trade Agreements Act of 1979 

(Pub. L. 96–39), as amended by the 

Uruguay Round Agreements Act (Pub. 

L. 103–465), prohibits Federal agencies 

from establishing any standards or 

engaging in related activities that create 

unnecessary obstacles to the foreign 

commerce of the United States. 

Pursuant to these Acts, the 

establishment of standards is not 

considered unnecessary obstacles to the 

foreign commerce of the United States, 

so long as the standards have a 

legitimate domestic objective, such the 

protection of safety, and do not operate 

in a manner that excludes imports that 

meet this objective. The statute also 

requires consideration of international 

standards and, where appropriate, that 

they be the basis for U.S. standards. The 

FAA notes the purpose is to ensure the 

safety of the American public, and has 

assessed the effects of this rule to ensure 

it does not exclude imports that meet 

this objective. As a result, this final rule 

is not considered as creating an 

unnecessary obstacle to foreign 

commerce. 

Unfunded Mandates Act 

Title II of the Unfunded Mandates 

Reform Act of 1995 (Pub. L. 104–4) 

requires each Federal agency to prepare 

a written statement assessing the effects 

of any Federal mandate in a proposed or 

final agency rule that may result in an 

expenditure of $100 million or more 

(adjusted annually for inflation with the 

base year 1995) in any one year by State, 

local, and Tribal governments, in the 

aggregate, or by the private sector; such 

a mandate is deemed to be a ‘‘significant 

regulatory action.’’ The FAA currently 

uses an inflation-adjusted value of 

$136.1 million in lieu of $100 million. 

This final rule does not contain such 

a mandate; therefore, the requirements 

of Title II of the Act do not apply. 

Executive Order 13132, Federalism 

The FAA has analyzed this final rule 

under the principles and criteria of 

Executive Order 13132, Federalism. We 

determined that this action would not 

have a substantial direct effect on the 

States, or the relationship between the 

Federal Government and the States, or 

on the distribution of power and 

responsibilities among the various 

levels of government, and, therefore, 

does not have federalism implications. 

Environmental Analysis 

FAA Order 1050.1E identifies FAA 

actions that are categorically excluded 

from preparation of an environmental 

assessment or environmental impact 

statement under the National 

Environmental Policy Act in the 

absence of extraordinary circumstances. 

The FAA has determined this 

rulemaking qualifies for the categorical 

exclusion identified in Chapter 3, 

paragraph 312f and involves no 

extraordinary circumstances. 

Regulations That Significantly Affect 

Energy Supply, Distribution, or Use 

The FAA has analyzed this final rule 

under Executive Order 13211, Actions 

Concerning Regulations that 

Significantly Affect Energy Supply, 

Distribution, or Use (May 18, 2001). We 

have determined that it is not a 

‘‘significant energy action’’ under the 

executive order because it is not a 

‘‘significant regulatory action’’ under 

Executive Order 12866, and it is not 

likely to have a significant adverse effect 

on the supply, distribution, or use of 

energy. 

Regulations Affecting Intrastate 

Aviation in Alaska 

Section 1205 of the FAA 

Reauthorization Act of 1996 (110 Stat. 

3213) requires the FAA, when 

modifying its regulations in a manner 

affecting intrastate aviation in Alaska, to 

consider the extent to which Alaska is 

not served by transportation modes 

other than aviation, and to establish 

appropriate regulatory distinctions. In 

the NPRM, we requested comments on 

whether the proposed rule should apply 

differently to intrastate operations in 

Alaska. We did not receive any 

comments, and we have determined, 

based on the administrative record of 

this rulemaking, that there is no need to 

make any regulatory distinctions 

applicable to intrastate aviation in 

Alaska. 

Availability of Rulemaking Documents 

You can get an electronic copy of 

rulemaking documents using the 

Internet by— 

1. Searching the Federal eRulemaking 

Portal (http://www.regulations.gov); 

2. Visiting the FAA’s Regulations and 

Policies Web page at http:// 

www.faa.gov/regulations_policies/; or 

3. Accessing the Government Printing 

Office’s Web page at http:// 

www.gpoaccess.gov/fr/index.html. 

You can also get a copy by sending a 

request to the Federal Aviation 

Administration, Office of Rulemaking, 

ARM–1, 800 Independence Avenue 

SW., Washington, DC 20591, or by 

calling (202) 267–9680. Make sure to 

identify the docket number or 

amendment number of this rulemaking. 

You may search the electronic form of 

all comments received into any of our 

dockets by the name of the individual 

submitting the comment (or signing the 

comment, if submitted on behalf of an 

association, business, labor union, etc.). 

You may review DOT’s complete 

Privacy Act statement in the Federal 

Register published on April 11, 2000 

(Volume 65, Number 70; Pages 19477– 

78) or you may visit http:// 

DocketsInfo.dot.gov. 

Small Business Regulatory Enforcement 

Fairness Act 

The Small Business Regulatory 

Enforcement Fairness Act (SBREFA) of 

1996 requires FAA to comply with 


srobinson on DSKHWCL6B1PROD with RULES
7356 Federal Register / Vol. 75, No. 33 / Friday, February 19, 2010 / Rules and Regulations 

small entity requests for information or 

advice about compliance with statutes 

and regulations within its jurisdiction. If 

you are a small entity and you have a 

question regarding this document, you 

may contact your local FAA official, or 

the person listed under the FOR FURTHER

INFORMATION CONTACT heading at the 

beginning of the preamble. You can find 

out more about SBREFA on the Internet 

at http://www.faa.gov/ 

regulations_policies/rulemaking/ 

sbre_act/. 

List of Subjects in 14 CFR Parts 121, 

125, and 135 

Air carriers, Aircraft, Aviation safety, 

Safety, Transportation. 

The Amendment 

■ In consideration of the foregoing, the 

Federal Aviation Administration 

amends Chapter I of Title 14, Code of 

Federal Regulations, as follows: 

PART 121—OPERATING 

REQUIREMENTS: DOMESTIC, FLAG, 

AND SUPPLEMENTAL OPERATIONS 

■ 1. The authority citation for part 121 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 1153, 40101, 

40102, 40103, 40113, 41721, 44105, 44106, 

44111, 44701–44717, 44722, 44901, 44903, 

44904, 44906, 44912, 44914, 44936, 44938, 

46103, 46105. 

■ 2. Revise § 121.344a(e) to read as 

follows: 

§ 121.344a Digital flight data recorders for 

10–19 seat airplanes. 

* * * * * 

(e) All airplanes subject to this section 

are also subject to the requirements and 

exceptions stated in § 121.344(g) 

through (k) and § 121.346. 

* * * * * 

■ 3. Add a new § 121.346 to read as 

follows: 

§ 121.346 Flight data recorders: filtered 

data. 

(a) A flight data signal is filtered when 

an original sensor signal has been 

changed in any way, other than changes 

necessary to: 

(1) Accomplish analog to digital 

conversion of the signal; 

(2) Format a digital signal to be DFDR 

compatible; or 

(3) Eliminate a high frequency 

component of a signal that is outside the 

operational bandwidth of the sensor. 

(b) An original sensor signal for any 

flight recorder parameter required to be 

recorded under § 121.344 may be 

filtered only if the recorded signal value 

continues to meet the requirements of 

Appendix B or M of this part, as 

applicable. 

(c) For a parameter described in 

§ 121.344(a) (12) through (17), (42), or 

(88), or the corresponding parameter in 

Appendix B of this part, if the recorded 

signal value is filtered and does not 

meet the requirements of Appendix B or 

M of this part, as applicable, the 

certificate holder must: 

(1) Remove the filtering and ensure 

that the recorded signal value meets the 

requirements of Appendix B or M of this 

part, as applicable; or 

(2) Demonstrate by test and analysis 

that the original sensor signal value can 

be reconstructed from the recorded data. 

This demonstration requires that: 

(i) The FAA determine that the 

procedure and the test results submitted 

by the certificate holder as its 

compliance with paragraph (c)(2) of this 

section are repeatable; and 

(ii) The certificate holder maintains 

documentation of the procedure 

required to reconstruct the original 

sensor signal value. This documentation 

is also subject to the requirements of 

§ 121.344(i). 

(d) Compliance. Compliance is 

required as follows: 

(1) No later than October 20, 2011, 

each operator must determine, for each 

airplane on its operations specifications, 

whether the airplane’s DFDR system is 

filtering any of the parameters listed in 

paragraph (c) of this section. The 

operator must create a record of this 

determination for each airplane it 

operates, and maintain it as part of the 

correlation documentation required by 

§ 121.344(j)(3) of this part. 

(2) For airplanes that are not filtering 

any listed parameter, no further action 

is required unless the airplane’s DFDR 

system is modified in a manner that 

would cause it to meet the definition of 

filtering on any listed parameter. 

(3) For airplanes found to be filtering 

a parameter listed in paragraph (c) of 

this section, the operator must either: 

(i) No later than April 21, 2014, 

remove the filtering; or 

(ii) No later than April 22, 2013, 

submit the necessary procedure and test 

results required by paragraph (c)(2) of 

this section. 

(4) After April 21, 2014, no aircraft 

flight data recording system may filter 

any parameter listed in paragraph (c) of 

this section that does not meet the 

requirements of Appendix B or M of this 

part, unless the certificate holder 

possesses test and analysis procedures 

and the test results that have been 

approved by the FAA. All records of 

tests, analysis and procedures used to 

comply with this section must be 

maintained as part of the correlation 

documentation required by 

§ 121.344(j)(3) of this part. 

■ 4. Amend Appendix M to part 121 by 

revising the introductory text to read as 

follows: 

Appendix M to Part 121—Airplane 

Flight Recorder Specifications 

The recorded values must meet the 

designated range, resolution and accuracy 

requirements during static and dynamic 

conditions. Dynamic condition means the 

parameter is experiencing change at the 

maximum rate attainable, including the 

maximum rate of reversal. All data recorded 

must be correlated in time to within one 

second. 

* * * * * 

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 

■ 5. The authority citation for part 125 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701– 

44702, 44705, 44710–44711, 44713, 44716– 

44717, 44722. 

■ 6. Add a new § 125.228 in Subpart F 

to read as follows: 

§ 125.228 Flight data recorders: filtered 

data. 

(a) A flight data signal is filtered when 

an original sensor signal has been 

changed in any way, other than changes 

necessary to: 

(1) Accomplish analog to digital 

conversion of the signal; 

(2) Format a digital signal to be DFDR 

compatible; or 

(3) Eliminate a high frequency 

component of a signal that is outside the 

operational bandwidth of the sensor. 

(b) An original sensor signal for any 

flight recorder parameter required to be 

recorded under § 125.226 may be 

filtered only if the recorded signal value 

continues to meet the requirements of 

Appendix D or E of this part, as 

applicable. 

(c) For a parameter described in 

§ 125.226(a) (12) through (17), (42), or 

(88), or the corresponding parameter in 

Appendix D of this part, if the recorded 

signal value is filtered and does not 

meet the requirements of Appendix D or 

E of this part, as applicable, the 

certificate holder must: 

(1) Remove the filtering and ensure 

that the recorded signal value meets the 

requirements of Appendix D or E of this 

part, as applicable; or 

(2) Demonstrate by test and analysis 

that the original sensor signal value can 

be reconstructed from the recorded data. 

This demonstration requires that: 


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Federal Register / Vol. 75, No. 33 / Friday, February 19, 2010 / Rules and Regulations 7357 

(i) The FAA determine that the 

procedure and the test results submitted 

by the certificate holder as its 

compliance with paragraph (c)(2) of this 

section are repeatable; and 

(ii) The certificate holder maintains 

documentation of the procedure 

required to reconstruct the original 

sensor signal value. This documentation 

is also subject to the requirements of 

§ 125.226(i). 

(d) Compliance. Compliance is 

required as follows: 

(1) No later than October 20, 2011, 

each operator must determine, for each 

airplane it operates, whether the 

airplane’s DFDR system is filtering any 

of the parameters listed in paragraph (c) 

of this section. The operator must create 

a record of this determination for each 

airplane it operates, and maintain it as 

part of the correlation documentation 

required by § 125.226(j)(3) of this part. 

(2) For airplanes that are not filtering 

any listed parameter, no further action 

is required unless the airplane’s DFDR 

system is modified in a manner that 

would cause it to meet the definition of 

filtering on any listed parameter. 

(3) For airplanes found to be filtering 

a parameter listed in paragraph (c) of 

this section, the operator must either: 

(i) No later than April 21, 2014, 

remove the filtering; or 

(ii) No later than April 22, 2013, 

submit the necessary procedure and test 

results required by paragraph (c)(2) of 

this section. 

(4) After April 21, 2014, no aircraft 

flight data recording system may filter 

any parameter listed in paragraph (c) of 

this section that does not meet the 

requirements of Appendix D or E of this 

part, unless the certificate holder 

possesses test and analysis procedures 

and the test results that have been 

approved by the FAA. All records of 

tests, analysis and procedures used to 

comply with this section must be 

maintained as part of the correlation 

documentation required by 

§ 125.226(j)(3) of this part. 

■ 7. Amend Appendix E to part 125 by 

revising the introductory to read as 

follows: 

Appendix E to Part 125—Airplane 

Flight Recorder Specifications 

The recorded values must meet the 

designated range, resolution and accuracy 

requirements during static and dynamic 

conditions. Dynamic condition means the 

parameter is experiencing change at the 

maximum rate attainable, including the 

maximum rate of reversal. All data recorded 

must be correlated in time to within one 

second. 

* * * * * 

PART 135—OPERATING 

REQUIREMENTS: COMMUTER AND 

ON DEMAND OPERATIONS AND 

RULES GOVERNING PERSONS ON 

BOARD SUCH AIRCRAFT 

■ 8. The authority citation for part 135 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 41706, 44113, 

44701–44702, 44705, 44709, 44711–44713, 

44715–44717, 44722. 

■ 9. Add a new § 135.156 to read as 

follows: 

§ 135.156 Flight data recorders: filtered 

data. 

(a) A flight data signal is filtered when 

an original sensor signal has been 

changed in any way, other than changes 

necessary to: 

(1) Accomplish analog to digital 

conversion of the signal; 

(2) Format a digital signal to be DFDR 

compatible; or 

(3) Eliminate a high frequency 

component of a signal that is outside the 

operational bandwidth of the sensor. 

(b) An original sensor signal for any 

flight recorder parameter required to be 

recorded under § 135.152 may be 

filtered only if the recorded signal value 

continues to meet the requirements of 

Appendix D or F of this part, as 

applicable. 

(c) For a parameter described in 

§ 135.152(h)(12) through (17), (42), or 

(88), or the corresponding parameter in 

Appendix D of this part, if the recorded 

signal value is filtered and does not 

meet the requirements of Appendix D or 

F of this part, as applicable, the 

certificate holder must: 

(1) Remove the filtering and ensure 

that the recorded signal value meets the 

requirements of Appendix D or F of this 

part, as applicable; or 

(2) Demonstrate by test and analysis 

that the original sensor signal value can 

be reconstructed from the recorded data. 

This demonstration requires that: 

(i) The FAA determine that the 

procedure and test results submitted by 

the certificate holder as its compliance 

with paragraph (c)(2) of this section are 

repeatable; and 

(ii) The certificate holder maintains 

documentation of the procedure 

required to reconstruct the original 

sensor signal value. This documentation 

is also subject to the requirements of 

§ 135.152(e). 

(d) Compliance. Compliance is 

required as follows: 

(1) No later than October 20, 2011, 

each operator must determine, for each 

aircraft on its operations specifications, 

whether the aircraft’s DFDR system is 

filtering any of the parameters listed in 

paragraph (c) of this section. The 

operator must create a record of this 

determination for each aircraft it 

operates, and maintain it as part of the 

correlation documentation required by 

§ 135.152 (f)(1)(iii) or (f)(2)(iii) of this 

part as applicable. 

(2) For aircraft that are not filtering 

any listed parameter, no further action 

is required unless the aircraft’s DFDR 

system is modified in a manner that 

would cause it to meet the definition of 

filtering on any listed parameter. 

(3) For aircraft found to be filtering a 

parameter listed in paragraph (c) of this 

section the operator must either: 

(i) No later than April 21, 2014, 

remove the filtering; or 

(ii) No later than April 22, 2013, 

submit the necessary procedure and test 

results required by paragraph (c)(2) of 

this section. 

(4) After April 21, 2014, no aircraft 

flight data recording system may filter 

any parameter listed in paragraph (c) of 

this section that does not meet the 

requirements of Appendix D or F of this 

part, unless the certificate holder 

possesses test and analysis procedures 

and the test results that have been 

approved by the FAA. All records of 

tests, analysis and procedures used to 

comply with this section must be 

maintained as part of the correlation 

documentation required by § 135.152 

(f)(1)(iii) or (f)(2)(iii) of this part as 

applicable. 

■ 10. Amend Appendix F to part 135 by 

revising the introductory text to read as 

follows: 

Appendix F to Part 135—Airplane 

Flight Recorder Specifications 

The recorded values must meet the 

designated range, resolution and accuracy 

requirements during static and dynamic 

conditions. Dynamic condition means the 

parameter is experiencing change at the 

maximum rate attainable, including the 

maximum rate of reversal. All data recorded 

must be correlated in time to within one 

second. 

* * * * * 

Issued in Washington, DC, on February 5, 

2010. 

J. Randolph Babbitt, 

Administrator. 

[FR Doc. 2010–3321 Filed 2–18–10; 8:45 am] 

BILLING CODE 4910–13–P 


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