AD Amdt-39-10948

[Federal Register Volume 63, Number 245 (Tuesday, December 22, 1998)]
[Rules and Regulations]
[Pages 70633-70636]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-33388]



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Federal Register / Vol. 63, No. 245 / Tuesday, December 22, 1998 / 
Rules and Regulations

[[Page 70633]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-56-AD; Amendment 39-10948; AD 98-26-08]
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 doorjamb 
of the forward service door have been previously modified. The action 
also requires various repetitive inspections to detect cracks of the 
fuselage skin and doubler at all corners of the doorjamb of the forward 
service door, and to detect cracks on the skin adjacent to the 
modification; and various follow-on actions. This amendment is prompted 
by reports of fatigue cracks found in the fuselage skin and doubler at 
the corners of the doorjamb of the forward service door. 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 January 26, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 26, 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; 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-9-10, -20, -30, -40, and -50 series airplanes, and C-9 (military) 
airplanes, was published in the Federal Register on August 12, 1997 (62 
FR 43128). That action proposed to require a one-time visual inspection 
to determine if all corners of the doorjamb of the forward service door 
have been previously modified. The action also proposed to require 
various repetitive inspections to detect cracks of the fuselage skin 
and doubler at all corners of the doorjamb of the forward service door, 
and to detect cracks on the skin adjacent to the modification; and 
various follow-on actions.
    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 proposed AD be revised to allow 
approval of repairs not addressed in the cited service bulletins by a 
McDonnell Douglas designated engineering representative (DER), instead 
of the Manager of the Los Angeles Aircraft Certification Office (ACO). 
The commenter states that this provision would result in a more 
efficient and expeditious repair approval process.
    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), that 
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 Boeing, 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 Requirements of 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 service door doorjamb 
have been modified by FAA-approved repairs other than those 
specified by the DC-9 Structural Repair Manual (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.
    (e)(i) If no crack is detected, within (6) months after the 
initial LFEC inspection, repair in accordance with a method approved 
by the Manager, Los Angeles ACO.
    (e)(ii) If any crack is 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 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

[[Page 70634]]

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 forward service door 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 will not detect any cracking under the repairs. 
Because cracking under the repairs could grow rapidly once it emerges 
from under the repairs, the FAA does not consider that an acceptable 
level of safety can be assured simply by determining that cracking has 
not yet emerged from under the repairs. In light of these findings, no 
change to the final rule is necessary.

Request To Increase Repetitive Inspection Interval

    One commenter requests that the repetitive inspection interval 
specified by paragraph (b)(1)(i)(A) of the proposed AD be increased 
from 3,225 landings to 3,575 landings. The commenter states that such 
an increase of the inspection interval would allow affected airplanes 
to be inspected during major scheduled maintenance checks, and would 
reduce the number of line airplanes that would be taken out of service 
as a result of any findings during the inspection.
    The FAA does not concur that the repetitive inspection interval 
should be increased. The operator provided no technical justification 
for revising the repetitive inspection interval as requested. Fatigue 
cracking of the fuselage skin and doubler at the corners of the 
doorjamb of the forward service door is an identified safety issue, and 
the FAA has determined that the repetitive inspection interval, as 
proposed, is warranted, based on the effectiveness of the inspection 
procedure to detect cracking. The FAA considered not only those safety 
issues in developing an appropriate repetitive inspection interval 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 inspection interval of 3,225 landings, as proposed, 
is appropriate.

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.

Explanation of Changes Made to the Final Rule

    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.
    The FAA notes that an editorial change is necessary to clarify the 
intent of paragraph (b) of the proposed rule. The first sentence in 
that paragraph refers to the corners of the ``upper cargo doorjamb.'' 
The intent of that sentence is to determine if the visual inspection 
reveals that the corners of the doorjamb of the forward service door 
have not been modified, not the ``upper cargo doorjamb.'' The FAA has 
revised the final rule to specify this clarification.

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 823 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 575 
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 
$34,500, or $60 per airplane.
    Should an operator be required to accomplish the HFEC, LFEC, or x-
ray inspection, 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 inspection required by this AD on 
U.S. operators is estimated to be $60 per airplane, per inspection 
cycle.
    Should an operator be required to accomplish the modification, it 
will take approximately 30 work hours per airplane to accomplish, at an 
average labor rate of $60 per work hour. Required parts will cost 
approximately $1,256, $1,420, $5,804, or $6,113 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 $3,056, $3,220, $7,604, or $7,913 per airplane, respectively.
    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.

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.

[[Page 70635]]

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:

98-26-08  MCDONNELL DOUGLAS: Amendment 39-10948. Docket 97-NM-56-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 DC9-53-279, Revision 01, dated May 6, 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 doorjamb of the forward service door, 
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 doorjamb of the forward service door have been 
modified prior to the effective date of this AD.
    (b) Group 1. If the visual inspection required by paragraph (a) 
of this AD reveals that the corners of the doorjamb of the forward 
service door 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 
doorjamb of the forward service door, in accordance with McDonnell 
Douglas Service Bulletin DC9-53-279, dated December 10, 1996, or 
Revision 01, dated May 6, 1996.
    (1) Condition 1. If no crack is detected during any inspection 
required by paragraph (b) of this AD, accomplish 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 3,225 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 doorjamb of the forward service door in accordance with the 
service bulletin; this modification constitutes terminating action 
for the repetitive inspection requirements of paragraph (b)(1)(i) of 
this AD. 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. Within 
20,000 landings after accomplishment of the HFEC inspection, perform 
an eddy current inspection to detect cracks in the subject area, in 
accordance with the service bulletin.
    (A) If no crack is detected on the skin adjacent to the 
modification during any eddy current inspection required by 
paragraph (b)(1)(ii) of this AD, repeat the eddy current 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 eddy current inspection required by 
paragraph (b)(1)(ii) of this AD, repair it in accordance with a 
method approved by the Manager, Los Angeles ACO.
    (2) Condition 2. If any crack is found during any 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 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. Within 20,000 
landings after accomplishment of the HFEC inspection, perform an 
eddy current inspection to detect cracks in the subject area, in 
accordance with the service bulletin.
    (i) If no crack is detected on the skin adjacent to the 
modification during any eddy current inspection required by 
paragraph (b)(2) of this AD, repeat the eddy current 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 eddy current inspection required by 
paragraph (b)(2) of this AD, repair it in accordance with a method 
approved by the Manager, Los Angeles ACO.
    (3) Condition 3. If any crack is found during any 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) Group 2, Condition 1. If the visual inspection required by 
paragraph (a) of this AD reveals that the corners of the doorjamb of 
the forward service door have been modified in accordance with the 
DC-9 Structural Repair Manual (SRM) (using a steel doubler), 
accomplish either paragraph (c)(1) or (c)(2) of this AD in 
accordance with McDonnell Douglas Service Bulletin DC9-53-279, dated 
December 10, 1996, or Revision 01, dated May 6, 1997.
    (1) Option 1. Prior to the accumulation of 6,000 landings after 
the effective date of this AD, perform a HFEC inspection to detect 
cracks on the skin adjacent to the modification in accordance with 
the service bulletin. Within 3,000 landings after accomplishment of 
the HFEC inspection, perform an eddy current inspection to detect 
cracks in the subject area, in accordance with the service bulletin.
    (i) If no crack is detected on the skin adjacent to the 
modification during any eddy current inspection required by 
paragraph (c)(1) of this AD, repeat the eddy current inspection 
thereafter at intervals not to exceed 3,000 landings.
    (ii) If any crack is detected on the skin adjacent to the 
modification during any eddy current inspection required by 
paragraph (c)(1) of this AD, repair it in accordance with a method 
approved by the Manager, Los Angeles ACO.
    (2) Option 2. Prior to further flight, modify 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. Within 20,000 landings after 
accomplishment of the HFEC inspection, perform an eddy current 
inspection to detect cracks in the subject area, in accordance with 
the service bulletin.
    (i) If no crack is detected on the skin adjacent to the 
modification during any eddy current inspection required by 
paragraph (c)(2) of this AD, repeat the eddy current 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 eddy current inspection required by 
paragraph (c)(2) of this AD, repair it in accordance with a method 
approved by the Manager, Los Angeles ACO.
    (d) Group 2, Condition 2. If the visual inspection required by 
paragraph (a) of this AD reveals that the corners of the doorjamb of 
the forward service door have been modified in accordance with DC-9 
SRM or Service Rework Drawing (using an aluminum doubler), prior to 
the accumulation of 28,000 landings since accomplishment of the 
modification, or within 3,225 landings after the effective date of 
this AD, whichever occurs later, perform a HFEC inspection to detect 
cracks on the skin adjacent to the

[[Page 70636]]

modification, in accordance with McDonnell Douglas Service Bulletin 
DC9-53-279, dated December 10, 1996, or Revision 01, dated May 6, 
1997. Within 20,000 landings after accomplishment of the HFEC 
inspection, perform an eddy current inspection to detect cracks in 
the subject area, in accordance with the service bulletin.
    (1) If no crack is detected on the skin adjacent to the 
modification during any eddy current inspection required by 
paragraph (d) of this AD, repeat the eddy current 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 eddy current inspection required by 
paragraph (d) of this AD, repair it in accordance with a method 
approved by the Manager, Los Angeles ACO.
    (e) Group 2, Condition 3. If the visual inspection required by 
paragraph (a) of this AD reveals that the corners of the doorjamb of 
the forward service door have been modified, but not in accordance 
with the DC-9 SRM or Service Rework Drawing, prior to further 
flight, repair it 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 (61 FR 31009).
    (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 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.

    (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 in paragraphs (a), (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 DC9-53-279, dated December 10, 1996, and Revision 
01, dated May 6, 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 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.
    (j) This amendment becomes effective on January 26, 1999.

    Issued in Renton, Washington, on December 11, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-33388 Filed 12-21-98; 8:45 am]
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