[Federal Register Volume 68, Number 39 (Thursday, February 27, 2003)]
[Proposed Rules]
[Pages 9034-9036]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-4587]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-125-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-90-30 
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 all McDonnell Douglas Model MD-90-
30 airplanes. This proposal would require replacing the lanyards on the 
pressure relief door for the thrust reverser with new, improved 
lanyards, and doing associated modifications. This action is necessary 
to ensure that the lanyards on the pressure relief door have adequate 
strength. Lanyards of inadequate strength could allow the pressure 
relief door to detach from the thrust reverser in the event that an 
engine bleed air duct bursts, which could result in the detached door 
striking and damaging the horizontal stabilizer, and consequent reduced 
controllability of the airplane. This action is intended to address the 
identified unsafe condition.

DATES: Comments must be received by April 14, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-125-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-125-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must

[[Page 9035]]

be formatted in Microsoft Word 97 for Windows or ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Aircraft Group, Long Beach Division, 
3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data 
and Service Management, Dept. C1-L5A (D800-0024); and BF Goodrich, 850 
Lagoon Drive, Chula Vista, California 91910-2098. This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT: William S. Bond, Aerospace Engineer, 
Propulsion Branch, ANM-140L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 
telephone (562) 627-5253; 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-125-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. 2001-NM-125-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report indicating that, on all McDonnell 
Douglas Model MD-90-30 airplanes, the lanyards on the pressure relief 
door for the thrust reversers do not meet the certification 
requirements for strength. Lanyards of inadequate strength could allow 
the pressure relief door to detach from the thrust reverser in the 
event that an engine bleed air duct bursts, which could result in the 
detached door striking and damaging the horizontal stabilizer.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin MD90-78-
048, including Evaluation Form, dated February 15, 2001, which 
describes procedures for replacing the lanyards on the pressure relief 
door for the thrust reverser with new, improved lanyards, and doing 
associated modifications.
    Boeing Service Bulletin MD90-78-048 refers to International Aero 
Engines Service Bulletin V2500-NAC-78-0184, dated February 16, 2001, as 
the appropriate source of service information for replacing the door 
lanyards and doing the associated modifications. The procedures in that 
service bulletin include removing the pressure relief door, replacing 
the door lanyard assemblies with new, improved assemblies, modifying 
the pressure relief door (including replacing existing brackets with 
new brackets and reidentifying the door with a new part number), 
modifying the lower track beam (including removing terminals, replacing 
the aft quick-release pin with a new pin, and reidentifying the beam 
with a new part number), modifying the heat shield on the lanyard 
assembly attach lugs, and re-installing the pressure relief door.
    Accomplishment of the actions 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 actions specified in 
the service bulletins described previously, except as discussed below.

Clarification of Applicability

    Boeing Service Bulletin MD90-78-048 specifies an effectivity of 
Model MD-90-30 airplanes ``equipped with V2500-D5 thrust reversers 
prior to serial number 0701001.'' All Model MD-90-30 airplanes are 
equipped with the subject thrust reversers; thus, all Model MD-90-30 
airplanes are subject to this proposed AD.

Differences Between Proposed AD and Service Information

    The service bulletins recommend replacing the door lanyards and 
doing associated modifications at the next scheduled maintenance visit 
when manpower, materials, and facilities are available. The FAA has 
determined that such a non-specific compliance time would not ensure 
that the identified unsafe condition is addressed in a timely manner. 
In developing an appropriate compliance time for this AD, the FAA 
considered not only the manufacturer's recommendation, but also the 
degree of urgency associated with addressing the subject unsafe 
condition, and the time necessary to perform the proposed actions. In 
light of all of these factors, the FAA finds that a compliance time of 
18 months after the effective date of the AD for completing the 
proposed actions is warranted, in that it represents an appropriate 
interval of time allowable for affected airplanes to continue to 
operate without compromising safety.

Cost Impact

    There are approximately 110 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 21 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
8 work hours per airplane to accomplish the proposed actions, and that 
the average labor rate is $60 per work hour. Required parts would be 
provided at no cost to the operator. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be $10,080, 
or $480 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

[[Page 9036]]

action, and that no operator would accomplish those actions in the 
future if this proposed AD were not adopted. The cost impact figures 
discussed in AD rulemaking actions represent only the time necessary to 
perform the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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:

McDonnell Douglas: Docket 2001-NM-125-AD.
    Applicability: All Model MD-90-30 airplanes; 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 (c) 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 ensure that the lanyards on the pressure relief door for the 
thrust reverser have adequate strength so that the door will not 
detach from the thrust reverser in the event that an engine bleed 
air duct bursts, which could result in the door striking and 
damaging the horizontal stabilizer, accomplish the following:

Replacement of Lanyards on the Thrust Reverser Pressure Relief Door

    (a) Within 18 months after the effective date of the AD, replace 
the lanyards on the pressure relief door for the thrust reverser 
with new, improved lanyards, and accomplish associated 
modifications, per the Accomplishment Instructions of Boeing Service 
Bulletin MD90-78-048, excluding Evaluation Form, dated February 15, 
2001. The associated modifications include removing the pressure 
relief door, modifying the pressure relief door (including replacing 
existing brackets with new brackets and reidentifying the door with 
a new part number), modifying the lower track beam (including 
removing terminals, replacing the aft quick-release pin with a new 
pin, and reidentifying the beam with a new part number), modifying 
the heat shield on the lanyard assembly attach lugs, and re-
installing the pressure relief door.

    Note 2: Boeing Service Bulletin MD90-78-048, excluding 
Evaluation Form, dated February 15, 2001, refers to International 
Aero Engines Service Bulletin V2500-NAC-78-0184, dated February 16, 
2001, for instructions on replacing the lanyards on the pressure 
relief door for the thrust reverser.

Spares

    (b) After the effective date of this AD, no person may install a 
lanyard having part number (01-250) or (01-255) on the pressure 
relief door for the thrust reverser on any airplane.

Alternative Methods of Compliance

    (c) 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 Aircraft Certification 
Office (ACO), FAA. 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

Special Flight Permits

    (d) 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 February 20, 2003.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-4587 Filed 2-26-03; 8:45 am]
BILLING CODE 4910-13-P