Airworthiness Directives; Boeing Model 737-100, -200, -300, -400, and -500 Series Airplanes

[Federal Register Volume 62, Number 240 (Monday, December 15, 1997)]
[Rules and Regulations]
[Pages 65600-65601]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-32609]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-259-AD; Amendment 39-10247; AD 97-26-04]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -300, -400, 
and -500 Series Airplanes

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 all Boeing Model 737-100, -200, -300, -400, and -500 
series airplanes. This amendment requires a one-time inspection to 
determine if certain ailerons are installed on the airplane. This 
amendment also requires removing any defective aileron, scrapping it, 
and replacing it with a new or serviceable aileron. This amendment is 
prompted by reports of failure of the aileron due to an inappropriate 
repair procedure. The actions specified in this AD are intended to 
detect and correct defective ailerons, which could result in in-flight 
separation of an aileron from the airplane and consequent reduced 
controllability of the airplane.

DATES: Effective December 30, 1997.
    Comments for inclusion in the Rules Docket must be received on or 
before February 13, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-259-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.

FOR FURTHER INFORMATION CONTACT: Greg Schneider or Nenita Odesa, 
Aerospace Engineers, Airframe Branch, ANM-120S, FAA, Transport Airplane 
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056; telephone (425) 227-2028 or (425) 
227-2557; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received two reports of failure 
of the aileron on Boeing Model 737 series airplanes. In one incident, a 
two-foot section of an aileron separated from the airplane during 
descent, which resulted in vibration of the flight controls. In the 
second incident, 30 percent of an aileron separated from the airplane 
during climb. The flightcrew had to input a significant amount of trim 
to straighten the wings to a level position prior to landing. This 
airplane had accumulated 34 flight cycles since its ailerons were 
rebuilt by Tramco Inc. (doing business as BFGoodrich (BFG) Aerospace, 
Repair Station HN6R593N).
    Investigation revealed that the cause of these failures has been 
attributed to an inappropriate repair procedure accomplished by BFG 
Aerospace. During the process of rebuilding ailerons, part number 65-
46454-XX, for Boeing Model 737-100, -200, -300, -400, and -500 series 
airplanes, BFG Aerospace did not use proper procedures in the 
preparation of the aileron surface prior to the lay-up of the skin 
panel. As a result, the contact surface between the skin and core did 
not provide adequate adhesion properties for the bonded skin panel.
    BFG Aerospace has not located all of the defective ailerons and has 
not provided documentation which verifies removal of the defective 
ailerons from service.
    Defective ailerons that are installed on an airplane, if not 
detected and corrected, could result in in-flight separation of an 
aileron from the airplane, which could result in 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 737-100, -200, -300, -400, and -
500 series airplanes of the same type design, this AD is being issued 
to detect defective ailerons installed on an airplane, which could 
result in in-flight separation of an aileron from the airplane and 
consequent reduced controllability of the airplane. This AD requires a 
one-time visual inspection to determine if certain ailerons are 
installed on the airplane. This AD also requires removing any defective 
aileron, scrapping it, replacing it with a new or serviceable aileron, 
and submitting an inspection report to the FAA, if necessary.

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, 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

[[Page 65601]]

Docket Number 97-NM-259-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:

97-26-04  Boeing: Amendment 39-10247. Docket 97-NM-259-AD.

    Applicability: All Model 737-100, -200, -300, -400, and -500 
series airplanes, 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 detect defective ailerons installed on an airplane, which 
could result in in-flight separation of an aileron from the airplane 
and consequent reduced controllability of the airplane, accomplish 
the following:
    (a) Within 60 days after the effective date of this AD, perform 
a one-time visual inspection to determine if an aileron repaired by 
Tramco Inc. (doing business as BFGoodrich Aerospace, Repair Station 
HN6R593N) having any of the following serial numbers is installed on 
the airplane:

Affected Serial Numbers

BN23
BN49
BN56
BN59
BN167
BN180
BN206
BN236
162
237

    (b) If any aileron is found with an affected serial number 
identified in paragraph (a) of this AD, accomplish paragraphs (b)(1) 
and (b)(2) of this AD.
    (1) Prior to further flight, remove the defective aileron, and 
replace it with a new or serviceable aileron. And
    (2) Within 10 days after accomplishing the inspection required 
by paragraph (a) of this AD, submit a report of any findings of 
ailerons specified in paragraph (a) of this AD to the Manager, FAA, 
Transport Airplane Directorate, Seattle Aircraft Certification 
Office (ACO), 1601 Lind Avenue, SW., Renton, Washington 98055-4056; 
telephone (425) 227-2028; fax (425) 227-1181. Information collection 
requirements contained in this regulation have been approved by the 
Office of Management and Budget (OMB) under the provisions of the 
Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have 
been assigned OMB Control Number 2120-0056.
    (c) As of the effective date of this AD, no person shall install 
on any airplane an aileron having any serial number identified in 
paragraph (a) of this AD.
    (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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (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.
    (f) This amendment becomes effective on December 30, 1997.

    Issued in Renton, Washington, on December 9, 1997.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-32609 Filed 12-12-97; 8:45 am]
BILLING CODE 4910-13-U

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