[Federal Register Volume 64, Number 112 (Friday, June 11, 1999)]
[Rules and Regulations]
[Pages 31488-31490]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-14821]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-273-AD; Amendment 39-11192; AD 99-12-08]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-200C Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to all Boeing Model 737-200C series airplanes, that 
currently requires a one-time external detailed visual inspection to 
detect cracks of the fuselage skin in the lower lobe cargo compartment; 
repetitive internal detailed visual inspections to detect cracks of the 
frames in the lower lobe cargo compartment; and repair of cracked 
parts. That AD also provides for an optional preventative modification 
that constitutes terminating action for the repetitive inspections. 
This amendment requires accomplishment of the previously optional 
terminating modification. This amendment is prompted by reports of 
cracking in the body frames between stringers 19 left and 25 left and 
at body stations 360 to 500B. The actions specified by this AD are 
intended to prevent opening or loss of the cargo door during flight, 
and consequent rapid decompression of the airplane.

DATES: Effective July 16, 1999.
    The incorporation by reference of Boeing Alert Service Bulletin 
737-53A1160, dated October 24, 1991; and Boeing Service Bulletin 737-
53A1160, Revision 1, dated April 29, 1993; as listed in the 
regulations, was approved previously by the Director of the Federal 
Register as of August 9, 1993 (58 FR 36863, July 9, 1993).

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. 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 Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Nenita Odesa, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2557; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 93-13-02, 
amendment 39-8615 (58 FR 36863, July 9, 1993), which is applicable to 
all Boeing Model 737-200C series airplanes, was published in the 
Federal Register on February 1, 1999 (64 FR 4791). The action proposed 
to continue to require a one-time external detailed visual inspection 
to detect cracks of the fuselage skin in the lower lobe cargo 
compartment; repetitive internal detailed visual inspections to detect 
cracks of the frames in the lower lobe cargo compartment; and repair of 
cracked parts. The action also proposed to require accomplishment of 
the previously optional terminating modification.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due

[[Page 31489]]

consideration has been given to the single comment received.
    The commenter supports the proposed rule.

Conclusion

    After careful review of the available data, including the comment 
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 90 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 18 airplanes of U.S. registry 
will be affected by this AD.
    The inspections that are currently required by AD 93-13-02, and 
retained in this AD, take approximately 12 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact of the currently required inspections on 
U.S. operators is estimated to be $12,960, or $720 per airplane, per 
inspection cycle.
    The new modification that is required by this new AD will take 
approximately 160 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts will cost approximately 
$5,500 per airplane. Based on these figures, the cost impact of the 
modification required by this AD on U.S. operators is estimated to be 
$271,800, or $15,100 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-8615 (58 FR 
36863, July 9, 1993), and by adding a new airworthiness directive (AD), 
amendment 39-11192, to read as follows:

99-12-08  Boeing: Amendment 39-11192. Docket 98-NM-273-AD. 
Supersedes AD 93-13-02, Amendment 39-8615.

    Applicability: All Model 737-200C series airplanes, 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 (d)(1) 
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 prevent opening or loss of the cargo door during flight, and 
consequent rapid decompression of the airplane, accomplish the 
following:

Restatement of Requirements of AD          93-13-02

    (a) Prior to the accumulation of 29,000 flight cycles or within 
250 flight cycles after August 9, 1993 (the effective date AD 93-13-
02, amendment 39-8615), whichever occurs later, accomplish an 
external detailed visual inspection to detect cracks of the fuselage 
skin between stringers 19 left and 25 left and at body stations 360 
to 540, in accordance with Boeing Alert Service Bulletin 737-
53A1160, dated October 24, 1991; or Boeing Service Bulletin 737-
53A1160, Revision 1, dated April 29, 1993. If any crack is found, 
prior to further flight, accomplish the requirements of paragraphs 
(a)(1) and (a)(2) of this AD.
    (1) Perform an internal detailed visual inspection to detect 
cracks of the frames between stringers 19 left and 25 left and at 
body stations 360 to 500B, in accordance with either service 
bulletin.
    (2) Repair all cracks in accordance with a method approved by 
the Manager, Seattle Aircraft Certification Office (ACO), FAA, 
Transport Airplane Directorate.
    (b) Within 3,000 flight cycles after completing the requirements 
of paragraph (a) of this AD, unless accomplished within the last 
6,000 flight cycles prior to August 9, 1993, perform an internal 
detailed visual inspection to detect cracks of the frames between 
stringers 19 left and 25 left and at body stations 360 to 500B, in 
accordance with Boeing Alert Service Bulletin 737-53A1160, dated 
October 24, 1991; or Boeing Service Bulletin 737-53A1160, Revision 
1, dated April 29, 1993. Thereafter, repeat the internal detailed 
visual inspection at intervals not to exceed 9,000 flight cycles. If 
any crack is found, prior to further flight, accomplish the 
requirements of paragraph (b)(1) or (b)(2) of this AD, as 
applicable.
    (1) If any crack is found that does not exceed the limits 
specified in the Boeing 737 Structural Repair Manual (SRM), repair 
the crack in accordance with the Boeing 737 SRM. Repeat the internal 
detailed visual inspection thereafter at intervals not to exceed 
9,000 flight cycles.
    (2) If any crack is found that exceeds the limits specified in 
the Boeing 737 SRM, repair the crack in accordance with a method 
approved by the Manager, Seattle ACO. Repeat the internal detailed 
visual inspection thereafter at intervals not to exceed 9,000 flight 
cycles.

New Requirements of This AD

    (c) Prior to the accumulation of 75,000 total flight cycles, or 
within 3,000 flight cycles after the effective date of this AD, 
whichever occurs later, install doublers on the frames located 
between stringers 19 left and 25 left and at body stations 360 to 
500B, in accordance with Boeing Service Bulletin 737-53A1160, 
Revision 1, dated April 29, 1993. Accomplishment of this 
modification constitutes terminating action for the requirements of 
this AD.

Alternative Methods of Compliance

    (d)(1) 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, Seattle ACO. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Seattle ACO.
    (d)(2) Alternative methods of compliance approved previously in 
accordance with AD 93-13-02, amendment 39-8615, are

[[Page 31490]]

approved as alternative methods of compliance with this AD.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (e) 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.

Incorporation by Reference

    (f) Except as provided by paragraphs (a)(2), (b)(1), and (b)(2) 
of this AD, the actions shall be done in accordance with Boeing 
Alert Service Bulletin 737-53A1160, dated October 24, 1991; or 
Boeing Service Bulletin 737-53A1160, Revision 1, dated April 29, 
1993. The incorporation by reference of these documents was approved 
previously by the Director of the Federal Register as of August 9, 
1993 (58 FR 36863, July 9, 1993). Copies may be obtained from Boeing 
Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-
2207. 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.
    (g) This amendment becomes effective on July 16, 1999.

    Issued in Renton, Washington, on June 4, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-14821 Filed 6-10-99; 8:45 am]
BILLING CODE 4910-13-P