[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]
BILLING CODE 4910-13-P