[Federal Register Volume 63, Number 74 (Friday, April 17, 1998)]
[Rules and Regulations]
[Pages 19180-19182]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-10056]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-40-AD; Amendment 39-10473; AD 98-08-24]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, -
30, -40, and -50 Series Airplanes, and C-9 (Military) 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-9-10, -20, -30, -40, 
and -50 series airplanes, and C-9 (military) airplanes, that requires a 
one-time visual inspection to determine if all corners of the forward 
lower cargo doorjamb have been previously modified. This amendment also 
requires low frequency eddy current inspections to detect cracks of the 
fuselage skin and doubler at all corners of the forward lower cargo 
doorjamb, various follow-on repetitive inspections, and modification, 
if necessary. This amendment is prompted by fatigue cracks found in the 
fuselage skin and doubler at the corners of the forward lower cargo 
doorjamb. The actions specified by 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 May 22, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 22, 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, 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: 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: 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-9-10, -20, -30, -40, and -50 series airplanes, and C-9 (military) 
airplanes was published in the Federal Register on July 25, 1997 (62 FR 
39975). That action proposed to require a one-time visual inspection to 
determine if all corners of the forward lower cargo doorjamb have been 
modified previously. That action also proposed to require low frequency 
eddy current (LFEC) inspections to detect cracks of the fuselage skin 
and doubler at all corners of the forward lower cargo doorjamb, various 
follow-on repetitive inspections, and modification, if necessary.
    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 proposed AD.

Permit Repairs in Accordance With Designated Engineering 
Representative (DER) Approval

    One commenter requests that proposed paragraphs (b)(3) and (c) be 
revised to permit the repair of cracked structure to be accomplished in 
accordance with the DER of The Boeing Company, Douglas Products 
Division for a temporary basis, rather than the Manager of the Los 
Angeles Aircraft Certification Office (ACO). The commenter states that 
such an approval would expedite the process for repair approval for a 
crack condition beyond the allowable repair limits (i.e., greater than 
2 inches in length) and for existing repairs that are not in accordance 
with the DC-9 Structural Repair Manual (SRM) or Service Rework Drawing.
    The FAA does not concur that revision of the AD is necessary. The 
FAA is currently in the process of implementing procedures by which AD-
mandated structural repairs may be approved by certain DER's employed 
by

[[Page 19181]]

type certificate holders. Once the procedures are implemented, these 
DER's will be authorized to issue such approvals, and no change to the 
AD is necessary to allow for this.

Request To Revise Requirements of Proposed AD

    One commenter requests that paragraph (c) of the proposed AD be 
revised to read as follows:
    ``(c) If the visual inspection required by paragraph (a) of this AD 
reveals that the corners of the forward lower cargo doorjamb have been 
modified by FAA approved repairs other than the DC-9 SRM or Service 
Rework Drawing, prior to further flight, accomplish an initial Low 
Frequency Eddy Current inspection of the fuselage skin adjacent to the 
repair.
    (c)(i) If no cracks are detected, within (6) months after the 
initial LFEC inspection, accomplish a repair approved by the Manager, 
Los Angeles ACO.
    (c)(ii) If cracks are detected, prior to further flight, repair in 
accordance with a method approved by the Manager, Los Angeles ACO.''
    This commenter states that, as paragraph (c) of the AD is currently 
worded, it will cause an unnecessary operation impact since FAA-
approved non-standard SRM or Service Rework Drawing repairs are known 
to exist in this area of the doorjamb. The commenter contends that 
obtaining approval for such repairs from the Los Angeles ACO, prior to 
further flight, will be time consuming and will result in an 
unwarranted extended ground time for the airplane.
    The FAA does not concur with the commenter's request to revise 
paragraph (c) of the AD. The FAA in conjunction with McDonnell Douglas 
has conducted further analysis of this issue. The FAA has determined 
that, for cargo doorjambs which are found to be modified previously but 
not in accordance with the DC-9 SRM or Service Rework Drawing, an 
initial LFEC inspection of the fuselage skin adjacent to those existing 
repairs will not detect any cracking under the repairs. In light of 
these findings, no change to the final rule is necessary.

Request To Revise DC-9 Supplemental Inspection Document (SID)

    One commenter requests that, prior to issuance of the final rule, 
the DC-9 SID be revised to incorporate the actions required by this AD. 
The commenter states that such a revision will eliminate confusion 
between the DC-9 SID and the AD. The FAA does not concur. The actions 
required by this AD are necessary to ensure inspection continuity for 
the affected Principal Structural Element (PSE). After issuance of the 
final rule, the manufacturer may revise the DC-9 SID.

Request to Develop Standard Repairs

    One commenter request that, for previously repaired corners and for 
cracks greater than 2 inches long, McDonnell Douglas develop additional 
``standard repairs'' that are pre-approved by the Manager, Los Angeles 
ACO, FAA, Transport Airplane Directorate. The commenter contends that 
the cargo door area is one of the most easily damaged areas on the 
airplane and that there are many non-SRM or Service Rework Drawing 
repairs that exist in this area. The commenter states that such an 
approval would minimize the amount of time required to obtain the 
approved repair and the impact to flight and maintenance schedules.
    The FAA does not concur with the commenter's request to pre-approve 
``standard repairs.'' The manufacturer has indicated that it has not 
received many requests for approval of repairs required by paragraph 
(b)(3) or (c) of this AD. Therefore, a repair approved by the Manager 
of the Los Angeles ACO will be developed on a case-by-case basis. In 
addition, the Manager and staff of the Los Angeles ACO are working very 
closely with the manufacturer to expedite repair approval requests. 
Such requests may be made under the provisions of paragraph (e) of the 
final rule.

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 as proposed.

Cost Impact

    There are approximately 899 McDonnell Douglas Model DC-9-10, -20, -
30, -40, and -50 series airplanes, and C-9 (military) airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 622 
airplanes of U.S. registry will be affected by this AD.
    It will take approximately 1 work hour per airplane to accomplish 
the required visual inspection, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the visual 
inspection required by this AD on U.S. operators is estimated to be 
$37,320, or $60 per airplane.
    Should an operator be required to accomplish the LFEC inspection, 
it would take approximately 1 work hour per airplane to accomplish, at 
an average labor rate of $60 per work hour. Based on these figures, the 
cost impact of the LFEC inspection required by this AD on U.S. 
operators is estimated to be $60 per airplane.
    Should an operator be required to accomplish the modification, it 
would take approximately 14 work hours per airplane to accomplish, at 
an average labor rate of $60 per work hour. Required parts will cost 
approximately $936, or $2,807 per airplane, depending on the service 
kit purchased. Based on these figures, the cost impact of the 
modification required by this AD on U.S. operators is estimated to be 
$1,776 or $3,647 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:

[[Page 19182]]

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:

98-08-24  McDonnell Douglas: Amendment 39-10473. Docket 97-NM-40-AD.

    Applicability: Model DC-9-10, -20, -30, -40, and -50 series 
airplanes, and C-9 (military) airplanes, as listed in McDonnell 
Douglas Service Bulletin DC9-53-277, dated September 30, 1996; 
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 (e) 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 fuselage skin or 
doubler at the corners of the forward lower cargo doorjamb, 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 service bulletin 
and the AD, the AD prevails.
    Note 3: This AD is related to AD 96-13-03, amendment 39-9671, 
(61 FR 31009, June 19, 1996), and will affect Principal Structural 
Element (PSE) 53.09.001 of the DC-9 Supplemental Inspection Document 
(SID).

    (a) Prior to the accumulation of 48,000 total landings, or 
within 3,500 landings after the effective date of this AD, whichever 
occurs later, perform a one-time visual inspection to determine if 
the corners of the forward lower cargo doorjamb have been modified 
prior to the effective date of this AD.
    (b) If the visual inspection required by paragraph (a) of this 
AD reveals that the corners of the forward lower cargo doorjamb have 
not been modified, prior to further flight, perform a low frequency 
eddy current (LFEC) or x-ray inspection to detect cracks of the 
fuselage skin and doubler at all corners of the forward lower cargo 
doorjamb, in accordance with McDonnell Douglas Service Bulletin DC9-
53-277, dated September 30, 1996.
    (1) If no crack is detected during the LFEC or x-ray inspection 
required by this paragraph, accomplish the requirements of either 
paragraph (b)(1)(i) or (b)(1)(ii) of this AD.
    (i) Option 1. Repeat the inspections as follows until paragraph 
(b)(1)(ii) of this AD is accomplished:
    (A) If the immediately preceding inspection was conducted using 
LFEC techniques, conduct the next inspection within 3,500 landings.
    (B) If the immediately preceding inspection was conducted using 
x-ray techniques, conduct the next inspection within 2,850 landings.
    (ii) Option 2. Prior to further flight, modify the corners of 
the forward lower cargo doorjamb, in accordance with the service 
bulletin. Prior to the accumulation of 28,000 landings after 
accomplishment of that modification, perform a LFEC inspection to 
detect cracks on the skin adjacent to the modification, in 
accordance with the service bulletin. Repeat the LFEC inspection 
thereafter at intervals not to exceed 20,000 landings.
    (A) If no crack is detected on the skin adjacent to the 
modification during any LFEC or x-ray inspection required by this 
paragraph, repeat the LFEC inspection thereafter at intervals not to 
exceed 20,000 landings.
    (B) If any crack is detected on the skin adjacent to the 
modification during any LFEC or x-ray inspection required by this 
paragraph, prior to further flight, repair it in accordance with a 
method approved by the Manager, Los Angeles Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate.
    (2) If any crack is found during any LFEC or x-ray inspection 
required by this paragraph and the crack is 2 inches or less in 
length: Prior to further flight, modify it in accordance with the 
service bulletin. Prior to the accumulation of 28,000 landings after 
accomplishment of the modification, perform a LFEC inspection to 
detect cracks on the skin adjacent to the modification, in 
accordance with the service bulletin.
    (i) If no crack is detected during the LFEC inspection required 
by this paragraph, repeat the LFEC inspection thereafter at 
intervals not to exceed 20,000 landings.
    (ii) If any crack is detected during the LFEC inspection 
required by this paragraph, prior to further flight, repair it in 
accordance with a method approved by the Manager, Los Angeles ACO.
    (3) If any crack is found during any LFEC or x-ray inspection 
required by this paragraph and the crack is greater than 2 inches in 
length: Prior to further flight, repair it in accordance with a 
method approved by the Manager, Los Angeles ACO.
    (c) If the visual inspection required by paragraph (a) of this 
AD reveals that the corners of the forward lower cargo doorjamb have 
been modified, but not in accordance with the DC-9 Structural Repair 
Manual (SRM) or Service Rework Drawing, prior to further flight, 
repair it in accordance with a method approved by the Manager, Los 
Angeles ACO.
    (d) If the visual inspection required by paragraph (a) of this 
AD reveals that the corners of the forward lower cargo doorjamb have 
been modified in accordance with DC-9 SRM or Service Rework Drawing, 
prior to the accumulation of 28,000 landings since accomplishment of 
that modification, or within 3,500 landings after the effective date 
of this AD, whichever occurs later, perform a LFEC inspection to 
detect cracks on the skin adjacent to the modification, in 
accordance with McDonnell Douglas Service Bulletin DC9-53-277, dated 
September 30, 1996. Repeat the LFEC inspection thereafter at 
intervals not to exceed 20,000 landings.
    (1) If no crack is detected during any LFEC inspection required 
by this paragraph, repeat the LFEC inspection thereafter at 
intervals not to exceed 20,000 landings.
    (2) If any crack is detected during any LFEC inspection required 
by this paragraph, prior to further flight, repair it in accordance 
with a method approved by the Manager, Los Angeles ACO.
    (e) 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.

    (f) 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.
    (g) Except as provided by paragraphs (a), (b)(1)(ii)(B), 
(b)(2)(ii), (b)(3), (c), and (d)(2) of this AD, the actions shall be 
done in accordance with McDonnell Douglas Service Bulletin DC9-53-
277, dated September 30, 1996. 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 FAA, 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.
    (h) This amendment becomes effective on May 22, 1998.

    Issued in Renton, Washington, on April 9, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-10056 Filed 4-16-98; 8:45 am]
BILLING CODE 4910-13-U