[Federal Register Volume 60, Number 19 (Monday, January 30, 1995)]
[Rules and Regulations]
[Pages 5566-5568]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-1850]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-236-AD; Amendment 39-9129; AD 95-02-10]


Airworthiness Directives; Boeing Model 757 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 certain Boeing Model 757 series airplanes. This action 
requires replacement of the bolts, nuts, and washers that attach the 
support bracket at the Number 4 and Number 5 transmissions to the wing 
flap structure. This amendment is prompted by a report of damage to the 
left inboard trailing edge flap. The actions specified in this AD are 
intended to prevent these airplanes from taking off with broken bolts 
that attach the transmission bracket to the wing flap track structure, 
which could result in the airplane rolling at liftoff.

DATES: Effective February 14, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 14, 1995.
    Comments for inclusion in the Rules Docket must be received on or 
before March 31, 1995.

[[Page 5567]] ADDRESSES: Submit comments in triplicate to the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-236-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The service information referenced in this AD may be obtained from 
Boeing Commercial Airplane Group, P.O. 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: Carrie Sumner, Aerospace Engineer, 
Airframe Branch, ANM-121S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (206) 227-2778; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION: Recently, the FAA has received a report of 
damage to the left inboard trailing edge flap on the wing of a Boeing 
Model 757 series airplane when the flaps were retracted after the 
airplane had landed. Investigation revealed that six bolts on the 
attachment bracket of the inboard flap drive had sheared off when the 
flaps were retracted. Further investigation revealed that the Number 3 
inboard flap outboard drive had disconnected inside the angle gear box, 
while the Number 4 inboard flap inboard drive continued to retract. 
This caused a flap skew, which applied sufficient load on the drive 
screw to fracture the six bolts that attach the Number 4 transmission 
bracket to its mating flap track. Analysis showed that those six bolts, 
which were made of titanium, do not meet the designed limit load. If an 
airplane attempts to take off with broken bolts that attach the 
transmission bracket to the flap track structure, the result may be the 
airplane rolling at liftoff.
    The FAA has reviewed and approved Boeing Alert Service Bulletin 
757-27A0118, dated December 15, 1994, which describes procedures for 
replacement of the six bolts, nuts, and washers that attach the support 
bracket at the Number 4 and Number 5 transmission to the inboard 
trailing edge flap system. The replacement bolts, nuts, and washers 
(kit number 012N8037) are made of Inconel 718 material, which is 
stronger and will sustain the designed limit load.
    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 these airplanes from taking off with broken 
bolts that attach the transmission bracket to the flap track structure, 
which could result in the airplane rolling at liftoff. This AD requires 
replacement of the bolts, nuts, and washers that attach the support 
bracket at the Number 4 and Number 5 transmission to the inboard 
trailing edge flap system, with items made of Inconel 718 material. The 
actions are required to be accomplished in accordance with the alert 
service bulletin described previously.
    This AD applies only to airplanes having line numbers 181 through 
647, inclusive. The subject six-bolt attachment configuration was 
incorporated on airplanes starting at line position 181.
    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-236-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:

95-02-10  Boeing: Amendment 39-9129. Docket 94-NM-236-AD.

    Applicability: Model 757 series airplanes having line numbers 
181 through 647 inclusive, certificated in any category.

    [[Page 5568]] 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 these airplanes from taking off with broken bolts 
that attach the transmission bracket to the flap track structure, 
which could result in the airplane rolling at liftoff, accomplish 
the following:
    (a) Within 60 days after the effective date of this AD, remove 
the bolts, nuts, and washers that attach the support bracket at the 
Number 4 and Number 5 transmission for the inboard trailing edge 
flap system and install kit number 012N8037, in accordance with 
Boeing Alert Service Bulletin 757-27A0118, dated December 15, 1994.
    (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, Seattle Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. 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.

    (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 installation shall be done in accordance with Boeing 
Alert Service Bulletin 757-27A0118, dated December 15, 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 Boeing Commercial Airplane Group, 
P.O. 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.
    (e) This amendment becomes effective on February 14, 1995.

    Issued in Renton, Washington, on January 19, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-1850 Filed 1-27-95; 8:45 am]
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