[Federal Register Volume 60, Number 5 (Monday, January 9, 1995)]
[Rules and Regulations]
[Pages 2323-2325]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-199]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-247-AD; Amendment 39-9117; AD 95-01-06]


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; 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 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 is prompted by reports of premature fatigue cracking on the 
support angles on the lower jamb of the main deck cargo door. The 
actions specified in 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 January 24, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 24, 1995.
    Comments for inclusion in the Rules Docket must be received on or 
before March 10, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-247-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    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 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-
7358; 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, an operator reported that it 
experienced difficulty in pressurizing a Boeing Model 737-300 series 
airplane. Investigation revealed that the airplane could not be 
pressurized because the main deck cargo door would not seal properly. 
Further investigation revealed that 13 of the 16 support angles on the 
lower jamb of the main deck cargo door [[Page 2324]] had failed due to 
premature fatigue cracking.
    Following this incident, the FAA has received additional reports 
from operators of Boeing Model 737-200 and -300 series airplanes of 
fatigue cracking on the support angles on the lower jamb of the main 
deck cargo door.
    Pemco Aeroplex installed main deck cargo doors on all of these 
airplanes in accordance with supplemental type certificate (STC) 
SA2969SO. Several of these airplanes had accumulated less than 4,000 
total flight cycles since installation of the main deck cargo door.
    Such cracking, if not detected and corrected in a timely manner, 
could result in in-flight separation of the main deck cargo door from 
the airplane.
    The FAA has reviewed and approved Pemco Alert Service Letter 737-
53-0003, Revision 3, dated December 22, 1994, which describes 
procedures for repetitive visual inspections to detect cracking in the 
radii on the support angles on the lower jamb of the main deck cargo 
door and replacement of cracked parts with new parts. This service 
letter permits further flight with parts that are cracked within 
certain limits.
    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 in-flight separation of the main deck cargo 
door from the airplane. This AD requires repetitive visual inspections 
to detect cracking in the radii on the support angles on the lower jamb 
of the main deck cargo door and replacement of cracked parts with new 
parts. The actions are required to be accomplished in accordance with 
the service letter described previously. However, unlike the service 
letter, this AD does not permit further flight with cracked parts. The 
FAA has determined that all cracked parts must be replaced prior to 
further flight.
    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.
    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 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 94-NM-247-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:

95-01-06  Boeing: Amendment 39-9117. Docket 94-NM-247-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 [[Page 2325]] 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 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, for information 
concerning inspection and replacement procedures. In addition, this 
AD specifies replacement requirements different from those included 
in the service letter. Where there are differences between the AD 
and the service letter, the AD prevails.

    (a) Within 50 flight cycles after the effective date of this AD 
or within 50 flight cycles after installation of STC SA2969SO, 
whichever occurs later, perform a 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 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 
service letter. Repeat the visual inspection thereafter at intervals 
not to exceed 450 flight cycles.
    (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, Transport Airplane 
Directorate, Seattle Aircraft Certification (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.

    (c) 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.
    (d) The inspection and replacement procedures shall be done in 
accordance with Pemco Alert Service Letter 737-53-0003, Revision 3, 
dated December 22, 1994. 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 January 24, 1995.

    Issued in Renton, Washington, on December 29, 1994.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-199 Filed 1-6-95; 8:45 am]
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