[Federal Register Volume 63, Number 91 (Tuesday, May 12, 1998)]
[Proposed Rules]
[Pages 26104-26106]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-12517]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-37-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757-200 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 757-200 
series airplanes. This proposal would require modifications to the 
attachment installation of the forward lavatory. This proposal is 
prompted by a stress analysis report indicating that the forward 
lavatory could break free from the upper and/or lower attachments 
during an emergency landing. The actions specified by the proposed AD 
are intended to prevent failure of the attachment installation of the 
forward lavatory during an emergency landing, which could result in 
injury to the crew and passengers.

DATES: Comments must be received by June 26, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-37-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: Keith Ladderud, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2780; 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 must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-37-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,

[[Page 26105]]

ANM-114, Attention: Rules Docket No. 98-NM-37-AD, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056.

Discussion

    While reviewing a stress analysis for the attachment installation 
of the forward lavatory on the Boeing Model 757-200 series airplane to 
add airline-requested variations, Boeing discovered a discrepancy with 
the analysis. The stress analysis, when corrected, indicated that the 
current design was not strong enough to withstand a 9g forward 
emergency landing. As a result, the upper attachment installation of 
the forward lavatory of passenger airplanes and the lower attachment 
installation of the forward lavatory of freighter airplanes do not meet 
the certification requirements for the ultimate load specifications of 
the forward lavatory. Furthermore, the stress analysis report indicated 
that the forward lavatory could break free at the upper and/or lower 
attachments during an emergency landing. Failure of the attachment 
installation of the forward lavatory during an emergency landing could 
result in injury to the crew and passengers.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 757-25-
0181, dated June 26, 1997, which describes procedures for installation 
of a doubler to the upper attachment installation of the forward 
lavatory on passenger airplanes. The FAA also has reviewed and approved 
Boeing Alert Service Bulletin 757-25A0187, dated September 18, 1997, 
which describes procedures for installation of floor panel inserts, a 
retention fitting assembly, and a doubler assembly to the lower 
attachment installation of the forward lavatory on freighter airplanes. 
Accomplishment of the modifications specified in the service bulletins 
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 modifications specified 
in the service bulletins described previously.

Cost Impact

    There are approximately 333 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 225 airplanes of U.S. registry 
would be affected by this proposed AD: 164 passenger airplanes and 61 
freighter airplanes.
    It would take approximately 10 work hours per passenger airplane to 
accomplish the proposed modification, at an average labor rate of $60 
per work hour. Required parts would cost approximately $100 per 
airplane. Based on these figures, the cost impact of this proposed 
modification on U.S. operators is estimated to be $114,800, or $700 per 
passenger airplane.
    It would take approximately 42 work hours per freighter airplane to 
accomplish the proposed modification, at an average labor rate of $60 
per work hour. Required parts would be provided by the airplane 
manufacturer at no cost to the operators. Based on these figures, the 
cost impact of this proposed modification on U.S. operators is 
estimated to be $153,720, or $2,520 per freighter 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 98-NM-37-AD.

    Applicability: Model 757-200 series airplanes; as listed in 
Boeing Service Bulletin 757-25-0181, dated June 26, 1997, and Boeing 
Alert Service Bulletin 757-25A0187, dated September 18, 1997; 
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 (d) 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 failure of the attachment installation of the forward 
lavatory during an emergency landing, which could result in injury 
to the crew and passengers, accomplish the following:
    (a) For passenger airplanes identified in Boeing Service 
Bulletin 757-25-0181, dated June 26, 1997: Within 18 months after 
the effective date of this AD, install a doubler to the upper 
attachment installation of the forward lavatory in accordance with 
Boeing Service Bulletin 757-25-0181, dated June 26, 1997.
    (b) For freighter airplanes identified in Boeing Alert Service 
Bulletin 757-25A0187, dated September 18, 1997: Within 18 months 
after the effective date of this AD, install floor panel inserts, a 
retention fitting assembly, and a doubler assembly to the lower 
attachment installation of the forward lavatory, in accordance with 
Boeing Alert Service Bulletin 757-25A0187, dated September 18, 1997.
    (c) As of the effective date of this AD, no person shall install 
a floor panel, part number 141N5410-12 or 141N5410-28, on any 
airplane.
    (d) An alternative method of compliance or adjustment of the 
compliance time that

[[Page 26106]]

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.

    (e) Special flight permits may be issued in accordance with 
sections 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 May 5, 1998.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-12517 Filed 5-11-98; 8:45 am]
BILLING CODE 4910-13-U