[Federal Register Volume 67, Number 163 (Thursday, August 22, 2002)]
[Proposed Rules]
[Pages 54379-54380]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-21472]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. 26015; Notice No. 89-25]
RIN 2120-AD34


Airplane Engine Cowling Retention

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) (54 FR 38610, September 19, 1989) that would 
provide improved engine cowling retention for transport category 
airplanes by adding specific design requirements for cowling retention 
systems. The proposed rule would have promoted design and construction 
of cowling retention systems to withstand vibration, inertial loads, 
over-pressure, normal air loads, and thermal conditions of an engine 
compartment fire after failure or improper fastening of latching 
devices. We are withdrawing the proposed rule because the proposal has 
been surpassed by technological advances. The issues will be addressed 
by future regulatory action based on recommendations from the Aviation 
Rulemaking Advisory Committee, and will be harmonized with similar 
regulations in Europe and Transport Canada.

FOR FURTHER INFORMATION CONTACT: Michael McRae, Propulsion and 
Mechanical Systems Branch, Federal Aviation Administration, telephone 
425-227-2113, e-mail [email protected].

SUPPLEMENTARY INFORMATION

Background

    On September 19, 1989, the FAA published Notice of Proposed 
Rulemaking No. 89-25 (54 FR 38610) to propose an amendment to 14 CFR 
part 25, and invited public comment on the issue of engine cowling 
retention. Section 25.1193, Cowling and nacelle skin, addresses the 
design of engine cowlings, but does not address the single failure of a 
latch or hinge, or an improperly fastened latch. Several in-

[[Page 54380]]

flight incidents of engine cowling separation resulted in damage to 
airplanes and property on the ground, and highlighted the need to re-
evaluate the design and maintenance requirements applicable to engine 
cowlings. Notice No. 89-25 proposes to specify standards for failsafe 
criteria in the design of engine cowling retention systems, which would 
enable the systems to withstand the loss of a single latch and easily 
detect unlocked or improperly closed latches. The comment period for 
Notice No. 89-25 closed March 19, 1990.

Discussion of Comments

    Fifteen commenters responded to the NPRM. In general, most 
commenters are in favor of the proposed requirement for direct visual 
inspection of cowling retention systems, and are not in favor of the 
proposed cockpit visual warning system. A few commenters suggest 
additional enhancements to the proposal.
    Four commenters favor direct visual inspection of the cowling but 
oppose the cockpit visual warning system. One of these commenters 
states that the direct visual inspection makes redundant the proposed 
addition of a cockpit visual warning system. Another opposes the 
cockpit visual warning system stating that the system would not be 
justified economically or functionally. Others state that the cockpit 
visual warning system would be impractical, introduce the potential for 
false signal indications, add complexity, and increase potential for 
failures detrimental to safety.
    One commenter states that the real problem is inadequate preflight 
inspections. Another commenter notes concern about the clarity of 
terms, and the low probability of a double failure condition of an 
engine fire and an unlatched latch. An additional commenter considers 
the fundamental problem to be the lack of preload and resulting wear, 
plus any accidental damage done while opening or closing the latch. In 
response to commenters' interest in direct visual inspections, the FAA 
continues to require pilots to determine that an aircraft is in a 
condition safe for flight and encourage an on-going focus on 
appropriate preflight inspections to uphold safety standards.
    Commenters also express concern about harmonization of any engine 
cowling requirements. The withdrawal of Notice No. 89-25 will allow the 
FAA to consider harmonization concerns and address the issues more 
completely in future regulatory actions in consideration of 
recommendations developed within ARAC.

ICAO and Harmonization

    The International Civil Aviation Organization (ICAO) established 
the International Standards and Recommended Practices to promote 
international cooperation towards the highest possible degree of 
uniformity in regulations and standards. The FAA and the Joint Aviation 
Authorities (JAA) of Europe came together to standardize their 
respective codes of regulation and identified a number of significant 
regulatory differences. Both consider harmonization a high priority. 
The FAA tasked ARAC with the harmonization effort. In 1999, the FAA and 
JAA agreed on a Fast Track Harmonization Program to expedite the 
standardization process. ICAO Resolution A29-3, Global Rule 
Harmonization, urges States to take positive action to promote global 
harmonization of national rules for application of ICAO standards. The 
FAA actively supports ICAO initiatives and programs to achieve a safe 
and efficient aviation system worldwide.

Reason for Withdrawal

    The FAA is involved in eliminating unnecessary differences and 
harmonizing where practical similar requirements with the JAA and 
Transport Canada. The FAA finds that including the issues of Notice No. 
89-25 within harmonization efforts assigned to ARAC will contribute to 
a more complete analysis of the issues and will better serve the public 
interest. We will propose future changes to the Code of Federal 
Regulations to achieve harmonization through an NPRM with an 
opportunity for public comment. Therefore, the FAA withdraws Notice No. 
89-25, (54 FR 38610) published September 19, 1989.

    Issued in Washington, DC, on August 16, 2002.
Ronald T. Wojnar,
Deputy Director, Aircraft Certification Service (AIR-1).
[FR Doc. 02-21472 Filed 8-21-02; 8:45 am]
BILLING CODE 4910-13-P