[Federal Register Volume 64, Number 207 (Wednesday, October 27, 1999)]
[Proposed Rules]
[Pages 57794-57796]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-28076]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-232-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 777 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 777 series 
airplanes. This proposal would require replacement of the clevis ends 
on the tie rods for the center stowage bin supports with improved 
clevis ends. This proposal is prompted by a report that, under ultimate 
load conditions, the aluminum clevis ends on the tie rods for the 
center stowage bin supports can break. The actions specified by the 
proposed AD are intended to prevent broken tie rods, which could result 
in the center stowage bins dropping onto the passenger seats below, 
causing possible injury to the occupants.

DATES: Comments must be received by December 13, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-232-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Julie Alger, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue S.W., Renton, 
Washington 98055-4056; telephone (425) 227-2779; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications shall identify the Rules Docket number 
and be submitted in triplicate to the address specified above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice

[[Page 57795]]

must submit a self-addressed, stamped postcard on which the following 
statement is made: ``Comments to Docket Number 99-NM-232-AD.'' The 
postcard will be date stamped and returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 99-NM-232-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report from Boeing indicating that, under 
ultimate load conditions on certain Boeing Model 777 series airplanes, 
the aluminum clevis ends on the tie rods that attach the center stowage 
bin support structure to the airplane structure can break. Such 
breakage has been attributed to the material of which the clevis ends 
are made (aluminum). This condition, if not corrected, could result in 
misalignment of the center stowage bins. Multiple broken tie rods could 
allow the center stowage bins to drop onto the passenger seats below, 
causing possible injury to the occupants.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 777-25-
0120, dated February 11, 1999, which describes procedures for 
replacement of the aluminum clevis ends on affected tie rods (81 
locations on 777-200 airplanes, 115 locations on 777-300 airplanes) 
with new steel clevis ends. The steel clevis ends are stronger than the 
aluminum clevis ends and will not break under ultimate load conditions. 
Accomplishment of the actions specified in the service bulletin is 
intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the service bulletin described previously.

Cost Impact

    There are approximately 184 airplanes (168 Model 777-200 and 16 
Model 777-300) of the affected design in the worldwide fleet. The FAA 
estimates that 41 airplanes of U.S. registry, all Model 777-200 
airplanes, would be affected by this proposed AD, and that it would 
take approximately 12 work hours per airplane to accomplish the 
proposed replacement, at an average labor rate of $60 per work hour. 
Required parts would cost approximately $15,938 per airplane. Based on 
these figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $682,978, or $16,658 per airplane.
    Currently, there are no Model 777-300 airplanes on the U.S. 
Register that would be affected by this AD. However, should an 
unmodified airplane be imported and placed on the U.S. Register in the 
future, it would take approximately 17 work hours per airplane to 
accomplish the actions proposed by this AD, at an average labor rate of 
$60 per work hour. Required parts would cost approximately $18,457 per 
airplane. Based on these figures, the cost impact of the proposed AD on 
these airplanes is estimated to be $19,477 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the proposed requirements 
of this AD action, and that no operator would accomplish those actions 
in the future if this AD were not adopted.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

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


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Boeing: Docket 99-NM-232-AD.

    Applicability: Model 777 series airplanes, line numbers 2 
through 103 inclusive, 105 through 119 inclusive, and 121 through 
187 inclusive; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (b) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent broken tie rods, which could result in the center 
stowage bins dropping onto the passenger seats below, causing 
possible injury to the occupants, accomplish the following:
    (a) Within 4 years after the effective date of this AD, replace 
the aluminum clevis ends on the tie rods for the center stowage bin 
supports with new steel clevis ends, in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 777-25-0120, 
dated February 11, 1999.

Alternative Methods of Compliance

    (b) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Seattle ACO.
    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

[[Page 57796]]

Special Flight Permits

    (c) Special flight permits may be issued in accordance with 
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 
21.197 and 21.199) to operate the airplane to a location where the 
requirements of this AD can be accomplished.

    Issued in Renton, Washington, on October 21, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-28076 Filed 10-26-99; 8:45 am]
BILLING CODE 4910-13-U