[Federal Register Volume 68, Number 105 (Monday, June 2, 2003)]
[Proposed Rules]
[Page 32693]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-13647]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-30-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Proposed rule; withdrawal.

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SUMMARY: This action withdraws a notice of proposed rulemaking (NPRM) 
that proposed a new airworthiness directive (AD), applicable to all 
Boeing Model 777 series airplanes. That action would have required 
repetitive inspections for cracking of the floor beam structure located 
at body station 246; and repair, if necessary. Since the issuance of 
the NPRM, the Federal Aviation Administration (FAA) has received new 
data that indicate that the unsafe condition does not exist on the 
airplanes identified in the proposed rule. Accordingly, the proposed 
rule is withdrawn.

FOR FURTHER INFORMATION CONTACT: Gary Oltman, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
917-6443; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to add a new airworthiness 
directive (AD), applicable to all Boeing Model 777 series airplanes, 
was published in the Federal Register as a Notice of Proposed 
Rulemaking (NPRM) on June 19, 2002 (67 FR 41640). The NPRM would have 
required repetitive inspections for cracking of the floor beam 
structure located at body station 246; and repair, if necessary. That 
action was prompted by numerous reports of fatigue cracking of the 
floor beam structure located at body station (BS) 246 on several Boeing 
Model 777 series airplanes. The proposed actions were intended to find 
and fix such cracking, which could extend and sever the floor beam, 
resulting in rapid depressurization of the airplane and consequent 
collapse of the floor structure.

Actions That Occurred Since the NPRM Was Issued

    Since the issuance of that NPRM, the FAA has received new 
information as a comment from the airplane manufacturer (Boeing). The 
manufacturer indicated that even though the BS 246 floor beam cracking 
is not desirable, it did not result in an unsafe condition. As a 
result, we met with the manufacturer on December 5, 2002, and the 
manufacturer presented additional supporting data and analysis results.
    We have reviewed the data and concur with the manufacturer's 
conclusion that operators continue to find cracks, and that the type 
and extent of the floor beam cracking remains unchanged since the 
original findings. The analysis also showed that the cracked beam is 
prevented from deflecting to the point of affecting critical flight 
control.
    Based on these facts, we agree with the manufacturer's assessment 
that the cracking will not result in an unsafe condition, and the 
critical structural elements in the floor beam will continue to retain 
the required structural integrity throughout the life of the airplane.

FAA's Conclusions

    Upon further consideration, the FAA has determined that the unsafe 
condition does not exist on the airplanes identified in the NPRM. 
Accordingly, the proposed rule is hereby withdrawn.
    Withdrawal of this NPRM constitutes only such action, and does not 
preclude the agency from issuing another action in the future, nor does 
it commit the agency to any course of action in the future.

Regulatory Impact

    Since this action only withdraws a notice of proposed rulemaking, 
it is neither a proposed nor a final rule and therefore is not covered 
under Executive Order 12866, the Regulatory Flexibility Act, or DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979).

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Withdrawal

    Accordingly, the notice of proposed rulemaking, Docket 2001-NM-30-
AD, published in the Federal Register on June 19, 2002 (67 FR 41640), 
is withdrawn.

    Issued in Renton, Washington, on May 27, 2003.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-13647 Filed 5-30-03; 8:45 am]
BILLING CODE 4910-13-P