[Federal Register Volume 64, Number 134 (Wednesday, July 14, 1999)]
[Rules and Regulations]
[Pages 37838-37841]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-17858]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-49-AD; Amendment 39-11224; AD 99-15-05]
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 aft 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 aft 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 aft 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

[[Page 37839]]

consequent reduced structural integrity of the airplane.

DATES: Effective August 18, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 18, 1999.

ADDRESSES: The service information referenced in this AD may be 
obtained from The Boeing Company, Douglas Products Division, P.O. Box 
1771, Long Beach, California 90846-1771, Attention: Business Unit 
Manager, Contract Data Management, C1-255 (35-22). This information may 
be examined at the Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington; 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: 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 August 11, 1997 (62 
FR 42949). That action proposed to require a one-time visual inspection 
to determine if all corners of the aft lower cargo doorjamb have been 
previously modified. That action also proposed to require low frequency 
eddy current inspections to detect cracks of the fuselage skin and 
doubler at all corners of the aft lower cargo doorjamb, various follow-
on repetitive inspections, and modification, if necessary.

New Service Information

    Since the issuance of the NPRM, McDonnell Douglas has issued 
Service Bulletin DC9-53-278, Revision 01, dated April 29, 1999. That 
service bulletin removes reference to a low frequency eddy current 
inspection after doubler installation and changes the inspection to a 
high frequency eddy current inspection. Other administrative changes 
were also included in the revised service bulletin.

Consideration of 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.

Support for the Proposal

    One commenter supports the proposal.

Request To Allow Designated Engineering Representative (DER) 
Approval of Certain Repairs

    One commenter requests that, rather than require approval of 
Manager of the Los Angeles Aircraft Certification Office (ACO) for 
certain repairs [cracking conditions beyond the allowable repair limits 
specified in the proposal, and for existing repairs that are not 
accomplished in accordance with the DC-9 Structural Repair Manual (SRM) 
or Service Rework Drawings], a Boeing/Douglas Aircraft Division 
Designated Engineering Representative (DER) be designated with the 
authority to approve such repairs temporarily. The commenter states 
that this would expedite the approval process yet ensure an adequate 
level of safety since the Manager of the Los Angles ACO would have 
final authority to approve the repair as a permanent repair. The 
commenter states that if the FAA does not approve the temporary repair 
as a permanent repair, it could then require any corrective action to 
be accomplished, preferably at the next scheduled major maintenance 
check.
    The FAA does not concur. While DER's are authorized to determine 
whether a design or repair method complies with a specific requirement, 
they are not currently authorized to make the discretionary 
determination as to what the applicable requirement is. However, the 
FAA has issued a notice (N 8110.72, dated March 30, 1998), which 
provides guidance for delegating authority to certain type certificate 
holder structural DER's to approve alternative methods of compliance 
for AD-required repairs and modifications of individual airplanes. The 
FAA is currently working with The Boeing Company, Long Beach Division 
(BLBD), to develop the implementation process for delegation of 
approval of alternative methods of compliance in accordance with that 
notice. Once this process is implemented, approval authority for 
alternative methods of compliance can be delegated without revising the 
AD.

Request to Revise Paragraph (c) of the 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 aft 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 (LFEC) 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 operational 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 the manufacturer, 
has conducted further analysis of this issue. The FAA has determined 
that, for cargo doorjambs that 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, as suggested by the commenter, will not detect any cracking 
under the repairs. The FAA considers that, once cracking emerges from 
under a repair, crack growth could rapidly occur. 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 detect and correct the identified 
unsafe condition. After issuance of the final rule, the manufacturer 
may revise the DC-9 SID.

[[Page 37840]]

Other Relevant Rulemaking

    The FAA has revised the final rule to include a new paragraph (e). 
This new paragraph states that accomplishment of the inspection 
requirements of this AD constitutes terminating action for inspections 
of Principal Structural Element (PSE) 53.09.035 [reference McDonnell 
Douglas Model DC-9 Supplemental Inspection Document, Report No. L26-
008, Section 2 of Volume 1, Revision 5, dated July 1997, as required by 
AD 96-13-03, amendment 39-9671 (61 FR 31009, June 19, 1996)]. Since 
this new paragraph is being added, ``NOTE 3'' of the proposal, which 
discussed the relation of this AD to AD 96-13-03 is no longer 
necessary. Therefore, the FAA has removed ``NOTE 3'' of the proposal 
and renumbered the NOTES in the final rule accordingly.

Other Changes to the Final Rule

    Based on new information received from the manufacturer, the FAA 
has revised the cost estimate for parts that would be needed if an 
operator were to find it necessary to accomplish the modification 
specified in this final rule. The Cost Impact section of the NPRM 
stated that the estimated cost for those parts would be $692 to $990 
per airplane. The revised figure for the estimated parts cost is $936 
to $2007 per airplane. The final rule has been revised 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 899 McDonnell 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.
    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.
    Should an operator be required to accomplish the eddy current 
inspections, it will 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 eddy current inspections 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 modification, it 
will take approximately 14 work hours per airplane to accomplish, at an 
average labor rate of $60 per work hour. Required parts would 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.

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:

99-15-05  McDonnell Douglas: Amendment 39-11224. Docket 97-NM-49-AD.

    Applicability: Model DC-9-10, -20, -30, -40, and -50 series 
airplanes, and C-9 (military) airplanes, as listed in McDonnell 
Douglas DC-9 Service Bulletin DC9-53-278, dated November 4, 1996, or 
McDonnell Douglas DC-9 Service Bulletin DC9-53-278, Revision 01, 
dated April 29, 1999; 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 fuselage skin or 
doubler at the corners of the aft 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.
    (a) Prior to the accumulation of 48,000 total landings, or 
within 3,575 landings after the effective date of this AD, whichever 
occurs later, perform a one-time visual inspection to determine if 
the corners of the aft 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 aft 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 aft lower cargo doorjamb, in 
accordance with McDonnell Douglas Service Bulletin DC9-53-278, dated 
November 4, 1996, or Revision 01, dated April 29, 1999.
    (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.

[[Page 37841]]

    (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 3,575 landings.
    (B) If the immediately preceding inspection was conducted using 
x-ray techniques, conduct the next inspection within 3,075 landings.
    (ii) Option 2. Prior to further flight, modify the corners of 
the aft lower cargo doorjamb, in accordance with either service 
bulletin. Prior to the accumulation of 28,000 landings after 
accomplishment of that modification, perform a High Frequency Eddy 
Current (HFEC) inspection to detect cracks on the skin adjacent to 
the modification, in accordance with McDonnell Douglas Service 
Bulletin DC9-53-278, Revision 01, dated April 29, 1999. Repeat the 
HFEC 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 HFEC or x-ray inspection required by 
paragraph (b) of this AD, repeat the HFEC 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 HFEC 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 paragraph (b) of this AD and the crack is 2 inches or 
less in length: Prior to further flight, modify it in accordance 
with McDonnell Douglas Service Bulletin DC9-53-278, Revision 01, 
dated April 29, 1999. Prior to the accumulation of 28,000 landings 
after accomplishment of the modification, perform an HFEC 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 HFEC inspection required 
by this paragraph, repeat the HFEC inspection thereafter at 
intervals not to exceed 20,000 landings.
    (ii) If any crack is detected during the HFEC 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 aft 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 aft 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 HFEC inspection to 
detect cracks on the skin adjacent to the modification, in 
accordance with McDonnell Douglas Service Bulletin DC9-53-278, 
Revision 01, dated April 29, 1999. Repeat the HFEC inspection 
thereafter at intervals not to exceed 20,000 landings.
    (1) If no crack is detected during any HFEC inspection required 
by this paragraph, repeat the HFEC inspection thereafter at 
intervals not to exceed 20,000 landings.
    (2) If any crack is detected during any HFEC inspection required 
by this paragraph, prior to further flight, repair it in accordance 
with a method approved by the Manager, Los Angeles ACO.
    (e) Accomplishment of the actions required by this AD 
constitutes terminating action for inspections of Principal 
Structural Element (PSE) 53.09.033 (reference McDonnell Douglas 
Model DC-9 Supplemental Inspection Document, Report No. L26-008, 
Section 2 of Volume 1, Revision 5, dated July 1997, as required by 
AD 96-13-03, amendment 39-9671).
    (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) Except as provided in paragraphs (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 DC9-53-278, dated 
November 4, 1996, and McDonnell Douglas Service Bulletin DC9-53-278, 
Revision 01, dated April 29, 1999. 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, P.O. Box 1771, Long 
Beach, California 90846-1771, Attention: Business Unit Manager, 
Contract Data Management, C1-255 (35-22). Copies may be inspected at 
the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., 
Renton, Washington; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.
    (i) This amendment becomes effective on August 18, 1999.

    Issued in Renton, Washington, on July 7, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-17858 Filed 7-13-99; 8:45 am]
BILLING CODE 4910-13-U