[Federal Register Volume 63, Number 56 (Tuesday, March 24, 1998)]
[Proposed Rules]
[Pages 14047-14049]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-7524]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-21-AD]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model DC-9 and DC-9-
80 Series Airplanes, Model MD-88 Airplanes, and C-9 (Military) Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
[[Page 14048]]
directive (AD) that is applicable to certain McDonnell Douglas Model
DC-9 and DC-9-80 series airplanes, Model MD-88 airplanes, and C-9
(military) series airplanes. This proposal would require a one-time
visual inspection to detect fatigue cracking of the lower left nose of
certain longerons and the attaching frames; repair, if necessary; and
installation of a preventive modification. The proposal also would
require installation of a preventive modification. This proposal is
prompted by several reports of fatigue cracking of certain longerons
and the attaching frames. The actions specified by the proposed AD are
intended to prevent such fatigue cracking, which could result in
reduced structural integrity of the fuselage, and consequent loss of
pressurization of the airplane.
DATES: Comments must be received by May 8, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 97-NM-21-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056. Comments may be inspected at this location
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal
holidays.
The service information referenced in the proposed rule may be
obtained from The Boeing Company, Douglas Products Division, 3855
Lakewood Boulevard, Long Beach, California 90846, Attention: Technical
Publications Business Administration, Dept. C1-L51 (2-60). This
information may be examined 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.
FOR FURTHER INFORMATION CONTACT: Brent Bandley, Aerospace Engineer,
Airframe Branch, ANM-120L; FAA, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone
(562) 627-5237; 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 notice may be changed in
light of the comments received.
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 notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 97-NM-21-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. 97-NM-21-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received reports indicating that cracking of the
fuselage longerons-to-frame attachment holes occurred on three
McDonnell Douglas Model DC-9 series airplanes. The cracking of the
longeron segments has been attributed to fatigue. The fatigue cracking
was found between longerons 22 though 26 on the left side at stations
Y=160.000 and Y=200.000. These airplanes had accumulated between 59,110
and 74,445 total flight cycles. Such fatigue cracking, if not
corrected, could result in reduced structural integrity of the
fuselage, and consequent loss of pressurization of the airplane.
Similar Airplanes
The fuselage longerons-to-frame attachments of Model DC-9 series
airplanes are similar to those of McDonnell Douglas Model DC-9-80
series airplanes, Model MD-88 airplanes, and C-9 (military) series
airplanes; therefore, these models also may be subject to this same
unsafe condition.
Explanation of Relevant Service Information
The FAA has reviewed and approved McDonnell Douglas DC-9 Service
Bulletin 53-256, dated August 12, 1993, and Revision 1, dated November
29, 1994 (for Model DC-9 series airplanes), and MD-80 Service Bulletin
53-265, dated June 13, 1994 (for Model DC-9-80 series airplanes and MD-
88 airplanes). These service bulletins describe procedures for a one-
time visual inspection to detect cracking of the lower left nose of
longerons 22 through 26 and the attaching frames at stations Y=160.000
and Y=200.000. The service bulletins also provide procedures for a
preventive modification (installation of clips and doublers under
longeron flanges and shims longeron) to relieve preloads. Additionally,
the service bulletins reference the applicable Structural Repair Manual
for repairs, if necessary.
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 require a one-time visual inspection to detect
cracking of the lower left nose of longerons 22 through 26 and the
attaching frames at stations Y=160.000 and Y=200.000. The proposed rule
also would require accomplishment of a preventive modification, and
repair of any cracking detected. The actions would be required to be
accomplished in accordance with the applicable service bulletin
described previously.
Cost Impact
There are approximately 2,000 Model DC-9, Model DC-9-80, and C-9
(military) series airplanes, and Model MD-88 airplanes of the affected
design in the worldwide fleet. The FAA estimates that 1,200 airplanes
of U.S. registry would be affected by this proposed AD, that it would
take approximately 25 work hours per airplane to accomplish the
proposed actions, and that the average labor rate is $60 per work hour.
Based on these figures, the cost impact of the proposed AD on U.S.
operators is estimated to be $1,800,000, or $1,500 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.
Regulatory Impact
The regulations proposed herein would 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
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various levels of government. Therefore, in accordance with Executive
Order 12612, it is determined that this proposal would not have
sufficient federalism implications to warrant the preparation of a
Federalism Assessment.
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 adding the following new
airworthiness directive:
McDonnell Douglas: Docket 97-NM-21-AD.
Applicability: Model DC-9-10, -20, -30, -40, -50 and C-9
(military) series airplanes, as listed in McDonnell Douglas DC-9
Service Bulletin 53-256, Revision 1, dated November 29, 1994; 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 MD-88 airplanes, as listed in McDonnell
Douglas MD-80 Service Bulletin 53-265, dated June 13, 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 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 fatigue cracking of longerons 22 through 26 and the
attaching frames, which could result in reduced structural integrity
of the fuselage, and consequent loss of pressurization of the
airplane; accomplish the following:
(a) Prior to the accumulation of 40,000 total landings, or
within 6,000 landings after the effective date of this AD, whichever
occurs later: Perform a visual inspection to detect cracking of the
left lower nose of longerons 22 through 26 (inclusive) and the
respective attaching frames at station frames Y=160.000 and
Y=200.000; in accordance with McDonnell Douglas DC-9 Service
Bulletin 53-256, dated August 12, 1993, or Revision 1, dated
November 29, 1994 [for Models DC-9, -10, -20, -30, -40, -50, and C-9
(military) series airplanes]; or McDonnell Douglas MD-80 Service
Bulletin 53-265, dated June 13, 1994 (for Model DC-9-81, -82, -83,
and -87 series airplanes, and MD-88 airplanes); as applicable.
(1) If no cracking is detected: Prior to further flight, install
clips and doublers under the longeron flanges and shim the longerons
in accordance with the applicable service bulletin.
(2) If any cracking is detected: Prior to further flight, repair
the cracks and install clips and doublers under the longeron flanges
and shim the longerons in accordance with the applicable service
bulletin.
(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 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Manager, Los Angeles ACO.
(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.
Issued in Renton, Washington, on March 17, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-7524 Filed 3-23-98; 8:45 am]
BILLING CODE 4910-13-U
