[Federal Register Volume 63, Number 122 (Thursday, June 25, 1998)]
[Rules and Regulations]
[Pages 34585-34587]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-16695]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-203-AD; Amendment 39-10626; AD 98-13-35]
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: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain McDonnell Douglas Model DC-9 and DC-9-80 series
airplanes, Model MD-88 airplanes, and C-9 (military) series airplanes,
that requires repetitive high frequency eddy current inspections of
certain areas of the fuselage to detect cracks of the skin and/or
longeron, and various follow-on actions. This amendment also requires
installation of a preventative modification, which terminates the
repetitive inspections. This amendment is prompted by reports
indicating that, due to material fatigue caused by installation preload
and cabin pressurization cycles, fatigue cracks were found in the skin
and longerons of the fuselage. The actions specified by this AD are
intended to prevent such fatigue cracks, which could result in loss of
the structural integrity of the fuselage and, consequently, lead to
rapid depressurization of the airplane.
DATES: Effective July 30, 1998.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of July 30, 1998.
ADDRESSES: 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 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; or at the Office of the Federal Register, 800
North Capitol Street, NW., suite 700, Washington, DC.
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: 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 McDonnell Douglas Model
DC-9 and DC-9-80 series airplanes, Model MD-88 airplanes, and C-9
(military) series airplanes was published in the Federal Register on
March 7, 1997 (62 FR 10492). That action proposed to require repetitive
high frequency eddy current (HFEC) inspections of the external areas of
the fuselage skin to detect cracks of the skin and/or longeron between
stations Y=160.000 and Y=218.000, and various follow-on actions. That
action also proposed to require the installation of a preventative
modification, which would constitute terminating action for the
repetitive inspection requirements.
Explanation of Changes Made to Proposed AD
Since issuance of the NPRM, the FAA has received a report
indicating that, during inspection of a McDonnell Douglas Model DC-9-32
series airplane, fatigue cracking was found in additional structure
that is within the subject area of the proposed AD (i.e., between
stations Y=160.000 and Y=218.000). The additional area is approximately
10 inches by 6 inches and is directly between areas subject to the
proposed inspection required by this AD. Because
[[Page 34586]]
of the small size of the additional area and its location, the FAA
finds that adding this area to the existing requirements of the final
rule will not increase significantly the inspection burden on
operators. Therefore, in addition to the area between stations
Y=160.000 and Y=218.000 (as specified in McDonnell Douglas DC-9 Service
Bulletin 53-235, which was referenced in the proposed AD as the
appropriate source of service information), the FAA has determined that
the repetitive HFEC inspections also must be conducted in the entire
area between stations Y=160.000 and Y=180.000, longeron 4 left and
longeron 5 left. The FAA has revised paragraph (a) of the final rule
accordingly, and has added one work hour to the cost impact information
below, to account for the additional time necessary to accomplish the
required inspection. In addition, McDonnell Douglas is planning on
revising the referenced service bulletin to coincide with the
requirements of this final rule.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Several commenters support the proposed rule.
Request to Allow Credit for Inspections Performed Previously
One commenter requests that the compliance time for paragraph (a)
of the proposed AD be revised to allow credit for internal visual
inspections performed previously in accordance with Task C46-53300 of
the Corrosion Prevention and Control Program (CPCP) [required by AD 92-
22-08 R1, amendment 39-8591 (58 FR 32281, June 9, 1993)]. The commenter
states that, since the primary failure mode is a cracked longeron or
shear clip, the internal visual inspection will have a crack detection
threshold lower than that of the initial external eddy current
inspection specified in paragraph (a) of the proposed AD. The FAA
concurs. The FAA finds that the structure and area specified in this AD
are identical to the structure and area being inspected in accordance
with the CPCP AD 92-22-08 R1. The FAA has determined that, for
airplanes that have been inspected previously in accordance with Task
C46-53300 of the CPCP (required by AD 92-22-08 R1) within 6,000
landings prior to the effective date of this AD, the initial HFEC
inspection required by this AD shall be accomplished within 12,000
landings. The FAA finds that a 12,000-landing compliance time
represents an appropriate interval of time allowable for these affected
airplanes to continue to operate without compromising safety. The FAA
has revised paragraph (a) of the final rule accordingly.
Conclusion
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.
Cost Impact
There are approximately 1,728 McDonnell Douglas Model DC-9 and DC-
9-80 series airplanes, Model MD-88 airplanes, and C-9 (military) series
airplanes of the affected design in the worldwide fleet. The FAA
estimates that 1,152 airplanes of U.S. registry will be affected by
this AD.
It will take approximately 17 work hours per airplane to accomplish
the required HFEC inspection, at an average labor rate of $60 per work
hour. Based on these figures, the cost impact of the HFEC inspection
required by this AD on U.S. operators is estimated to be $1,175,040, or
$1,020 per airplane, per inspection cycle.
It will take approximately 89 work hours per airplane to accomplish
the required modification, at an average labor rate of $60 per work
hour. The cost of required parts will range from $13,771 to $15,292 per
airplane. Based on these figures, the cost impact of the modification
required by this AD on U.S. operators is estimated to be between
$22,015,872 ($19,111 per airplane) and $23,768,064 ($20,632 per
airplane).
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the 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 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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
98-13-35 McDonnell Douglas: Amendment 39-10626. Docket 96-NM-203-
AD.
Applicability: Model DC-9-10, -20, -30, -40, and -50 series
airplanes; Model DC-9-81 (MD-81), -82 (MD-82), -83 (MD-83), and -87
(MD-87) series airplanes; Model MD-88 airplanes; and C-9 (military)
series airplanes; as listed in McDonnell Douglas DC-9 Service
Bulletin 53-235, dated September 15, 1993; 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.
[[Page 34587]]
Compliance: Required as indicated, unless accomplished
previously.
To prevent fatigue cracks in the skin and longerons of the
fuselage, which could result in loss of the structural integrity of
the fuselage and, consequently, lead to rapid depressurization of
the airplane, accomplish the following:
(a) Perform a high frequency eddy current (HFEC) inspection of
the external areas of the fuselage to detect cracks of the skin and/
or longeron between stations Y=160.000 and Y=218.000, in accordance
with McDonnell Douglas DC-9 Service Bulletin 53-235, dated September
15, 1993; and of the entire area between stations Y=160.000 and
Y=180.000, longeron 4 left and longeron 5 left. Perform the
inspection at the time specified in paragraph (a)(1) or (a)(2) of
this AD, as applicable.
Note 2: Where there are differences between this AD and the
referenced service bulletin, the AD prevails.
(1) For airplanes other than those identified in paragraph
(a)(2) of this AD: Inspect prior to the accumulation of 30,000 total
landings, or within 8,000 landings after the effective date of this
AD, whichever occurs later.
(2) For airplanes that have been inspected previously in
accordance with Task C46-53300 of the Corrosion Prevention and
Control Program (CPCP), as required by AD 92-22-8-R1, amendment 39-
8591, within 6,000 flight cycles prior to the effective date of this
AD: Inspect within 12,000 landings after the effective date of this
AD.
(b) Condition 1 (No Cracks). If no crack is detected during any
inspection required by this AD, accomplish either paragraph (b)(1)
or (b)(2) of this AD, in accordance with McDonnell Douglas DC-9
Service Bulletin 53-235, dated September 15, 1993.
(1) Condition 1, Option I (Repetitive Inspection). Repeat the
HFEC inspection required by paragraph (a) of this AD, and the aided
visual inspection specified in paragraph 2.E. of the Accomplishment
Instructions of the service bulletin, at intervals not to exceed
10,000 landings.
(2) Condition 1, Option II (Terminating Action Modification).
Accomplish the preventative modification installation of clips and
doublers between stations Y=160.000 and Y=218.000, in accordance
with the service bulletin. Accomplishment of the modification
constitutes terminating action for the repetitive inspection
requirements of this AD.
(c) Condition 2 (Skin Cracks). If any skin crack is detected
during any inspection required by this AD, prior to further flight,
repair it in accordance with McDonnell Douglas DC-9 Service Bulletin
53-235, dated September 15, 1993. After repair, accomplish either
paragraph (b)(1) or (b)(2) of this AD.
(d) Condition 3 (Longeron Cracks). If any longeron crack is
detected during any inspection required by this AD, prior to further
flight, repair it in accordance with McDonnell Douglas DC-9 Service
Bulletin 53-235, dated September 15, 1993. After repair, accomplish
either paragraph (b)(1) or (b)(2) of this AD.
(e) Prior to the accumulation of 100,000 total landings, or
within 4 years after the effective date of this AD, whichever occurs
later, accomplish the preventative modification specified in
paragraph 2.J. of the Accomplishment Instructions of McDonnell
Douglas DC-9 Service Bulletin 53-235, dated September 15, 1993.
Accomplishment of the modification constitutes terminating action
for the requirements of this AD.
(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 3: 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) The actions shall be done in accordance with McDonnell
Douglas DC-9 Service Bulletin 53-235, dated September 15, 1993. 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, Transport Airplane Directorate, 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 July 30, 1998.
Issued in Renton, Washington, on June 17, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-16695 Filed 6-24-98; 8:45 am]
BILLING CODE 4910-13-U
