AD Amdt-39-9175

[Federal Register Volume 60, Number 54 (Tuesday, March 21, 1995)]
[Rules and Regulations]
[Pages 14897-14899]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 95-6319]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-23-AD; Amendment 39-9175; AD 95-06-05]


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Boeing Model 737-200 and -300 series 
airplanes. This action requires inspections to detect cracking of the 
fuselage frames at certain locations below the lower jamb of the upper 
deck main cargo door, and repair, if necessary. This amendment is 
prompted by reports of fatigue cracking in the fuselage frames at these 
locations. The actions specified in this AD are intended to prevent 
rapid decompression of the airplane due to fatigue cracking in the 
fuselage frames of the main deck cargo door.

DATES: Effective April 5, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 5, 1995.
    Comments for inclusion in the Rules Docket must be received on or 
before May 22, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-23-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056.
    The service information referenced in this AD may be obtained from 
Pemco Aeroplex, Incorporated, P.O. Box 2287, Birmingham, Alabama 35201-
2287. This information may be examined at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, 
Small Airplane Directorate, Atlanta Aircraft Certification Office, 
Campus Building, 1701 Columbia Avenue, Suite 2-160, College Park, 
Georgia; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Curtis Jackson, Aerospace Engineer, 
Airframe Branch, ACE-120A, FAA, Small Airplane Directorate, Atlanta 
Aircraft Certification Office, Campus Building, 1701 Columbia Avenue, 
Suite 2-160, College Park, Georgia 30337-2748; telephone (404) 305-
7348; fax (404) 305-7348; or Della Swartz, Aerospace Engineer, Airframe 
Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (206) 227-2785; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION: Recently, two operators reported finding 
fatigue cracks in the fuselage frames below the lower jamb of the main 
deck cargo door between stringers 20L and 21L at water line 180 on 
Boeing Model 737-300 series airplanes. The cracking was randomly 
located in various areas of the fuselage frames and may have initiated 
at frame stations 380, 400, 420, 440, 460, and/or 480 at the radius of 
the frame webs that were modified in accordance with supplemental type 
certificate (STC) SA2969SO.
    Such cracking, if not detected and corrected in a timely manner, 
could result in rapid decompression of the airplane.
    Pemco Aeroplex installed main deck cargo doors on Boeing Model 737-
200 and -300 series airplanes in accordance with STC SA2969SO. 
Therefore, the FAA has determined that Boeing Model 737-200 series 
airplanes are also subject to the same unsafe condition.
    The FAA has reviewed and approved Pemco Alert Service Letter 737-
53-0004, dated January 10, 1995, which describes procedures for 
detailed close visual inspections to detect cracking of the fuselage 
frames below the lower jamb of the upper deck main cargo door between 
stringers 20L and 21L at water line 180 at frame stations 380, 400, 
420, 440, 460, and 480, and repair of any cracking found.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD is 
being issued to prevent rapid decompression of the airplane due to 
cracking of the fuselage frames below the lower jamb of the upper deck 
main cargo door. This AD requires detailed close visual inspections to 
detect cracking of the fuselage frames below the lower jamb of the 
upper deck main cargo door, and repair, if necessary. The actions are 
required to be accomplished in accordance with the alert service letter 
described previously.
    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

    [[Page 14898]] Note: The FAA previously issued AD 95-01-06, 
amendment 39-9117 (60 FR 2323, January 9, 1995), which is applicable 
to the same airplanes affected by this new AD action. AD 95-01-06 
requires inspections to detect cracking in the radii on the support 
angles on the lower jamb (latch lug fittings) of the main cargo 
door, and replacement of cracked parts. The requirements of AD 95-
01-06 are different and separate from the requirements of this new 
AD.


    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that, in general, 
some operators may misunderstand the legal effect of AD's on airplanes 
that are identified in the applicability provision of the AD, but that 
have been altered or repaired in the area addressed by the AD. The FAA 
points out that all airplanes identified in the applicability provision 
of an AD are legally subject to the AD. If an airplane has been altered 
or repaired in the affected area in such a way as to affect compliance 
with the AD, the owner or operator is required to obtain FAA approval 
for an alternative method of compliance with the AD, in accordance with 
the paragraph of each AD that provides for such approvals. A note has 
been included in this rule to clarify this long-standing requirement.
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications shall identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 95-NM-23-AD.'' The postcard will be date stamped and 
returned to the commenter.
    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.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

95-06-05  Boeing: Amendment 39-9175. Docket 95-NM-23-AD.

    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 use the authority 
provided in paragraph (b) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition; or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent rapid decompression due to cracking of the fuselage 
frames below the lower jamb of the upper deck main cargo door, 
accomplish the following:
    (a) Within 50 flight cycles after the effective date of this AD 
or within 50 flight cycles after the installation of STC SA2969SO, 
whichever occurs later, perform a detailed close visual inspection 
to detect cracking of the fuselage frames below the lower jamb of 
the upper deck main cargo door between stringers 20L and 21L at 
water line 180 at frame stations 380, 400, 420, 440, 460, and 480, 
in accordance with Pemco Alert Service Letter 737-53-0004, dated 
January 10, 1995.
    (1) If no cracking is detected, repeat the visual inspection 
thereafter at intervals not to exceed 450 flight cycles until the 
repair described in Pemco Alert Service Letter 737-53-0004, dated 
January 10, 1995, has been accomplished.
    (2) If any cracking is detected, prior to further flight, repair 
in accordance with Pemco Alert Service Letter 737-53-0004, dated 
January 10, 1995.
    (b) 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, FAA, Small Airplane Directorate, 
Atlanta Aircraft Certification Office (ACO). Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Atlanta ACO.

    [[Page 14899]] Note 2: Information concerning the existence of 
approved alternative methods of compliance with this AD, if any, may 
be obtained from the Atlanta ACO.
    (c) Special flight permits may be issued in accordance with 
Secs. 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.
    (d) The inspections and repair shall be done in accordance with 
Pemco Alert Service Letter 737-53-0004, including Appendices I and 
II dated January 10, 1995. 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 Pemco 
Aeroplex, Incorporated, 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, Small Airplane Directorate, Atlanta Aircraft Certification 
Office, Campus Building, 1701 Columbia Avenue, Suite 2-160, College 
Park, Georgia; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.
    (e) This amendment becomes effective on April 5, 1995.

    Issued in Renton, Washington, on March 9, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-6319 Filed 3-20-95; 8:45 am]
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