AD 2003-11-15 R1

AD Final Rules - 031115R1.pdf
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AD Number:
2003-11-15 R1
Document Type:
AD Final Rules
Docket Number:
2003-NM-169-AD
Subject Heading:
Airworthiness Directives; McDonnell Douglas Model MD-90-30 Airplanes
Subject:
Pressure relief door
Status:
Current
Citation:
(Federal Register: December 23, 2003 (Volume 68, Number 246))
Citation Publish Date:
12/23/2003
Effective Date:
01/27/2004
Make:
The Boeing Company
Model:
MD-90-30
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
2003-11-15
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39
Comments:
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[Federal Register: December 23, 2003 (Volume 68, Number 246)]


[Rules and Regulations]


[Page 74171-74172]


From the Federal Register Online via GPO Access [wais.access.gpo.gov]


[DOCID:fr23de03-8]


–––––––––––––––––––––––––––––––––––


DEPARTMENT OF TRANSPORTATION


Federal Aviation Administration


14 CFR Part 39


[Docket No. 2003-NM-169-AD; Amendment 39-13400; AD 2003-11-15 R1]


RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-90-30 Airplanes


AGENCY:
 
Federal Aviation Administration, DOT.


ACTION:
 
Final rule.


–––––––––––––––––––––––––––––––––––


SUMMARY:
 
This amendment revises 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 amendment 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 amendment will 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:
 
Effective January 27, 2004.


The incorporation by reference of Boeing Service Bulletin MD90-78-048, dated February 15,


2001, as listed in the regulations, was approved previously by the Director of the Federal Register as


of July 9, 2003 (68 FR 33355, June 4, 2003).


ADDRESSES:
 
The service information referenced in this AD 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 Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601
2


Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office,


3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal Register, 800


North Capitol Street, NW., suite 700, Washington, DC.


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:
 
A proposal to amend part 39 of the Federal Aviation


Regulations (14 CFR part 39) by revising AD 2003-11-15, amendment 39-13174 (68 FR 33355, June


4, 2003), which is applicable to all McDonnell Douglas Model MD-90-30 airplanes, was published in


the Federal Register on August 21, 2003 (68 FR 50491). The action proposed 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 action also proposed to prohibit installation of certain


pressure relief door lanyards.


Comments


Interested persons have been afforded an opportunity to participate in the making of this


amendment. No comments were submitted in response to the proposal or the FAA's determination of


the cost to the public.


Conclusion


The FAA has determined that air safety and the public interest require the adoption of the rule as


proposed.


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). However, for clarity and consistency in this final rule, we have retained the language of


the NPRM regarding that material.


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 will be affected by this AD. The changes in this action add


no additional economic burden. The current costs for this 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 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.