[Federal Register Volume 59, Number 240 (Thursday, December 15, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-30144]


[[Page Unknown]]

[Federal Register: December 15, 1994]


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


DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-87-AD; Amendment 39-9090; AD 94-25-06]

 

Airworthiness Directives; McDonnell Douglas Model DC-9-80 Series 
Airplanes and Model MD-88 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Model DC-9-80 series airplanes and Model MD-88 
airplanes, that requires modification of the engine nose cowls. This 
amendment is prompted by several in-flight incidents in which the 
engine nose cowl separated or nearly separated from the airplane. The 
actions specified by this AD are intended to prevent separation of the 
engine nose cowl from the airplane during severe vibration of the 
engine.

DATES: Effective January 17, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 17, 1995.

ADDRESSES: The service information referenced in this AD may be 
obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach, 
California 90801-1771, Attention: Business Unit Manager, Technical 
Administrative Support, Dept. L51, M.C. 2-98. This information may be 
examined at the Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington; or at the FAA, Transport Airplane Directorate, Los Angeles 
Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, 
California 90712; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Robert Baitoo, Aerospace Engineer, 
Propulsion Branch, ANM-141L, FAA, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California 90712; telephone (310) 627-5245; fax (310) 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 Model DC-9-80 series 
airplanes and Model MD-88 airplanes series airplanes was published in 
the Federal Register on July 27, 1994 (59 FR 38147). That action 
proposed to require modification of the left and right engine nose 
cowls.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter supports the propose rule.
    Several commenters request that the compliance time for the 
accomplishment of the modification be extended from the proposed 8 
months to 12 or 18 months. These commenters state that they would have 
to special schedule their fleet of airplanes to accomplish this 
modification within the proposed compliance time. This would entail 
considerable additional expenses and schedule disruptions. The FAA 
concurs. The FAA's intent was that the modification be accomplished 
during a regularly scheduled maintenance for the majority of the 
affected fleet, when the airplanes would be located at a base where 
special equipment and trained personnel would be readily available, if 
necessary. Based on the information supplied by the commenters, the FAA 
now recognizes that 12 months corresponds more closely to the interval 
representative of most of the affected operators' normal maintenance 
schedules. Paragraph (a) of the final rule has been revised to reflect 
a compliance time of 12 months. The FAA does not consider that this 
extension of an additional 4 months for compliance will adversely 
affect safety.
    Two commenters state that, during accomplishment of the 
modification, they found an interference condition on the engine cowls 
being modified that prevents installation of bolt heads facing forward. 
One commenter states that the final rule of this AD should not be 
released until the McDonnell Douglas MD-80 Alert Service Bulletin A71-
61 is revised to correct procedures relative to this interference 
condition. The FAA infers from these commenters that they would like 
the proposed rule to be revised to cite the latest revision of 
McDonnell Douglas MD-80 Alert Service A71-61. The FAA concurs. Since 
issuance of the proposed rule, the FAA has reviewed and approved 
Revision 1, of McDonnell Douglas Alert Service Bulletin, dated October 
4, 1994. Revision 1 allows the installation of bolts from the engine 
flange side when interference with the Hi-Lok bolts exist. The FAA has 
revised paragraph (a) of the final rule to reflect the latest revision 
to the alert service bulletin as an additional source of service 
information.
    The FAA has recently reviewed the figures it has used over the past 
several years in calculating the economic impact of AD activity. In 
order to account for various inflationary costs in the airline 
industry, the FAA has determined that it is necessary to increase the 
labor rate used in these calculations from $55 per work hour to $60 per 
work hour. The economic impact information, below, has been revised to 
reflect this increase in the specified hourly labor rate.
    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that some operators 
may misunderstand the legal effect of AD's on airplanes that are 
identified in the applicability provision of the AD, but that have been 
altered or repaired in the area addressed by the AD. Under these 
circumstances, at least one operator appears to have incorrectly 
assumed that its airplane was not subject to the AD. On the contrary, 
all airplanes identified in the applicability provision of an AD are 
legally subject to the AD. If an airplane has been altered or repaired 
in the affected area in such a way as to affect compliance with the AD, 
the owner or operator is required to obtain FAA approval for an 
alternative method of compliance with the AD, in accordance with the 
paragraph of each AD that provides for such approvals. A note has been 
added to the final rule to clarify this requirement.
    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 with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    There are approximately 1,062 McDonnell Douglas Model DC-9-80 
series airplanes and Model MD-88 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 540 airplanes of U.S. 
registry will be affected by this AD, that it will take approximately 6 
work hours per airplane to accomplish the required actions, and that 
the average labor rate is $60 per work hour. Required parts will cost 
approximately $100 per airplane. Based on these figures, the total cost 
impact of the AD on U.S. operators is estimated to be $248,400, or $460 
per airplane.
    The FAA has been advised that 74 U.S.-registered airplanes have 
been modified in accordance with the requirement of this AD. Therefore, 
the future economic cost impact of this rule on U.S. operators is now 
only $214,360.
    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    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 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

    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

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

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

94-25-06 McDonnell Douglas: Amendment 39-9090. Docket 94-NM-87-AD.

    -Applicability: Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 
(MD-83), and DC-9-87 (MD-87) series airplanes and Model MD-88 
airplanes; as listed in McDonnell Douglas MD-80 Alert Service 
Bulletin A71-61, Revision 1, dated October 4, 1994; 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 use the authority 
provided in paragraph (b) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition; or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    -Compliance: Required as indicated, unless accomplished 
previously. -
    To prevent the engine nose cowl separating from the airplane 
during severe engine vibration, accomplish the following: -
    (a) Within 12 months after the effective date of this AD, modify 
the left and right engine nose cowls in accordance with McDonnell 
Douglas MD-80 Alert Service Bulletin A71-61, dated May 18, 1994, or 
Revision 1, dated October 4, 1994.

    -Note 2: Modification in accordance with either Figure 1, Figure 
2, or Figure 3 of the alert service bulletin is acceptable for 
compliance with this paragraph.

    -(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, Transport Airplane Directorate. 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.

    -(c) Special flight permits may be issued in accordance with 
Secs. 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. -
    (d) The modification shall be done in accordance with McDonnell 
Douglas MD-80 Alert Service Bulletin A71-61, dated May 18, 1994, or 
McDonnell Douglas MD-80 Alert Service Bulletin, Revision 1, dated 
October 4, 1994. 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 McDonnell Douglas 
Corporation, P.O. Box 1771, Long Beach, California 90801-1771, 
Attention: Business Unit Manager, Technical Administrative Support, 
Dept. L51, M.C. 2-98. Copies may be inspected at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 
at the FAA, Transport Airplane Directorate, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California 
90712; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC. -
    (e) This amendment becomes effective on January 17, 1995.

    Issued in Renton, Washington, on December 2, 1994.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-30144 Filed 12-14-94; 8:45 am]
BILLING CODE 4910-13-U