[Federal Register: November 26, 2007 (Volume 72, Number 226)]
[Proposed Rules]
[Page 65903-65905]
[DOCID:fr26no07-7]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0225; Directorate Identifier 2007-NM-210-AD]
RIN 2120-AA64

Airworthiness Directives; Boeing Model 757 Airplanes Equipped
with Rolls Royce RB211-535E Engines

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Boeing Model 757 airplanes equipped with Rolls Royce RB211-
535E engines. This proposed AD would require repetitive inspections for
signs of damage of the aft hinge fittings and attachment bolts of the
thrust reversers, and related investigative and corrective actions if
necessary. This proposed AD results from reports of several incidents
of bolt failure at the aft hinge fittings of the thrust reversers due
to, among other things, high operational loads. We are proposing this
AD to prevent failure of the attachment bolts and consequent separation
of a thrust reverser from the airplane during flight, which could
result in structural damage to the airplane.

DATES: We must receive comments on this proposed AD by January 10,
2008.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov.
 Follow the instructions for submitting comments.

     Fax:<PHONE_NUMBER>.
     Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room

W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact Boeing
Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov
; or in person at the Docket Management Facility

between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this proposed AD, the regulatory
evaluation, any comments received, and other information. The street
address for the Docket Office (telephone<PHONE_NUMBER>) is in the
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.

FOR FURTHER INFORMATION CONTACT: Jason Deutschman, Aerospace Engineer,
Airframe Branch, ANM-120S, Seattle Aircraft Certification Office, FAA,
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425)
917-6449; fax<PHONE_NUMBER>.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2007-0225;
Directorate Identifier 2007-NM-210-AD'' at the beginning of your
comments. We specifically invite comments on the overall regulatory,
economic, environmental, and energy aspects of this proposed AD. We
will consider all comments received by the closing date and may amend
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov
, including any personal information you provide. We

will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.

Discussion

    We have received reports indicating that several incidents of bolt
failure at the aft hinge fittings of the thrust reversers have occurred
on certain Boeing Model 757 airplanes equipped with Rolls Royce RB211-
535E engines. Of these incidents, there were nine hinges with failure
of one out of four bolts, two hinges with failure of two out of four
bolts, and three hinges with failure of three out of four bolts. The
possible causes of the bolt failures can be high operational loads,
contact loads caused by possible interference between the thrust
reverser hinge and the hinge beam, or installation of the four
attachment bolts with washers that could rub against the radius of the
hinge fitting spotface. The hinge has integral fail safe features, but
loss of the entire four-bolt pattern constitutes complete loss of the
load path. Failure of the attachment bolts could result in separation
of a thrust reverser from the airplane during flight and consequent
structural damage to the airplane.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletins 757-54-
0049 and 757-54-0050, both dated July 16, 2007. The service information
describes procedures for doing a detailed inspection of the aft hinge
fittings and the eight attachment bolts of the thrust reversers for
signs of damage (includes, but is not limited to, cracked or broken
hinge fittings or contact damage to the base metal), and related
investigative and corrective actions if necessary. The compliance time
for the initial inspection is within 3,000 flight cycles after the date
on the service bulletin.
    The related investigative and corrective actions for the number 1
and number 2 engines include the following:
     For airplanes on which any aft hinge fitting is cracked or
broken: Accomplish the preventive modification specified in Part III of
the Accomplishment Instructions and install a new fitting.
     For airplanes on which any contact damage to the base
metal is found that is less than .005 inch deep: Accomplish the
preventive modification specified in Part III of the Accomplishment
Instructions before further flight; or reapply the surface finish as
specified in Part II of the Accomplishment Instructions (standard
operating procedures manual 20-60-02), and accomplish the preventive
modification within 3,000 flight cycles after the surface finish is
applied.
     For airplanes on which any contact damage to the base
metal is found that is equal to or more than .005 inches deep:
Accomplish the preventive modification as specified in Part III of the
Accomplishment Instructions.
     For airplanes on which any damage is found that is outside
the limits specified in the service information, the service bulletins
recommend contacting Boeing for repair instructions.
     For airplanes on which any attachment bolt is damaged:
Accomplish the preventive modification specified in Part III of the
Accomplishment Instructions, or remove the damaged bolt and accomplish
a high frequency eddy current inspection of the bolt hole for cracking.
If no crack is found in the bolt hole, replace the bolt with a new or
serviceable bolt before further flight and accomplish the preventive
modification within 3,000 flight cycles after the bolt is replaced. If
any crack is found, accomplish the preventive modification.
    For airplanes on which no attachment bolt is found damaged, repeat
the detailed inspection at intervals not to exceed 3,000 flight cycles.
Accomplishing the preventive modification at any time would eliminate
the need for the repetitive inspections.
    Accomplishing the actions specified in the service information is
intended to adequately address the unsafe condition.

Concurrent Service Information

    Service Bulletin 757-54-0049 recommends prior or concurrent
accomplishment of Boeing Service Bulletin 757-54-0015, Revision 3,
dated September 19, 1996. Service Bulletin 757-54-0015 describes
procedures for replacing a certain older hinge fitting and attachment
on airplanes after line number 241.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other airplanes
of this same type design. For this reason, we are proposing this AD,
which would require accomplishing the actions specified in the service
information described previously, except as discussed under
``Difference Between the AD and the Service Information.''

Difference Between the AD and the Service Information

    Although Boeing Special Attention Service Bulletins 757-54-0049 and
757-54-0050 specify that you may contact the manufacturer for repair
instructions, this proposed AD requires you to repair in one of the
following ways:
     Using a method that we approve; or
     Using data that meet the certification basis of the
airplane that have been approved by an Authorized Representative for
the Boeing Delegation

Option Authorization Organization who has been authorized by the FAA to
make those findings.

Costs of Compliance

    There are about 606 airplanes of the affected design in the
worldwide fleet. This proposed AD would affect about 295 airplanes of
U.S. registry. The proposed inspections would take about 2 work hours
per airplane, at an average labor rate of $80 per work hour. Based on
these figures, the estimated cost of the proposed AD for U.S. operators
is $47,200, or $160 per airplane, per inspection cycle.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, Section 106, describes the
authority of the FAA Administrator. Subtitle VII, Aviation Programs,
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701, ``General
requirements.'' Under that section, Congress charges the FAA with
promoting safe flight of civil aircraft in air commerce by prescribing
regulations for practices, methods, and procedures the Administrator
finds necessary for safety in air commerce. This regulation is within
the scope of that authority because it addresses an unsafe condition
that is likely to exist or develop on products identified in this
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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.
    For the reasons discussed above, I certify that the proposed
regulation:
    1. Is not a ``significant regulatory action'' under Executive Order
12866;
    2. Is not a ``significant rule'' under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979); and
    3. Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
    We prepared a regulatory evaluation of the estimated costs to
comply with this proposed AD and placed it in the AD docket. See the
ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by
adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2007-0225; Directorate Identifier 2007-NM-
210-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by January
10, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 757-200, -200CB, -200PF, and
-300 series airplanes, certificated in any category; equipped with
Rolls Royce RB211-535E engines.

Unsafe Condition

    (d) This AD results from reports of several incidents of bolt
failure at the aft hinge fittings of the thrust reversers due to,
among other things, high operational loads. We are issuing this AD
to prevent failure of the attachment bolts and consequent separation
of a thrust reverser from the airplane during flight, which could
result in structural damage to the airplane.

Compliance

    (e) You are responsible for having the actions required by this
AD performed within the compliance times specified, unless the
actions have already been done.

Repetitive Inspections/Investigative and Corrective Actions

    (f) At the time specified in paragraph 1.E. ``Compliance'' of
Boeing Special Attention Service Bulletins 757-54-0049 or 757-54-
0050, both dated July 16, 2007, as applicable, except as provided by
paragraph (g) of this AD: Do a detailed inspection for signs of
damage of the aft hinge fittings and attachment bolts of the thrust
reversers by doing all the actions, including all applicable related
investigative and corrective actions, as specified in the
Accomplishment Instructions of the applicable service bulletin. Do
all applicable related investigative and corrective actions at the
time specified in paragraph 1.E., ``Compliance'' of the applicable
service bulletin. If any damage is found and the service bulletins
specify to contact Boeing for appropriate action: Before further
flight, repair using a method approved in accordance with the
procedures specified in paragraph (j) of this AD.
    (g) Where Boeing Special Attention Service Bulletins 757-54-0049
and 757-54-0050, both dated July 16, 2007, specify compliance times
relative to the date on the service bulletin, this AD requires
compliance within the specified compliance time after the effective
date of this AD.

Concurrent Service Information

    (h) Prior to or concurrently with accomplishing the actions
specified in Boeing Special Attention Service Bulletin 757-54-0049,
dated July 16, 2007, accomplish the replacement specified in Boeing
Service Bulletin 757-54-0015, Revision 3, dated September 19, 1996.
    (i) Actions accomplished before the effective date of this AD in
accordance with Boeing Service Bulletin 757-54-0015, dated February
16, 1989; Revision 1, dated December 20, 1990; or Revision 2, dated
April 21, 1994; are considered acceptable for compliance with the
corresponding actions specified in paragraph (h) of this AD.

Alternative Methods of Compliance (AMOCs)

    (j)(1) The Manager, Seattle Aircraft Certification Office (ACO),
FAA, has the authority to approve AMOCs for this AD, if requested in
accordance with the procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different
compliance time for this AD, follow the procedures in 14 CFR 39.19.
Before using any approved AMOC on any airplane to which the AMOC
applies, notify your appropriate principal inspector (PI) in the FAA
Flight Standards District Office (FSDO), or lacking a PI, your local
FSDO.
    (3) An AMOC that provides an acceptable level of safety may be
used for any repair required by this AD, if it is approved by an
Authorized Representative for the Boeing Commercial Airplanes
Delegation Option Authorization Organization who has been authorized
by the Manager, Seattle ACO, to make those findings. For a repair
method to be approved, the repair must meet the certification basis
of the airplane.

    Issued in Renton, Washington, on November 13, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-22924 Filed 11-23-07; 8:45 am]

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