[Federal Register Volume 63, Number 171 (Thursday, September 3, 1998)]
[Proposed Rules]
[Pages 46934-46936]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-23739]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-71-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-11 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 MD-11 series airplanes. 
This proposal would require a one-time visual inspection to detect 
discrepancies of the seat tracks and adjacent structure underneath 
lavatories, and repair, if necessary. This proposal also would require 
installation of a non-metallic barrier on the bottom of each lavatory 
foot fitting, and replacement of existing seat track fittings with new 
seat track fittings. This proposal is prompted by reports of galvanic 
corrosion found on the seat tracks at attachment points under certain 
lavatories. The actions specified by the proposed AD are intended to 
prevent corrosion of seat tracks and adjacent structure. Corrosion of 
the seat tracks and adjacent structure could result in shifting of 
lavatories, which could lead to injury of passengers and crew, as well 
as damage to aircraft structure and systems.

DATES: Comments must be received by October 19, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-71-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 The Boeing Company, Douglas Products Division, 3855 
Lakewood Boulevard, Long Beach, California 90846, Attention: Technical 
Publications Business Administration, Dept. C1-L51 (2-60). This 
information may be examined at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington or at the FAA, Transport 
Airplane Directorate, Los Angeles Aircraft

[[Page 46935]]

Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: David Hsu, Aerospace Engineer,Airframe 
Branch, ANM-120L, FAA, Transport Airplane Directorate, Los Angeles 
Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, 
California 90712-4137; telephone (562) 627-5323; fax (562) 627-5210.

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-71-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. 98-NM-71-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports of occurrences on six McDonnell 
Douglas MD-11 series airplanes of galvanic corrosion of the seat tracks 
under certain lavatories. Investigation revealed that the corrosion 
developed at the attachment points between the seat tracks and 
lavatories. Further investigation has revealed that the design of the 
attachment system allows dissimilar metals to come in contact with each 
other, causing galvanic corrosion. In some cases, the corrosion caused 
the seat track attachments for the lavatory to become ineffective. This 
condition, if not corrected, could result in shifting of lavatories, 
which could lead to injury to passengers and crew, as well as damage to 
airplane structure and systems.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Service 
Bulletin MD11-53-043, Revision 02, dated May 28, 1996. This service 
bulletin describes procedures for installation of a non-metallic 
barrier on the bottom of each lavatory foot fitting, and replacement of 
existing seat track fittings with new seat track fittings. 
Accomplishment of the actions specified in the McDonnell Douglas 
service bulletin is intended to adequately address the identified 
unsafe condition. This service bulletin references JAMCO Service 
Bulletin MD11-25-1010, dated July 12, 1994, as an additional source of 
service information for accomplishment of the installation and 
replacement.

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 McDonnell Douglas service bulletin described previously. The 
actions are required to be accomplished in accordance with the service 
bulletin described previously, except as discussed below. The proposed 
AD also would require that operators perform a one-time visual 
inspection to detect discrepancies (i.e., corrosion and breakage) of 
the seat tracks and adjacent structure underneath the subject 
lavatories.

Differences Between Proposed Rule and Service Bulletin Information

    Operators should note that the service bulletins do not provide 
information regarding a one-time visual inspection to detect 
discrepancies (i.e., corrosion and breakage) of the seat tracks and 
adjacent structure underneath lavatories. However, this proposal would 
require a one-time visual inspection of certain areas described in the 
JAMCO service bulletin, where lavatories are installed or were 
previously installed. Additionally, as the service bulletins do not 
provide inspection procedures they also do not provide repair 
procedures. However, this proposal would require that repair conditions 
be dispositioned prior further flight, in accordance with the McDonnell 
Douglas MD-11 Structural Repair Manual, or in accordance with a method 
approved by the Manager, Los Angeles Aircraft Certification Office. The 
FAA finds that this visual inspection to detect discrepancies (i.e., 
corrosion and breakage) is necessary, so that the corroded area is 
repaired prior to installation of new seat track fittings.

Cost Impact

    There are approximately 143 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 46 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
40 work hours per airplane to accomplish the proposed inspection, 
installation, and replacement, and that the average labor rate is $60 
per work hour. Required parts would cost less than $1,000 per airplane. 
Based on these figures, the cost impact of the proposed AD on U.S. 
operators is estimated to be a maximum of $156,400, or $3,400 per 
airplane.
    The cost impact figure discussed above is 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.

[[Page 46936]]

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:

McDonnell Douglas: Docket 98-NM-71-AD.

    Applicability: Model MD-11 series airplanes, as listed in 
McDonnell Douglas Service Bulletin MD-11-53-043, Revision 02, dated 
May 28, 1996; 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 detect and correct corrosion of seat tracks and adjacent 
structure, which could result in shifting of lavatories causing 
injury to passengers and crew, as well as damage to aircraft 
structure and systems, accomplish the following:
    (a) Within 15 months after the effective date of this AD, 
conduct a visual inspection to detect discrepancies (i.e., corrosion 
and breakage) of the seat tracks and adjacent structure at the 
lavatory locations defined in JAMCO Service Bulletin MD-11-25-1010, 
dated July 12, 1994.
    (1) If no discrepancy is detected, prior to further flight, 
install a non-metallic barrier on the bottom of each lavatory foot 
fitting and replace existing seat track fittings with new fittings, 
in accordance with McDonnell Douglas Service Bulletin MD-11-53-043, 
Revision 02, dated May 28, 1996.
    (2) If any discrepancy is detected, prior to further flight, 
repair in accordance with the McDonnell Douglas MD-11 Structural 
Repair Manual, or in accordance with a method approved by the 
Manager, Los Angeles Aircraft Certification Office (ACO), FAA, 
Transport Airplane Directorate. Prior to further flight following 
accomplishment of the repair, install a non-metallic barrier on the 
bottom of each lavatory foot fitting and replace existing seat track 
fittings with new fittings, in accordance with McDonnell Douglas 
Service Bulletin MD-11-53-043, Revision 02, dated May 28, 1996.
    (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, Los Angeles ACO. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Los Angeles ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (c) 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 August 28, 1998.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-23739 Filed 9-2-98; 8:45 am]
BILLING CODE 4910-13-U