[Federal Register Volume 63, Number 218 (Thursday, November 12, 1998)]
[Rules and Regulations]
[Pages 63134-63137]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-30049]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-99-AD; Amendment 39-10877; AD 98-23-11]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-31 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-9-31 series airplanes, 
that requires a one-time visual inspection to determine if all corners 
of the forward service door doorjamb have been modified previously, 
various follow-on repetitive inspections, and modification, if 
necessary. This amendment is prompted by reports of fatigue cracks 
found in the fuselage skin and doubler at the corners of the forward 
service door 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 December 17, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 17, 1998.

ADDRESSES: The service information referenced in this AD may be 
obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard, 
Long Beach, California 90846, Attention: Technical Publications 
Business Administration, Department 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: 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-9-31 series airplanes was published in the Federal Register on 
January 27, 1998 (63 FR 3852). That action proposed to require a one-
time visual inspection to determine if all corners of the forward 
service door doorjamb have been modified previously, 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.

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

    One commenter requests that the FAA revise the proposed AD to 
permit repairs of cracked structure to be accomplished in accordance 
with the DER of The Boeing Company, Douglas Products Division, on a 
temporary basis, rather than in accordance with 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 accomplished 
in accordance with the DC-9 Structural Repair Manual (SRM) or Service 
Rework Drawing.
    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, Douglas Products 
Division, 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.

[[Page 63135]]

Request To Revise Paragraph (e) of the Proposed AD

    One commenter requests that paragraph (e) of the proposed AD be 
revised to read as follows:
    ``(e) If the visual inspection required by paragraph (a) of this AD 
reveals that the corners of the forward doorjamb of the service door 
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.
    (e)(i) If no cracks are detected, within (6) months after the 
initial LFEC inspection, accomplish a repair approved by the Manager, 
Los Angeles ACO.
    (e)(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 (e) of the proposed 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 for 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 (e) of the AD. The FAA, in conjunction with McDonnell 
Douglas, has conducted further analysis of this issue. The FAA has 
determined that, for doorjambs of the forward service door that are 
found to be modified previously, but not in accordance with the DC-9 
SRM, an initial low frequency eddy current inspection of the fuselage 
skin adjacent to those existing repairs will not detect any cracking 
under the repairs. In light of this determination, no change to this 
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 
proposed AD. The commenter states that such a revision will eliminate 
confusion between the DC-9 SID and the proposed 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 Revise Compliance Time for Low Frequency Eddy Current 
(LFEC) or X-ray Inspection

    One commenter requests that the compliance time for the initial 
inspection (LFEC or x-ray) in paragraph (b) of the proposal be revised 
to correspond with those presently in the SID program--within three 
years after the effective date of the AD, or prior to 53,140 landings, 
whichever occurs later. The commenter points out that such a revision 
would permit its fleet to be inspected during major scheduled 
maintenance checks, which would reduce the burden of line maintenance 
and the number of line airplanes out of service as a result of any 
findings. The commenter agrees that the repetitive inspection interval 
should remain at 3,225 landings, as specified in the proposed rule.
    The FAA does not concur with the commenter's request to revise the 
compliance time for the initial inspection specified in paragraph (b) 
of the AD. The commenter provided no technical justification for 
revising this interval. Fatigue cracking of the fuselage skin and 
doubler at the corners of the forward service door doorjamb is a 
significant safety issue, and the FAA has determined that the 
inspection threshold, as proposed, is warranted, based on the 
effectiveness of the inspection procedure to detect fatigue cracking. 
The FAA considered not only those safety issues in developing an 
appropriate compliance time for this action, but the recommendations of 
the manufacturer, and the practical aspect of accomplishing the 
required inspection within an interval of time that parallels normal 
scheduled maintenance for the majority of affected operators. In light 
of these factors, the FAA has determined that the initial compliance 
time, as proposed, is appropriate.

Other Relevant Rulemaking

    The FAA has revised the final rule to include a new paragraph (f). 
This new paragraph states that accomplishment of the inspection 
requirements of this AD constitutes terminating action for inspections 
of Principal Structural Element (PSE) 53.09.033 (reference McDonnell 
Douglas Model DC-9 Supplemental Inspection Document) required by AD 96-
13-03, amendment 39-9671 (61 FR 31009, June 19, 1996). Since this new 
paragraph is being added, the FAA has removed ``NOTE 4,'' which is no 
longer necessary.

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 change previously 
described. The FAA has determined that this change will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 64 McDonnell Douglas Model DC-9-31 series 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 51 airplanes of U.S. registry will be affected by this 
AD, that it will take approximately 1 work hour per airplane to 
accomplish the required one-time visual inspection, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the one-time visual inspection required by this AD on 
U.S. operators is estimated to be $3,060, or $60 per airplane.
    The cost impact figure discussed above is 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 LFEC or x-ray 
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 any necessary LFEC or x-ray 
inspection is estimated to be $60 per airplane, per inspection cycle.
    Should an operator be required to accomplish the HFEC 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 any necessary HFEC inspection is estimated to be $60 per 
airplane, per inspection cycle.
    Should an operator be required to accomplish the modification, it 
would take approximately 30 work hours per airplane to accomplish, at 
an average labor rate of $60 per work hour. Required parts would cost 
approximately $4,800 per airplane. Based on these figures, the cost 
impact of any necessary modification is estimated to be $6,600 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

[[Page 63136]]

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:

98-23-11  McDonnell Douglas: Amendment 39-10877. Docket 97-NM-99-AD.

    Applicability: Model DC-9-31 series airplanes, as listed in 
McDonnell Douglas Service Bulletin DC9-53-288, dated February 10, 
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 (g) 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 service door 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: The words ``repair'' and ``modify/modification'' in this 
AD and the referenced service bulletin are used interchangeably.

    (a) Prior to the accumulation of 50,000 total landings, or 
within 3,225 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 service door doorjamb have been modified. 
Perform the inspection in accordance with McDonnell Douglas Service 
Bulletin DC9-53-288, dated February 10, 1997.
    (b) For airplanes identified as Group 1 in McDonnell Douglas 
Service Bulletin DC9-53-288, dated February 10, 1997: If the visual 
inspection required by paragraph (a) of this AD reveals that the 
corners of the forward service door 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 service door doorjamb, in 
accordance with McDonnell Douglas Service Bulletin DC9-53-288, dated 
February 10, 1997.
    (1) Group 1, Condition 1. If no crack is detected during any 
LFEC or x-ray inspection required by paragraph (b) of this AD, 
accomplish the requirements of either paragraph (b)(1)(i) or 
(b)(1)(ii) of this AD, in accordance with the service bulletin.
    (i) Option 1. Repeat the LFEC inspection required by this 
paragraph thereafter at intervals not to exceed 3,225 landings, or 
the x-ray inspection required by this paragraph thereafter at 
intervals not to exceed 3,075 landings; or
    (ii) Option 2. Prior to further flight, modify the corner skin 
of the forward service door doorjamb in accordance with the service 
bulletin. Prior to the accumulation of 28,000 landings after 
accomplishment of the modification, perform a high frequency eddy 
current (HFEC) inspection to detect cracks on the skin adjacent to 
the modification, in accordance with the service bulletin.
    (A) If no crack is detected on the skin adjacent to the 
modification during the HFEC required by this paragraph, 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 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) Group 1, Condition 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/repair the corners of the doorjamb of the forward service 
door in accordance with the service bulletin. Prior to the 
accumulation of 28,000 landings after accomplishment of the 
modification, perform a 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 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.
    (3) Group 1, Condition 3. If any crack is found during any LFEC 
or x-ray inspection required by paragraph (b) of this AD, 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) Group 2, Condition 1. For airplanes identified as Group 2 in 
McDonnell Douglas Service Bulletin DC9-53-288, dated February 10, 
1997: If the visual inspection required by paragraph (a) of this AD 
reveals that the corners of the forward service door doorjamb have 
been modified previously in accordance with the McDonnell Douglas 
DC-9 Structural Repair Manual, using a steel doubler, accomplish 
either paragraph (c)(1) or (c)(2) of this AD in accordance with 
McDonnell Douglas Service Bulletin DC9-53-288, dated February 10, 
1997.
    (1) Option 1. Prior to the accumulation of 6,000 landings after 
accomplishment of that modification, or within 3,225 landings after 
the effective date of this AD, whichever occurs later, 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 paragraph (c)(1) of this AD, repeat the HFEC inspection 
thereafter at intervals not to exceed 3,000 landings.
    (ii) If any crack is detected during any HFEC inspection 
required by paragraph (c)(1) of this AD, prior to further flight, 
repair it in accordance with a method approved by the Manager, Los 
Angeles ACO.
    (2) Option 2. Prior to further flight, modify the corner skin of 
the forward service door doorjamb in accordance with the service 
bulletin. 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 on the skin adjacent to the 
modification during the HFEC required by this paragraph, repeat the 
HFEC inspection thereafter at intervals not to exceed 20,000 
landings.
    (ii) If any crack is detected on the skin adjacent to the 
modification 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.

[[Page 63137]]

    (d) Group 2, Condition 2. For airplanes identified as Group 2 in 
McDonnell Douglas Service Bulletin DC9-53-288, dated February 10, 
1997: If the visual inspection required by paragraph (a) of this AD 
reveals that the corners of the forward service door doorjamb have 
been modified previously in accordance with McDonnell Douglas DC-9 
Structural Repair Manual, using an aluminum doubler, prior to the 
accumulation of 28,000 landings after accomplishment of that 
modification, or within 3,225 landings after the effective date of 
this AD, whichever occurs later, perform an HFEC inspection to 
detect cracks on the skin adjacent to the modification, in 
accordance with McDonnell Douglas Service Bulletin DC9-53-288, dated 
February 10, 1997.
    (1) If no crack is detected on the skin adjacent to the 
modification during the HFEC required by this paragraph, repeat the 
HFEC inspection thereafter at intervals not to exceed 20,000 
landings.
    (2) If any crack is detected on the skin adjacent to the 
modification 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) Group 2, Condition 3. For airplanes identified as Group 2 in 
McDonnell Douglas Service Bulletin DC9-53-288, dated February 10, 
1997: If the visual inspection required by paragraph (a) of this AD 
reveals that the corners of the forward service door doorjamb have 
been modified previously, but not in accordance with McDonnell 
Douglas Structural Repair Manual, prior to further flight, repair 
the corners in accordance with a method approved by the Manager, Los 
Angeles ACO.
    (f) 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) required by AD 96-13-
03, amendment 39-9671.
    (g) 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 ACO. 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.

    (h) 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.
    (i) Except as provided by paragraphs (b)(1)(ii)(B), (b)(2)(ii), 
(b)(3), (c)(1)(ii), (c)(2)(ii), (d)(2), and (e) of this AD, the 
actions shall be done in accordance with McDonnell Douglas Service 
Bulletin DC9-53-288, dated February 10, 1997. 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 McDonnell Douglas Corporation, 3855 Lakewood 
Boulevard, Long Beach, California 90846, Attention: Technical 
Publications Business Administration, Department 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.
    (j) This amendment becomes effective on December 17, 1998.

    Issued in Renton, Washington, on November 3, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-30049 Filed 11-10-98; 8:45 am]
BILLING CODE 4910-13-U