[Federal Register Volume 68, Number 153 (Friday, August 8, 2003)]
[Rules and Regulations]
[Pages 47202-47204]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-19681]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-357-AD; Amendment 39-13253; AD 2003-16-01]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-11 and -11F 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain McDonnell Douglas Model MD-11 and -11F airplanes, 
that requires modifying the overhead instrument lighting by relocating 
the dimmer control unit and revising the wire routing. This action is 
necessary to prevent overheating and internal component failure of the 
dimmer control unit of the overhead instrument lighting, which could 
result in smoke and/or fire in the flight compartment. This action is 
intended to address the identified unsafe condition.

DATES: Effective September 12, 2003.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 12, 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). This information may 
be examined at the Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington; 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: Natalie Phan-Tran, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California 
90712-4137; telephone (562) 627-5343; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain McDonnell Douglas Model 
MD-11 and -11F airplanes was published in the Federal Register on May 
15, 2002 (67 FR 34635). That action proposed to require modifying the 
overhead instrument lighting by relocating the dimmer control unit and 
revising the wire routing.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. The FAA has given due consideration to 
the comments received.
    One commenter states no objection to the proposed AD.

Request To Ensure That Relocation of Switch Would Eliminate Unsafe 
Condition

    Two commenters express concern about whether relocating the dimmer 
control unit for the overhead instrument light from its existing 
location to a better-ventilated area will adequately address the unsafe 
condition. The commenters note that the proposed AD states that 
inadequate heat dissipation in the existing location contributed to the 
overheating and internal component failure of the dimmer control unit. 
Both commenters question whether the proposed AD is addressing the root 
cause of the smoke in the flight deck--i.e., the failure of the 
internal components in the dimmer control unit. The commenters noted 
that a related AD, AD 98-24-02, amendment 39-10889 (63 FR 63402, 
November 13, 1998), requires a modification of the dimmer control unit 
to replace the capacitor in the dimmer control unit with a new 
capacitor having a higher temperature rating. One of the commenters 
notes, however, that, even after accomplishment of AD 98-24-02, several 
operators have reported events involving smoke in the flight deck and 
failure of the new capacitors. Both commenters question whether 
adequate research has been done to ensure that relocating the dimmer 
control unit will preclude the overheating condition that can lead to 
smoke in the flight deck. One of the commenters states that the 
airplane manufacturer has informed it that no on-aircraft temperature 
readings were taken either before or after relocating the dimmer 
control unit. That commenter requests that such on-aircraft testing be 
accomplished before the FAA proceeds with this rulemaking action.
    We infer that the commenters want us to postpone the proposed 
rulemaking until further testing and analysis are done to ensure that 
the proposed action

[[Page 47203]]

will address the unsafe condition. We concur with the commenters' 
request and have delayed issuance of this final rule until now. Testing 
was performed on a Model MD-11 airplane to measure the temperature of 
the dimmer control unit in the existing and new locations. The dimmer 
control unit had been modified to incorporate the new capacitor. 
Internal and external temperatures of the dimmer control unit, 
including temperature of the new capacitor, were recorded every 10 
seconds for an hour and forty minutes. Analysis of the test results 
revealed that the capacitor in the dimmer control unit was heated to 
approximately 90 percent of its temperature rating in its old location 
versus approximately 60 percent of its temperature rating in the new 
location. These results support the hypothesis that the lack of heat 
dissipation in the existing location of the dimmer control unit 
contributes to the overheating condition and capacitor failure; moving 
the dimmer control unit to the new location should correct this unsafe 
condition. No change to the final rule is necessary in this regard.
    Another commenter states that it does not agree that relocating the 
dimmer control unit will be effective in preventing the overheating 
condition. The commenter states that increased ventilation may ``fan 
the flames.'' The commenter states that it has developed and tested a 
modified model of the dimmer control unit, for which the FAA has 
granted a Parts Manufacturing Approval (PMA). The commenter states that 
redesign of the circuitry in this modification eliminates the 
possibility of capacitor overheating. The commenter requests that we 
consider its modified dimmer control unit as a proposed corrective 
action.
    We do not concur. Testing has shown that, rather than ``fanning the 
flames,'' relocating the dimmer control unit to a better ventilated 
area will ensure that airflow is increased and heat is dissipated more 
effectively, which will alleviate the overheating condition. The 
testing described previously supports this action. Further, we 
recognize that, in order to obtain a PMA to replace or modify a type 
certificated product, a part is required to meet the airworthiness 
requirements of the Federal Aviation Regulations (FARs) applicable to 
the airplane model on which the part is to be installed. The part 
approved by the PMA must have been subjected to all necessary tests and 
computations as one method of showing compliance with the applicable 
airworthiness requirements. However, the airworthiness requirements 
approval for installing a part approved by a PMA may not address unsafe 
conditions that are likely to be encountered in service operations. In 
addition, we require the holder of the type certificate for the subject 
airplane model to make the necessary design changes to correct an 
unsafe condition by submitting appropriate design changes for approval 
and, upon the approval of the design changes, make available the 
descriptive data covering the changes to all operators of airplanes 
previously certificated under the type certificate. For these reasons, 
we cannot mandate a part approved by a third-party PMA to correct an 
unsafe condition. However, per the provisions of paragraph (b) of this 
AD, an operator may submit a request for approval of the installation 
of a modified dimmer control unit, such as the one to which the 
commenter refers, as an alternative method of compliance (AMOC) with 
this AD. The request should include adequate data to justify that 
installation of the modified dimmer control unit will provide an 
acceptable level of safety. No change to the final rule is necessary in 
this regard.

Request To Consider Parallel Rulemaking for Other Airplanes and Other 
Areas

    One commenter is concerned that the overheating condition and 
capacitor failures in the dimmer control unit may also occur on other 
airplane models, such as McDonnell Douglas Model MD-10 and DC-10 
airplanes, or on other dimmer control units installed in locations 
other than the overhead area. The commenter notes that capacitor 
failures within the dimmer control units on other airplane models have 
been observed and tracked for identification of the cause. The 
commenter provides data on these other occurrences.
    We have reviewed the data provided by the commenter. These data 
reveal that capacitor failures in the overhead dimmer control unit on 
other airplanes do not represent systemic failures, and capacitor 
failures at other locations on the airplane are not related to 
overheating and are not systemic failures. No change to the final rule 
is necessary in this regard.

Conclusion

    After careful review of the available data, including the comments 
noted above, 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. However, for clarity and consistency in this final rule, we 
have retained the language of the NPRM regarding that material.

Change to Labor Rate Estimate

    After the proposed AD was issued, we reviewed the figures we use to 
calculate the labor rate to do the required actions. To account for 
various inflationary costs in the airline industry, we find it 
appropriate to increase the labor rate used in these calculations from 
$60 per work hour to $65 per work hour. The economic impact 
information, below, has been revised to reflect this increase in the 
specified hourly labor rate.

Cost Impact

    There are approximately 195 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 74 airplanes of U.S. registry 
will be affected by this AD, that it will take approximately 4 work 
hours per airplane to accomplish the actions, and that the average 
labor rate is $65 per work hour. Required parts will cost approximately 
$101 per airplane. Based on these figures, the cost impact of the AD on 
U.S. operators is estimated to be $26,714, or $361 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.

Regulatory Impact

    The regulations adopted herein will 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 final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT

[[Page 47204]]

Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) 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 final evaluation has been prepared 
for this action and it is contained in the Rules Docket. A copy of it 
may be obtained from the Rules Docket at the location provided under 
the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2003-16-01 McDonnell Douglas: Amendment 39-13253. Docket 2001-NM-
357-AD.

    Applicability: Model MD-11 and -11F airplanes, certificated in 
any category, as listed in McDonnell Douglas Alert Service Bulletin 
MD11-33A071, Revision 01, dated September 24, 2001.

    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 prevent overheating and internal component failure of the 
dimmer control unit of the overhead instrument lighting, which could 
result in smoke and/or fire in the flight compartment, accomplish 
the following:

Modification

    (a) Within 18 months after the effective date of this AD: Modify 
the overhead instrument lighting by relocating the dimmer control 
unit and revising the wire routing, in accordance with McDonnell 
Douglas Alert Service Bulletin MD11-33A071, Revision 01, dated 
September 24, 2001.

Alternative Methods of Compliance

    (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 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 2: 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

    (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.

Incorporation by Reference

    (d) The actions shall be done in accordance with McDonnell 
Douglas Alert Service Bulletin MD11-33A071, Revision 01, dated 
September 24, 2001. This incorporation by reference was approved by 
the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51. Copies 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). Copies may be inspected at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; 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.

Effective Date

    (e) This amendment becomes effective on September 12, 2003.

    Issued in Renton, Washington, on July 29, 2003.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-19681 Filed 8-7-03; 8:45 am]
BILLING CODE 4910-13-P