[Federal Register Volume 67, Number 85 (Thursday, May 2, 2002)]
[Proposed Rules]
[Pages 22019-22020]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-10946]


 ========================================================================
 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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  Federal Register / Vol. 67, No. 85 / Thursday, May 2, 2002 / Proposed 
Rules  

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

[14 CFR Part 33]

[Docket No. 24922; Notice No. 92-14]
RIN 2120-AB76


Airworthiness Standards: Aircraft Engines; Fuel and Induction 
Systems

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of Proposed Rulemaking (NPRM); withdrawal.

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SUMMARY: The FAA is withdrawing a previously published Notice of 
Proposed Rulemaking (NPRM) that proposed to require fail-safe design 
features in the fuel control systems used on reciprocating aircraft 
engines. The proposal would have required the fuel-air mixture control 
device and the throttle control device to move automatically to an 
acceptable position for continued safe operation if the linkage to 
these devices becomes disconnected. Based upon comments and after 
further analysis of the issue, we are withdrawing Notice No. 92-14 
because existing regulations adequately cover the issues contained in 
the NPRM, and Advisory Circular No. 20-143, Installation, Inspection, 
and Maintenance of Controls for General Aviation Reciprocating Aircraft 
Engines, issued on June 6, 2000, provides additional guidance on 
maintenance procedures.

FOR FURTHER INFORMATION CONTACT: Bonnie Fritts, ARM-28, Office of 
Rulemaking, Federal Aviation Administration, 800 Independence Avenue, 
SW, Washington, DC 20591; telephone (202) 267-7037; e-mail 
[email protected].

SUPPLEMENTARY INFORMATION

Background

    The FAA published an Advance Notice of Proposed Rulemaking (ANPRM) 
(51 FR 7224, Notice No. 86-2) on February 28, 1986, as a result of 
analysis of accidents attributed to mixture control failure. Accidents 
involving mixture and throttle control failures had resulted in serious 
injuries and a fatality. The National Transportation Safety Board 
(NTSB) analyzed 54 aircraft accidents and concluded that in most cases, 
failure of the mixture control linkage mechanism resulted in the 
mixture control moving to the idle cut-off position. Concerns of 
commenters to the ANPRM included inadequate maintenance, inclusion of a 
similar proposal on the throttle linkage, and that the full-rich 
mixture may not be the needed mixture position after linkage 
disconnect. The NTSB had also recommended a similar requirement for the 
throttle linkage.
    As a result of the information gathered from the ANPRM responses, 
the FAA published a Notice of Proposed Rulemaking (NPRM) (57 FR 47934, 
Notice No. 92-14) on October 20, 1992. Notice No. 86-2 had addressed 
mixture control failures. Notice No. 92-14 addressed both mixture and 
throttle control failures. The NPRM would have also removed the 
requirement that full-rich is the only acceptable mixture position 
following mixture control failure. The comment period of the NPRM 
closed February 17, 1993.
    After issuance of the NPRM, further investigations revealed the 
accidents were not a result of design problems, but were a result of 
inconsistent maintenance procedures involving throttle and mixture 
control cables. The FAA has determined that existing regulations 
adequately address the concerns of Notice No. 92-14, but to provide 
additional means of compliance, we have also issued an advisory 
circular to address maintenance procedures. We issued Advisory Circular 
No. 20-143, Installation, Inspection, and Maintenance of Controls for 
General Aviation Reciprocating Aircraft Engines, on June 6, 2000.

Discussion of Comments

    Twelve commenters responded to the NPRM. Concerns of commenters 
included maintenance techniques, editorial corrections to the NPRM, 
harmonization with Joint Aviation Authorities, and application of the 
proposed rulemaking to multi-engine aircraft.
    The National Transportation Safety Board concurred with the need to 
define and require fail-safe provisions at the engine certification 
level.
    The Air Line Pilots Association expressed support for the proposed 
rulemaking without further comment.
    The Joint Aviation Authorities (JAA) expressed concern that the 
proposed rulemaking creates new differences between the Joint Aviation 
Regulations and the Code of Federal Regulations. They also stated their 
position that an engine requirement is not the appropriate solution to 
the problem, as well as pointed out some editorial errors in the NPRM. 
They concluded that the FAA should cancel the NPRM or harmonize the 
issues with the JAA.
    Three aviation industry associations responded, two of which 
expressed concern that the proposal should not be mandatory for multi-
engine aircraft. One association suggested a review of maintenance 
techniques and withdrawal of the proposal, stating that the proposal 
increases opportunity for disaster.
    Two aviation industry manufacturers also cited maintenance 
procedures as a focus for further scrutiny. Of five individuals 
responding, one concerned about maintenance stated that ``given good 
maintenance, this problem should not exist.'' Another individual wanted 
the proposal to be made effective for new production engines after a 
specified date. Another supported the proposal but emphasized the need 
to keep requirements simple. Others suggested editorial changes to the 
proposed rule language and requested a detailed study of the problem.
    The greater number of commenters were concerned about effective 
maintenance procedures, which prompted further analysis of those 
procedures. Analysis revealed the issues contained in the NPRM to be 
largely a product of inconsistent maintenance practices involving 
throttle and mixture control cables. Based on the comments and further 
analysis of the issues, we provided additional guidance on maintenance 
procedures to complement existing regulations.

Reason for Withdrawal

    Existing regulations adequately cover the concerns of Notice No. 
92-14, but to provide additional means of compliance with the 
regulations, we have issued an advisory circular on maintenance

[[Page 22020]]

issues. Analysis revealed the issues addressed in the NPRM were largely 
a product of inconsistent maintenance practices. The FAA determined 
that issuance of an advisory circular was the proper method of dealing 
with the maintenance issues, and that a rule was not necessary. 
Advisory Circular No. 20-143, Installation, Inspection, and Maintenance 
of Controls for General Aviation Reciprocating Aircraft Engines, issued 
on June 6, 2000, addresses the issues contained in the NPRM. Therefore, 
we withdraw Notice No. 92-14, published October 20, 1992 at 57 FR 
47934.

    Issued in Washington, DC, on April 26, 2002.
John Hickey,
Director, Aircraft Certification Service, (AIR-1).
[FR Doc. 02-10946 Filed 5-1-02; 8:45 am]
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