[Federal Register: August 21, 2003 (Volume 68, Number 162)]
[Proposed Rules]               
[Page 50491-50493]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21au03-20]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-169-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 to revise an existing airworthiness 
directive (AD), applicable to all McDonnell Douglas Model MD-90-30 
airplanes, that currently requires replacing the lanyards on the 
pressure relief door for the thrust reverser with new, improved 
lanyards, and doing associated modifications. The actions specified by 
that AD are intended 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 proposed AD is 
prompted by the fact that a certain paragraph of the existing AD 
prohibits installation of certain part numbers of lanyards; the numbers 
listed in that paragraph correspond to new, improved lanyards that are 
acceptable for installation. This action would correct these part 
numbers to prohibit installation of suspect lanyards while allowing 
installation of the new, improved lanyards. This action is intended to 
address the identified unsafe condition.

DATES: Comments must be received by October 6, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2003-NM-169-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: 
9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must 
contain ``Docket No. 2003-NM-169-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 or 2000 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 Rohr, Inc., 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: Stephen Kolb, Aerospace Engineer, 
Propulsion Branch, ANM-140L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 
telephone (562) 627-5244; 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 2003-NM-169-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. 2003-NM-169-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On May 27, 2003, the FAA issued AD 2003-11-15, amendment 39-13174 
(68 FR 33355, June 4, 2003), applicable to all McDonnell Douglas Model 
MD-90-30 airplanes. That AD requires replacing

[[Page 50492]]

the lanyards on the pressure relief door for the thrust reverser with 
new, improved lanyards, and doing associated modifications. That action 
was prompted by a report indicating that the lanyards on the pressure 
relief door for the thrust reversers on the subject airplanes do not 
meet the certification requirements for strength. The requirements of 
that AD are intended 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. This condition could result in 
reduced controllability of the airplane.

Actions Since Issuance of Previous Rule

    Paragraph (b) of AD 2003-11-15 prohibits installation of pressure 
relief door lanyards having certain part numbers. Since the issuance of 
that AD, the FAA has determined that the part numbers listed in that 
paragraph are incorrect. The numbers in that paragraph are Illustrated 
Parts Catalog numbers that correspond to new, improved lanyard 
assemblies that are acceptable for installation per the requirements of 
the existing AD. Paragraph (b) should have referred to the part numbers 
of the pressure relief door lanyards that paragraph (a) of AD 2003-11-
15 requires to be replaced.

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 revise AD 2003-11-15 to continue to require replacing 
the lanyards on the pressure relief door for the thrust reverser with 
new, improved lanyards, and doing associated modifications. The 
proposed AD would also prohibit installation of certain pressure relief 
door lanyards.

Explanation of Additional Change to Existing Requirements

    We have revised the heading that precedes paragraph (b) of this AD 
from ``Spares'' to ``Parts Installation.'' We find the heading ``Parts 
Installation'' more accurately describes the contents of that 
paragraph.

Changes to 14 CFR Part 39/Effect on the AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance (AMOCs). Because we have now included this material in part 
39, only the office authorized to approve AMOCs is identified in each 
individual AD. However, for clarity and consistency in this proposed 
AD, we have retained the language of the existing AD regarding that 
material.

Change to Labor Rate Estimate

    We have reviewed the figures we have used over the past several 
years to calculate AD costs to operators. To account for various 
inflationary costs in the airline industry, we find it necessary to 
increase the labor rate used in these calculations from $60 per work 
hour to $65 per work hour. The cost impact information, below, reflects 
this increase in the specified hourly labor rate.

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. The proposed changes in this 
action add no additional economic burden. The current costs for this 
proposed AD are repeated for the convenience of affected operators, as 
follows:
    It takes approximately 8 work hours per airplane to accomplish the 
actions currently required by AD 2003-11-15, at an average labor rate 
of $65 per work hour. Required parts are provided at no cost to the 
operator. Based on these figures, the cost impact of the actions 
currently required by AD 2003-11-15 is estimated to be $10,920, or $520 
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. 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 removing amendment 39-13174 (68 FR 
33355, June 4, 2003), and by adding a new airworthiness directive (AD), 
to read as follows:

McDonnell Douglas: Docket 2003-NM-169-AD. Revises AD 2003-11-15, 
Amendment 39-13174.

    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.


[[Page 50493]]


    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, 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 re-identifying 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 re-
identifying 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, 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.

Parts Installation

    (b) After the effective date of this AD, no person may install a 
lanyard having part number (S700M1392A170) or (S700M1392A161) 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 August 15, 2003.
Kyle L. Olsen,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-21414 Filed 8-20-03; 8:45 am]

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