[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]
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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.
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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
