[Federal Register Volume 66, Number 130 (Friday, July 6, 2001)]
[Rules and Regulations]
[Pages 35533-35535]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-16740]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-403-AD; Amendment 39-12305; AD 2001-13-23]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-700 and -800 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 Boeing Model 737-700 and -800 series airplanes, 
that requires inspections of certain tension bolts at the attachment of 
the aft pressure bulkhead to the fuselage at body station 1016 to 
determine if the correct parts are installed, and corrective action, if 
necessary. The actions specified by this AD are intended to prevent 
fatigue cracking along the bulkhead-to-fuselage attachment, which could 
result in structural failure of the aft pressure bulkhead and 
consequent rapid decompression of the airplane. This action is intended 
to address the identified unsafe condition.

DATES: Effective August 13, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 13, 2001.

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: Scott Fung, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1221; fax (425) 227-1181.

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 Boeing Model 737-700 and -
800 series airplanes was published in the Federal

[[Page 35534]]

Register on April 12, 2001 (66 FR 18880). That action proposed to 
require inspections of certain tension bolts at the attachment of the 
aft pressure bulkhead to the fuselage at body station 1016 to determine 
if the correct parts are installed, and corrective action, if 
necessary.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comment received.
    The Air Transport Association (ATA) of America, on behalf of one of 
its members, states that its member 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 31 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 14 airplanes of U.S. registry 
will be affected by this AD, that it will take approximately 2 work 
hours per airplane to accomplish the required actions, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the AD on U.S. operators is estimated to be $1,680, or 
$120 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. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations adopted herein will not have a substantial direct 
effect 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, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    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:

2001-13-23  Boeing: Amendment 39-12305. Docket 2000-NM-403-AD.

    Applicability: Model 737-700 and -800 series airplanes; line 
numbers 4, 6, 9 through 20 inclusive, 29, and 31 through 46 
inclusive; 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) 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 fatigue cracking along the bulkhead-to-fuselage 
attachment, which could result in structural failure of the aft 
pressure bulkhead and consequent rapid decompression of the 
airplane, accomplish the following:

Inspections and Corrective Actions

    (a) Prior to the accumulation of 3,000 total flight cycles, or 
within 90 days after the effective date of this AD, whichever occurs 
later, do one-time special detailed inspections of tension bolts at 
the attachment of the aft pressure bulkhead to the fuselage at body 
station 1016 to determine whether the correct parts are installed, 
per the Accomplishment Instructions of Boeing Service Bulletin 737-
53-1212, including Appendix A, dated August 13, 1998.
    (1) If any long bolt is found above the main deck floor, do 
paragraphs (a)(1)(i) and (a)(1)(ii) of this AD.
    (i) Before further flight, do a torque test of the nut on the 
long bolt to determine whether the bolt is properly clamped.
    (ii) Replace the bolt and nut, as applicable, with new parts, 
per the service bulletin, except as provided by paragraph (c) of 
this AD. The correct replacement parts are listed in Figure 4 of the 
service bulletin. Do the replacement no later than the compliance 
time specified in the compliance table in Section 1.D. 
(``Compliance'') of the service bulletin. For the purposes of this 
AD, compliance times stated in flight cycles and years are to be 
counted from the time of the inspection per paragraph (a) of this 
AD.
    (2) For any long or short bolt other than those identified in 
paragraph (a)(1) of this AD, replace the bolt and nut, as 
applicable, with new parts, per the service bulletin, except as 
provided by paragraph (c) of this AD. The correct replacement parts 
are listed in Figure 4 of the service bulletin. Do the replacement 
no later than the compliance time specified in the compliance table 
in Section 1.D. (``Compliance'') of the service bulletin. For the 
purposes of this AD, compliance times stated in flight cycles and 
years are to be counted from the time of the inspection per 
paragraph (a) of this AD.

    Note 2: For the purposes of this AD, a special detailed 
inspection is defined as: ``An intensive examination of a specific 
item(s), installation, or assembly to detect damage, failure, or 
irregularity. The examination is likely to make extensive use of 
specialized inspection techniques and/or equipment. Intricate 
cleaning and substantial access or disassembly procedures may be 
required.''

Repetitive Inspections

    (b) Where short bolts are installed between two adjacent 
stringer end fittings or at stringer end fittings, doing repetitive 
inspections of the nuts to determine if bolts are properly clamped, 
per Boeing Service Bulletin 737-53-1212, including Appendix A, dated 
August 13, 1998, extends the compliance time for the replacement of 
bolts, per the compliance table in Section 1.D. (``Compliance'') of 
the service bulletin.

Exception for Certain Repair Conditions

    (c) Where Boeing Service Bulletin 737-53-1212, including 
Appendix A, dated August 13, 1998, specifies to contact Boeing for 
replacement instructions: Before further flight, replace per a 
method approved by the Manager, Seattle Aircraft Certification 
Office

[[Page 35535]]

(ACO), FAA; or per data meeting the type certification basis of the 
airplane approved by a Boeing Company Designated Engineering 
Representative who has been authorized by the Manager, Seattle ACO, 
to make such findings. For a repair method to be approved by the 
Manager, Seattle ACO, as required by this paragraph, the approval 
letter must specifically reference this AD.

Alternative Methods of Compliance

    (d) 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.

    Note 3: 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 paragraph (c) of this AD, the actions 
shall be done in accordance with Boeing Service Bulletin 737-53-
1212, including Appendix A, dated August 13, 1998. 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 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.

Effective Date

    (g) This amendment becomes effective on August 13, 2001.

    Issued in Renton, Washington, on June 27, 2001.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-16740 Filed 7-5-01; 8:45 am]
BILLING CODE 4910-13-U