[Federal Register Volume 63, Number 27 (Tuesday, February 10, 1998)]
[Rules and Regulations]
[Pages 6639-6642]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-3263]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-12-AD; Amendment 39-10320; AD 98-04-07]
RIN 2120-AA64
Airworthiness Directives; McDonnell Douglas Model DC-9 and DC-9-
80 Series Airplanes, and C-9 (Military) Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to certain McDonnell Douglas Model DC-9 and C-9
(military) series airplanes, that currently requires eddy current or
dye penetrant inspection for cracks in the upper fuselage skin in the
area of the aft pressure bulkhead tee. This amendment requires new
improved repetitive inspections and follow-on actions, and expands the
applicability of the existing AD to include additional airplanes. This
amendment is prompted by additional reports of fatigue cracking and
improperly seated attachments in the upper fuselage skin in the area of
the aft pressure bulkhead tee. The actions specified in this AD are
intended to detect and correct such fatigue cracking, which could
result in rapid decompression of the fuselage and consequent reduced
structural integrity of the airplane.
DATES: Effective February 25, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of February 25, 1998.
Comments for inclusion in the Rules Docket must be received on or
before April 13, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-12-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056.
The service information referenced in this AD 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, 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: Wahib Mina, Aerospace Engineer,
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification
Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone
(562) 627-5324; fax (562) 627-5210.
SUPPLEMENTARY INFORMATION: On May 19, 1982, the FAA issued AD 81-26-03
R1, amendment 39-4394 (47 FR 23697, June 1, 1982), applicable to
certain McDonnell Douglas Model DC-9 and C-9 (military) series
airplanes, to require eddy current or dye penetrant inspection for
cracks in the upper fuselage skin in the area of the aft pressure
bulkhead tee. That action was prompted by reports of fatigue cracking
in the upper skin and improperly seated
[[Page 6640]]
attachments in the upper skin splice area at the fuselage aft pressure
bulkhead tee between longerons 14 left and 14 right. The actions
required by that AD are intended to prevent such fatigue cracking,
which could result in structural failure of the fuselage shell, and
consequent rapid decompression of the airplane.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, the FAA has received reports of
additional fatigue cracking and improperly seated attachments in the
subject area on McDonnell Douglas Model DC-9 series airplanes. These
airplanes had accumulated between 57,485 and 67,755 total flight
cycles. The FAA has determined that accomplishment of the inspections
required by AD 81-26-03 R1 does not adequately preclude fatigue
cracking of the upper skin splice on the aft pressure bulkhead of the
fuselage. Such fatigue cracking, if not detected and corrected in a
timely manner, could result in rapid decompression of the fuselage and
consequent reduced structural integrity of the airplane.
The subject area on certain McDonnell Douglas Model DC-9-80 and C-9
(military) series airplanes is identical to that on the affected Model
DC-9 series airplanes. Therefore, all of these airplanes may be subject
to the same unsafe condition.
Explanation of Relevant Service Information
Subsequent to the finding of this new cracking, the manufacturer
issued, and the FAA reviewed and approved, McDonnell Douglas Alert
Service Bulletin DC9-53A147, Revision 05, dated November 24, 1997,
including Service Sketch 3145B and Service Sketch 3174C (both undated).
The revised alert service bulletin describes new, improved procedures
for repetitive high frequency eddy current (HFEC) inspections to detect
cracks of the upper skin splice area at the tee cap on the aft fuselage
pressure bulkhead between longerons 14 left and 14 right; and
installation of an interim repair, or replacement of failed fasteners
with new fasteners, if necessary. The revised alert service bulletin
also provides for an optional terminating permanent repair, which
eliminates the need for the repetitive inspections. In addition, the
revised alert service bulletin expands the effectivity listing to
include additional airplanes that are subject to the addressed unsafe
condition.
Explanation of Requirements of Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of this same type design, this AD
supersedes AD 81-26-03 R1. This AD requires new, improved repetitive
HFEC inspections to detect cracks in the upper skin splice area at the
tee cap on the aft fuselage pressure bulkhead between longerons 14 left
and 14 right; and installation of an interim repair, or replacement of
failed fasteners with new fasteners, if necessary. The AD also provides
for an optional terminating permanent repair, which constitutes
terminating action for the repetitive inspection requirements. In
addition, the AD expands the applicability of the existing AD to
include additional airplanes. The actions would be required to be
accomplished in accordance with the alert service bulletin described
previously.
Differences Between the AD and the Relevant Service Information
Operators should note that this AD differs from the referenced
alert service bulletin in that it requires an initial visual inspection
of the fuselage upper skin splice at the aft pressure bulkhead between
longerons 14 left and 14 right to determine if an internal production
titanium doubler has been installed. The referenced alert service
bulletin describes procedures for inspection of airplanes on which the
doubler has been installed; however, it does not describe procedures
for such inspection of airplanes on which the doubler has not been
installed.
The FAA has received reports of widespread fatigue-related cracking
on airplanes that had been inspected previously in accordance with AD
81-26-03 R1, and on which an internal production titanium doubler had
not been installed. In light of this, the FAA finds that an initial
one-time visual inspection is necessary to determine if a doubler has
been installed.
In addition, for airplanes on which the subject doubler has not
been installed, the AD would require a visual inspection of the subject
area to determine if an interim or permanent repair has been installed;
and follow-on actions, if necessary. (These follow-on actions include
repetitive HFEC inspections, replacement of failed fasteners, and
accomplishment of an interim repair.)
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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 that
summarizes each FAA-public contact concerned with the substance of this
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 98-NM-12-AD.'' The postcard will be date stamped and
returned to the commenter.
Regulatory Impact
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.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an
[[Page 6641]]
emergency regulation under DOT Regulatory Policies and Procedures (44
FR 11034, February 26, 1979). If it is determined that this emergency
regulation otherwise would be significant under DOT Regulatory Policies
and Procedures, a final regulatory evaluation will be prepared and
placed in the Rules Docket. A copy of it, if filed, 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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-4394 (47 FR
23697, June 1, 1982), and by adding a new airworthiness directive (AD),
amendment 39-10320, to read as follows:
98-04-07 McDonnell Douglas: Amendment 39-10320. Docket 98-NM-
12-AD. Supersedes AD 81-26-03 R1, Amendment 39-4394.
Applicability: Model DC-9-10, -20, -30, -40, -50 series
airplanes, Model DC-9-81 (MD-81) and DC-9-82 (MD-82) series
airplanes, and C-9 (military) series airplanes; as listed in
McDonnell Douglas Alert Service Bulletin DC9-53A147, Revision 05,
dated November 24, 1997; 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 (f) 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 detect and correct fatigue cracking in the upper fuselage
skin in the area of the aft pressure bulkhead tee, which could
result in rapid decompression of the fuselage and consequent reduced
structural integrity of the airplane, accomplish the following:
Note 2: Where there are differences between the alert service
bulletin and the AD, the AD prevails.
(a) Prior to the accumulation of 30,000 total landings, or
within 25 days after the effective date of this AD, whichever occurs
later, perform a visual inspection of the fuselage upper skin splice
at the aft pressure bulkhead between longerons 14 left and 14 right
to determine if an internal production titanium doubler has been
installed.
(1) If results of the visual inspection reveal that an internal
production titanium doubler has not been installed, prior to further
flight, perform a visual inspection of the fuselage upper skin
splice area at the aft pressure bulkhead between longerons 14 left
and 14 right to determine if a permanent repair has been installed
in accordance with McDonnell Douglas Alert Service Bulletin DC9-
53A147, Revision 2, dated June 3, 1981; Revision 3, dated November
22, 1981; Revision 4, dated October 25, 1983; or Revision 05, dated
November 24, 1997.
(i) If a permanent repair has been installed, no further action
is required by this AD.
(ii) If a permanent repair has not been installed, and if a dye
penetrant or HFEC inspection has been accomplished in accordance
with AD 81-26-03 R1, within 4,000 landings following accomplishment
of the last dye penetrant or HFEC inspection required by AD 81-26-03
R1, or within 90 days after the effective date of this AD, whichever
occurs later, perform an HFEC inspection to detect skin cracks or
failed fasteners of the unmodified area, in accordance with the
Accomplishment Instructions of the alert service bulletin.
(iii) If a permanent repair has not been installed, and if a dye
penetrant or HFEC inspection has not been accomplished in accordance
with AD 81-26-03 R1, prior to further flight, perform a high
frequency eddy current (HFEC) inspection to detect skin cracks or
failed fasteners of the unmodified area, in accordance with the
Accomplishment Instructions of the alert service bulletin.
(2) If results of the visual inspection reveal that an internal
production titanium doubler has been installed, perform an HFEC
inspection to detect skin cracks or failed fasteners of the upper
skin splice area at the tee cap of the aft fuselage pressure
bulkhead between longerons 14 left and 14 right, in accordance with
the Accomplishment Instructions of the alert service bulletin at the
time specified in paragraph (a)(2)(i) or (a)(2)(ii) of this AD, as
applicable.
(i) For airplanes that have been previously inspected using LFEC
techniques or have not been previously inspected, in accordance with
AD 81-26-03 R1: Inspect within 90 days following accomplishment of
the visual inspection required by paragraph (a) of this AD.
(ii) For airplanes that have been inspected previously using
HFEC or dye penetrant techniques, in accordance with AD 81-26-03 R1:
Inspect within 4,000 landings following accomplishment of the last
HFEC or dye penetrant inspection required by AD 81-20-03 R1, or
within 90 days following accomplishment of the visual inspection
required by paragraph (a) of this AD, whichever occurs later.
(b) If no skin crack or failed fastener is detected during any
inspection required by this AD, repeat the HFEC inspection required
by paragraph (a) of this AD thereafter at intervals not to exceed
4,000 landings.
(c) If any failed fastener with no skin crack is detected during
any inspection required by this AD, prior to further flight, replace
the failed fastener with a new fastener, in accordance with the
Accomplishment Instructions of McDonnell Douglas Alert Service
Bulletin DC9-53A147, Revision 05, dated November 24, 1997, including
Service Sketch 3145B and Service Sketch 3174C (both undated). Repeat
the HFEC inspection required by paragraph (a) of this AD thereafter
at intervals not to exceed 4,000 landings.
(d) If any skin crack is detected during any inspection required
by this AD, prior to further flight, accomplish the interim repair
in accordance with the Accomplishment Instructions of McDonnell
Douglas Alert Service Bulletin DC9-53A147, Revision 05, dated
November 24, 1997, including Service Sketch 3145B and Service Sketch
3174C (both undated). For the unmodified area, repeat the HFEC
inspection required by paragraph (a) of this AD thereafter at
intervals not to exceed 4,000 landings.
(e) Accomplishment of the permanent repair in accordance with
the Accomplishment Instructions of McDonnell Douglas Alert Service
Bulletin DC9-53A147, Revision 05, dated November 24, 1997, including
Service Sketch 3145B and Service Sketch 3174C (both undated),
constitutes terminating action for the repetitive inspection
requirements of this AD.
Note 3: The permanent repair is required by AD 96-10-11,
amendment 39-9618 (61 FR 24675, May 16, 1996) as part of the DC-9/
MD-80 Aging Aircraft Service Action Requirements Document.
(f) 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 4: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Los Angeles ACO.
(g) 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.
(h) Except as provided by paragraphs (a) and (a)(1) of this AD,
the inspections, replacement, interim repair, and permanent repair,
if accomplished, shall be done in
[[Page 6642]]
accordance with McDonnell Douglas Alert Service Bulletin DC9-53A147,
Revision 05, dated November 24, 1997, including Service Sketch 3145B
and Service Sketch 3174C (both undated). 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 The Boeing Company, Douglas Products Division, 3855
Lakewood Boulevard, Long Beach, California 90846, Attention:
Technical Publications Business Administration, Dept. C1-L51 (2-60).
Copies may be inspected at the FAA, Transport Airplane Directorate,
1601 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.
(i) This amendment becomes effective on February 25, 1998.
Issued in Renton, Washington, on February 4, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-3263 Filed 2-9-98; 8:45 am]
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