[Federal Register Volume 63, Number 35 (Monday, February 23, 1998)]
[Rules and Regulations]
[Pages 8850-8851]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-4245]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-30-AD; Amendment 39-10352; AD 98-04-41]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-200 and -300 Series 
Airplanes Equipped With a Main Deck Cargo Door Installed in Accordance 
With Supplemental Type Certificate 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 repetitive inspections to detect cracks 
in the hinge and lift actuator box area of the main deck cargo door and 
upper jamb of the fuselage; and repair or replacement of any cracked 
part with a new part having the same part number. This amendment is 
prompted by a report that, during a periodic heavy maintenance check, 
cracks were found in the upper jamb area of the fuselage and in the 
main deck cargo door. The actions specified in this AD are intended to 
detect and correct such cracking, which could result in reduced 
structural integrity of the main cargo door and/or fuselage, and 
consequent loss or opening of the main deck cargo door while the 
airplane is in flight, or reduced controllability of the airplane.

DATES: Effective March 10, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before April 24, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-30-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056.
    Information concerning this amendment may be obtained from or 
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, 
SW., Renton, Washington; or at the FAA, Small Airplane Directorate, 
Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix 
Boulevard, Suite 450, Atlanta, Georgia 30349.

FOR FURTHER INFORMATION CONTACT: Curtis Jackson, Aerospace Engineer, 
Airframe and Propulsion Branch, ACE-117A, FAA, Small Airplane 
Directorate, Atlanta Aircraft Certification Office, One Crown Center, 
1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349; telephone 
(770) 703-6083; fax (770) 703-6097.

SUPPLEMENTARY INFORMATION: The FAA has received a report that, during a 
periodic heavy maintenance check of a Boeing Model 737-300 series 
airplane equipped with a main deck cargo door installed in accordance 
with Supplemental Type Certificate SA2969SO, cracks were found in the 
upper jamb area of the fuselage and in the main cargo door. The cracks 
were between 0.50 inches and 2.35 inches in length. The cause of such 
cracking is unknown at this time. However, several scenarios (e.g., 
improper cargo door operations during loading and unloading of cargo, 
and improper fastener locations) are being examined at this time to 
determine a possible cause of the cracking.
    Cracking in the upper jamb area of the fuselage or in the main deck 
cargo door, if not corrected, could result in reduced structural 
integrity of the main deck cargo door and/or fuselage, and consequent 
loss or opening of the main deck cargo door while the airplane is in 
flight, or reduced controllability of the airplane.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other Boeing Model 737-200 and -300 series 
airplanes, equipped with a main deck cargo door installed in accordance 
with Supplemental Type Certificate SA2969SO, of the same type design, 
this AD is being issued to detect and correct cracking in the upper 
jamb area of the fuselage and in the main deck cargo door; such 
cracking could result in reduced structural integrity of the main deck 
cargo door and/or fuselage, and consequent loss or opening of the main 
deck cargo door while the airplane is in flight, or reduced 
controllability of the airplane. This AD requires repetitive detailed 
visual inspections to detect cracks in the hinge and lift actuator box 
area of the main deck cargo door and upper jamb of the fuselage; and 
replacement of any cracked part with a new part having the same part 
number, or repair in accordance with a method approved by the FAA.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

Determination of Rule's Effective Date

    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,

[[Page 8851]]

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 98-NM-30-AD.'' The postcard will be date stamped and 
returned to the commenter.

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.
    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, 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:

98-04-41  Boeing: Amendment 39-10352. Docket 98-NM-30-AD.

    Applicability: Model 737-200 and -300 series airplanes equipped 
with a main deck cargo door 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 
otherwise 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 (b) 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 detect and correct cracking in the upper jamb area of the 
fuselage and in the main cargo door, which could result in reduced 
structural integrity of the main cargo door and/or fuselage, and 
consequent loss or opening of the main cargo door while the airplane 
is in flight, or reduced controllability of the airplane, accomplish 
the following:
    (a) Within 10 days after the effective date of this AD, and 
thereafter at intevals not to exceed 600 flight cycles, perform a 
detailed visual inspection to detect cracks in the hinge and lift 
actuator box area of the main deck cargo door and upper jamb of the 
fuselage. Pay particular attention to the upper frame of the 
fuselage and upper jamb frames of the main deck cargo door, primary 
longeron, and clips of the fuselage, primarily in the hinge and lift 
actuator box area. If any crack is detected, prior to further 
flight, replace the cracked part with a new part having the same 
part number, or repair in accordance with a method approved by the 
Manager, Atlanta Aircraft Certification Office (ACO), FAA, Small 
Airplane Directorate.
    (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, Atlanta 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.

    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 
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) This amendment becomes effective on March 10, 1998.

    Issued in Renton, Washington, on February 12, 1998.
Gilbert L. Thompson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-4245 Filed 2-20-98; 8:45 am]
BILLING CODE 4910-13-U