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

[Federal Register Volume 67, Number 211 (Thursday, October 31, 2002)]
[Rules and Regulations]
[Pages 66316-66318]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-27315]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-214-AD; Amendment 39-12929; AD 2002-22-05]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
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, -200C, -300, -400, and 
-500 series airplanes. This action requires repetitive inspections to 
find cracks, fractures, or corrosion of each carriage spindle of the 
left and right outboard mid-flaps; and corrective action, if necessary. 
This action also provides for an optional action of overhaul or 
replacement of the carriage spindles, which would extend the repetitive 
inspection interval. This action is necessary to prevent severe flap 
asymmetry due to fractures of the carriage spindles on an outboard mid-
flap, which could result in reduced control or loss of controllability 
of the airplane. This action is intended to address the identified 
unsafe condition.

DATES: Effective November 15, 2002.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of November 15, 2002.
    Comments for inclusion in the Rules Docket must be received on or 
before December 30, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-214-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-214-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in this AD may be obtained from 
Boeing Commercial Airplane Group, PO Box 3707, Seattle, Washington 
98124-2207. This information may be examined at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at 
the Office of the Federal Register, 800 North Capitol Street, NW., 
suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Technical Information: Sue Lucier, 
Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2186; fax (425) 227-1181.
    Other Information: Sandi Carli, Airworthiness Directive Technical 
Editor/Writer; telephone (425) 687-4243, fax (425) 227-1232. Questions 
or comments may also be sent via the Internet using the following 
address: [email protected]. Questions or comments sent via the 
Internet as attached electronic files must be formatted in Microsoft 
Word 97 for Windows or ASCII text.

SUPPLEMENTARY INFORMATION: The FAA has received reports indicating 
fractures of the carriage spindles of the outboard mid-flaps on certain 
Boeing Model 737 series airplanes. The fractures resulted from stress-
corrosion cracking. The most critical section for a fracture is at the 
forward end of the spindle; two of the thirteen reported fractures 
occurred in this area on airplanes that had accumulated between 4,198 
and 43,919 total flight cycles. In a recent incident, dual failure of 
the carriage spindles occurred and one of the spindles failed at a 
location critical for continued flap functionality. If one carriage 
spindle fractures on a flap, it will affect control of flight of the 
airplane. If both the inboard and outboard spindles fracture in the 
critical section on an outboard

[[Page 66317]]

flap, it could result in loss of controllability of the airplane.

Related Rulemaking

    This AD is related to AD 90-17-19, amendment 39-6705 (55 FR 33280, 
August 15, 1990). That AD is applicable to all Boeing Model 747 series 
airplanes, except Model 747SP, and requires periodic inspections of 
both inboard and outboard trailing edge flap carriage spindles for 
cracks and corrosion, and overhaul or replacement, if necessary. That 
AD also requires periodic inspections to detect cracks or corrosion of 
all exposed surfaces of the carriage spindles, including inner bore, 
and aft links; and overhaul or replacement, if necessary. That AD also 
shortens certain compliance intervals to ensure continued 
airworthiness.
    This AD requires similar actions for all Boeing Model 737-100, -
200, -200C, -300, -400, and -500 series airplanes, because the carriage 
spindles on the outboard mid-flaps are very similar to the carriage 
spindles on Model 747 series airplanes.

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Alert Service Bulletin 737-
57A1277, dated July 25, 2002, which describes procedures for repetitive 
nondestructive test (NDT) inspections to find cracks, fractures, or 
corrosion of each carriage spindle of the left and right outboard mid-
flaps; and corrective action, if necessary. The corrective action 
includes overhaul or replacement of the carriage spindle if any cracks, 
fractures, or corrosion are found. The service bulletin also recommends 
that a report be sent to the manufacturer if a crack or fracture of any 
carriage spindle is found. Accomplishment of the actions specified in 
the service bulletin is intended to adequately address the identified 
unsafe condition

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, the 
actions in this AD are required to be accomplished in accordance with 
the service bulletin described previously, except as discussed below.

Differences Between AD and Service Information

    The service bulletin explicitly specifies doing a NDT inspection 
for cracks or fractures of each carriage spindle, and indicates that 
operators should look for cracking or corrosion of the exposed portion 
of the spindle. We infer that this description is that of a general 
visual inspection; therefore, this AD adds a general visual inspection 
for cracks, fractures, or corrosion of the spindle. We have added a 
note to this AD to define such an inspection.
    Although the service bulletin recommends that operators report 
inspection findings of any crack or fracture in the carriage spindle to 
the manufacturer, this AD does not contain such a reporting 
requirement.

Interim Action

    This is considered to be interim action. We are currently 
considering mandating overhaul or replacement of the carriage spindles, 
which will extend the interval for the repetitive inspections required 
by this AD action. This action is similar to that required by AD 90-17-
19, discussed above. However, the planned compliance time for the 
overhaul or replacement action is sufficiently long so that notice and 
opportunity for prior public comment will be practicable.

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.
    Submit comments using the following format:
    [sbull] Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
    [sbull] For each issue, state what specific change to the AD is 
being requested.
    [sbull] Include justification (e.g., reasons or data) for each 
request.
    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 2002-NM-214-AD.'' The postcard will be date stamped 
and returned to the commenter.

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.
    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

[[Page 66318]]

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:

2002-22-05 Boeing: Amendment 39-12929. Docket 2002-NM-214-AD.

    Applicability: All Model 737-100, -200, -200C, -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 prevent severe flap asymmetry due to fractures of the 
carriage spindles on an outboard mid-flap, which could result in 
reduced control or loss of controllability of the airplane, 
accomplish the following:

Repetitive Inspections

    (a) Do general visual and nondestructive test (NDT) inspections 
of each carriage spindle (two on each flap) of the left and right 
outboard mid-flaps to find cracks, fractures, or corrosion at the 
later of the times specified in paragraphs (a)(1) and (a)(2) of this 
AD, as applicable, per the Work Instructions of Boeing Alert Service 
Bulletin 737-57A1277, dated July 25, 2002. Repeat the inspection at 
least every 180 days until paragraph (c) of this AD is done.
    (1) Before the accumulation of 12,000 total flight cycles or 8 
years in-service on new or overhauled carriage spindles, whichever 
is first.
    (2) Within 90 days after the effective date of this AD.

    Note 2: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''

Corrective Action

    (b) If any crack, fracture, or corrosion is found during any 
inspection required by paragraph (a) of this AD: Before further 
flight, do the applicable actions for that spindle as specified in 
paragraph (b)(1) or (b)(2) of this AD, per the Work Instructions of 
Boeing Alert Service Bulletin 737-57A1277, dated July 25, 2002. Then 
repeat the inspections required by paragraph (a) of this AD every 
12,000 flight cycles or 8 years, whichever is first; on the 
overhauled or replaced spindle only.
    (1) If any corrosion is found in the carriage spindle, overhaul 
the spindle.
    (2) If any crack or fracture is found in the carriage spindle, 
replace with a new or overhauled carriage spindle.

    Note 3: Although the service bulletin recommends that operators 
report inspection findings of any crack or fracture in the carriage 
spindle to the manufacturer, this AD does not contain such a 
reporting requirement.

Optional Overhaul or Replacement

    (c) Overhaul or replacement, as applicable, of all four carriage 
spindles, per the Work Instructions of Boeing Alert Service Bulletin 
737-57A1277, dated July 25, 2002, extends the repetitive inspection 
interval specified in paragraph (a) of this AD to every 12,000 
flight cycles or 8 years, whichever is first.

Alternative Methods of Compliance

    (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 Aircraft Certification 
Office (ACO), FAA. 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 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (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.

Incorporation by Reference

    (f) The actions shall be done in accordance with Boeing Alert 
Service Bulletin 737-57A1277, dated July 25, 2002. 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 Boeing Commercial Airplane Group, PO 
Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at 
the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., 
Renton, Washington; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

    (g) This amendment becomes effective on November 15, 2002.


    Issued in Renton, Washington, on October 22, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-27315 Filed 10-30-02; 8:45 am]
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