[Federal Register Volume 66, Number 91 (Thursday, May 10, 2001)]
[Rules and Regulations]
[Pages 23836-23838]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-11455]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-85-AD; Amendment 39-12222; AD 2001-09-15]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-200 and -300 Series 
Airplanes Equipped with Cargo Doors Installed in Accordance With 
Supplemental Type Certificate (STC) SA2969SO

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Boeing Model 737-200 and -300 series 
airplanes, that currently requires repetitive inspections to detect 
cracking in the radii on the support angles on the lower jamb (latch 
lug fittings) of the main deck cargo door, and replacement of cracked 
parts. This amendment adds a requirement for installation of redesigned 
lower jamb latch support angles in the main cargo door surround 
structure, which would terminate the repetitive inspections. This 
amendment is prompted by the development of a modification that will 
provide better protection of the subject area against effects of 
structural fatigue. The actions specified by this AD are intended to 
prevent in-flight separation of the main deck cargo door from the 
airplane due to fatigue cracking on the support angles on the lower 
door jamb.

DATES: Effective June 14, 2001.
    The incorporation by reference of Pemco Service Bulletin 737-53-
0003, Revision 4, dated February 22, 1995; and Pemco Service Bulletin 
737-53-0003, Revision 5, dated March 25, 1999; as listed in the 
regulations, is approved by the Director of the Federal Register as of 
June 14, 2001.
    The incorporation by reference of Pemco Alert Service Letter 737-
53-0003, Revision 3, dated December 22, 1994, as listed in the 
regulations, was approved previously by the Director of the Federal 
Register as of January 24, 1995 (60 FR 2323, January 9, 1995).

ADDRESSES: The service information referenced in this AD may be 
obtained from Pemco Aeroplex, Inc., P.O. Box 2287, Birmingham, Alabama 
35201-2287. 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, Atlanta 
Aircraft Certification Office, One Crown Center, 1895 Phoenix 
Boulevard, suite 450, Atlanta, Georgia; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: William Culler, Airframe and 
Propulsion Branch, ACE-117A, FAA, Atlanta Aircraft Certification 
Office, One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, 
Georgia 30337-2748; telephone (770) 703-6084; fax (770) 703-6097.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 95-01-06 R1, 
amendment 39-9449 (60 FR 62192, December 5, 1995), which is applicable 
to certain Boeing Model 737-200 and -300 series airplanes, was 
published in the Federal Register on November 22, 1999 (64 FR 63757). 
The action proposed to continue to require repetitive inspections to 
detect cracking in the radii on the support angles on the lower jamb 
(latch lug fittings) of the main deck cargo door, and replacement of 
cracked parts. That action also adds a requirement for installation of 
redesigned lower jamb latch support angles in the main cargo door 
surround structure, which would terminate the repetitive inspections.

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. Two commenters state that the airplanes they 
operate would not be affected by the proposed rule.

Include Additional Service Information

    One commenter asks that Pemco Service Bulletin 737-53-0005, dated 
November 18, 1997, which specifies alignment of the door latch base and 
frames, be included as an alternative method of compliance in paragraph 
(c)(1) of the proposed rule. The commenter also asks that the actions 
specified in that service bulletin be added to the proposed rule as 
terminating action for the requirements of AD 95-01-06 R1 (above). The 
commenter states that its fleet was modified per the service bulletin 
referenced in the proposed rule, but one airplane was misaligned 
between the door latch base and fuselage framing at FS 490.8. The 
commenter accomplished the alignment specified in service bulletin 737-
53-0005.
    The FAA does not concur with the commenter's requests. The FAA does 
not find it necessary to revise this AD to include special instructions 
for airplanes modified with another service bulletin. Operators should 
note that most AD actions address modifications affecting the subject 
area of the AD using the note that appears as Note 1 of this AD, which 
states, ``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 (AMOC) in accordance with paragraph (c)(1) of this AD.'' The 
AMOC letter would be issued to the operator by the appropriate office, 
as stated in paragraph (c)(1).
    Additionally, the service bulletin referenced in the final rule 
specifies installation of redesigned lower jamb latch support angles in 
the main cargo door surround structure, which would terminate the 
repetitive inspections.

[[Page 23837]]

Modification of the door latch base for better alignment is a separate 
issue that was not addressed in the proposed rule, and would not meet 
the requirements for the terminating action. No change to the final 
rule is necessary in this regard.

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 as proposed.

Cost Impact

    There are approximately 32 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 2 airplanes of U.S. registry 
will be affected by this AD.
    The inspection that is currently required by AD 95-01-06 R1, and 
retained in this AD, takes approximately 8 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 actions on 
U.S. operators is estimated to be $480 per airplane, per inspection 
cycle.
    The new installation that is required by this AD takes 
approximately 500 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts will cost approximately 
$9,700 per airplane. Based on these figures, the cost impact of the 
requirements of this AD on U.S. operators is estimated to be $79,400, 
or $39,700 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. 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 removing amendment 39-9449 (60 FR 
62192, December 5, 1995), and by adding a new airworthiness directive 
(AD), amendment 39-12222, to read as follows:

2001-09-15  Boeing: Amendment 39-12222. Docket 99-NM-85-AD. 
Supersedes AD 95-01-06 R1, Amendment 39-9449.

    Applicability: Model 737-200 and -300 series airplanes equipped 
with main deck cargo doors installed in accordance with supplemental 
type certificate (STC) SA2969SO, 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 (c)(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 in-flight separation of the main deck cargo door from 
the airplane, accomplish the following:

    Note 2: This AD references Pemco Alert Service Letter 737-53-
0003, Revision 3, dated December 22, 1994; Pemco Service Bulletin 
737-53-0003, Revision 4, dated February 22, 1995; and Pemco Service 
Bulletin 737-53-0003, Revision 5, dated March 25, 1999; for 
information concerning inspection and replacement procedures. In 
addition, this AD specifies replacement requirements different from 
those included in the service letter or service bulletin. Where 
there are differences between the AD and the service letter or 
service bulletin, the AD prevails.

Restatement of Requirements AD 95-01-06 R1

Repetitive Inspections

    (a) Within 50 flight cycles after January 24, 1995 (the 
effective date of AD 95-01-06, amendment 39-9117), or within 50 
flight cycles after installation of STC SA2969SO, whichever occurs 
later, perform a detailed visual inspection to detect cracking in 
the radii on the support angles on the lower jamb of the main deck 
cargo door, in accordance with Pemco Alert Service Letter 737-53-
0003, Revision 3, dated December 22, 1994.
    (1) If no cracking is detected, repeat the detailed visual 
inspection thereafter at intervals not to exceed 450 flight cycles.
    (2) If any cracking is detected, prior to further flight, 
replace the cracked part with a new part in accordance with the 
alert service letter. Repeat the detailed visual inspection 
thereafter at intervals not to exceed 450 flight cycles.

    Note 3: For the purposes of this AD, a detailed visual 
inspection is defined as: ``An intensive visual examination of a 
specific structural area, system, installation, or assembly to 
detect damage, failure, or irregularity. Available lighting is 
normally supplemented with a direct source of good lighting at 
intensity deemed appropriate by the inspector. Inspection aids such 
as mirror, magnifying lenses, etc., may be used. Surface cleaning 
and elaborate access procedures may be required.''

New Requirements of This AD

Terminating Action

    (b) Within 1,500 flight cycles after the effective date of this 
AD, install redesigned lower jamb latch lug support angles in the 
main cargo door surround structure in accordance with Pemco Service 
Bulletin 737-53-0003, Revision 4, dated February 22, 1995, or 
Revision 5, dated March 25, 1999. This action constitutes 
terminating action for the requirements of this AD.

Alternative Methods of Compliance

    (c)(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, Atlanta Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance

[[Page 23838]]

Inspector, who may add comments and then send it to the Manager, 
Atlanta ACO.
    (2) Alternative methods of compliance, approved previously in 
accordance with AD 95-01-06 R1, amendment 39-9449, are approved as 
alternative methods of compliance with paragraphs (a) and (b) of 
this AD.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Atlanta ACO.

Special Flight Permits

    (d) 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

    (e) The actions shall be done in accordance with Pemco Alert 
Service Letter 737-53-0003, Revision 3, dated December 22, 1994; 
Pemco Service Bulletin 737-53-0003, Revision 4, dated February 22, 
1995, or Pemco Service Bulletin 737-53-0003, Revision 5, dated March 
25, 1999; as applicable.
    (1) The incorporation by reference of Pemco Service Bulletin 
737-53-0003, Revision 4, dated February 22, 1995; and Pemco Service 
Bulletin 737-53-0003, Revision 5, dated March 25, 1999; is approved 
by the Director of the Federal Register in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51.
    (2) The incorporation by reference of Pemco Alert Service Letter 
737-53-0003, Revision 3, dated December 22, 1994, was approved 
previously by the Director of the Federal Register as of January 24, 
1995 (60 FR 2323, January 9, 1995).
    (3) Copies may be obtained from Pemco Aeroplex, Inc., P.O. Box 
2287, Birmingham, Alabama 35201-2287. Copies may be inspected at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the FAA, Atlanta ACO, One Crown Center, 1895 
Phoenix Boulevard, suite 450, Atlanta, Georgia; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

Effective Date

    (f) This amendment becomes effective on June 14, 2001.

    Issued in Renton, Washington, on May 1, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-11455 Filed 5-9-01; 8:45 am]
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