
[Federal Register: May 20, 2008 (Volume 73, Number 98)]
[Proposed Rules]               
[Page 29087-29089]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20my08-14]                         


[[Page 29087]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0561; Directorate Identifier 2007-NM-223-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 757-200 and -200PF Series 
Airplanes, and Model 767-200 and -300 Series Airplanes

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 757-200 and -200PF series airplanes; and Model 
767-200 and -300 series airplanes. This proposed AD would require doing 
an inspection to determine the part number and serial number of the hub 
assembly of the ram air turbine (RAT), and replacing the hub assembly 
of the RAT with a new, serviceable, or reworked and re-identified hub 
assembly if necessary. This proposed AD results from reports indicating 
that the counterweights in some hub assemblies of the RATs could be 
under strength and fracture when they are extended in flight. We are 
proposing this AD to prevent a fractured counterweight on the hub 
assembly of the RAT, which will cause an overspeed condition, and 
consequent turbine blade separation, possible injury to passengers, 
possible airplane structural damage, and an inoperative RAT. An 
inoperative RAT will cause the loss of hydraulic power to the primary 
flight controls in cases where both engines are shut down in flight, 
resulting in subsequent loss of control of the airplane.

DATES: We must receive comments on this proposed AD by July 7, 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: 202-493-2251.
     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 800-647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

FOR FURTHER INFORMATION CONTACT: Kenneth Frey, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 917-6468; fax (425) 917-6590.

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-2008-0561; 
Directorate Identifier 2007-NM-223-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 the counterweights in some 
hub assemblies of the ram air turbine (RAT) could be under strength and 
fracture when they are extended in flight, on certain Boeing Model 757-
200 and -200PF series airplanes and Model 767-200 and -300 series 
airplanes. The cause of the fractures has been attributed to a 
manufacturing process error. A fractured counterweight on the hub 
assembly of the RAT, if not corrected, will cause an overspeed 
condition, and consequent turbine blade separation, possible injury to 
passengers, possible airplane structural damage, and an inoperative 
RAT. An inoperative RAT will cause the loss of hydraulic power to the 
primary flight controls in cases where both engines are shut down in 
flight, resulting in subsequent loss of control of the airplane.

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 757-29A0066, dated 
January 2, 2007 (for Model 757-200 and -200PF series airplanes); and 
Boeing Alert Service Bulletin 767-29A0110, dated January 2, 2007 (for 
Model 767-200 and -300 series airplanes). The service bulletins 
describe procedures for doing an inspection to determine the part 
number and serial number on the hub assembly of the RAT, replacing the 
hub assembly of the RAT with a new, serviceable, or reworked and re-
identified hub assembly if necessary, and submitting a report to the 
manufacturer. Accomplishing the actions specified in the service 
information is intended to adequately address the unsafe condition.
    Boeing Alert Service Bulletin 757-29A0066, refers to the Hamilton 
Sundstrand Service Bulletin 730814-29-12, dated November 30, 2005; and 
Boeing Alert Service Bulletin 767-29A0110, refers to the Hamilton 
Sundstrand Service Bulletin 729548-29-15, dated November 30, 2005; as 
additional sources of service information for accomplishing the 
inspection and replacement of the hub assembly of the RAT.

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 Boeing 
service information described previously, except as discussed under 
``Difference between the Proposed Rule and Referenced Service 
Bulletin.''

Difference Between Proposed Rule and Referenced Service Bulletin

    Operators should note that, although the Accomplishment 
Instructions of the referenced Boeing service bulletins describe 
procedures for submitting a feedback form related to the service 
bulletins, this proposed AD would not require those actions.

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Costs of Compliance

    There are about 60 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 43 airplanes of 
U.S. registry. The proposed inspection would take about 1 work hour 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 
$3,440, or $80 per airplane.

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-2008-0561; Directorate Identifier 2007-NM-
223-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by July 7, 
2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing airplanes identified in Table 1 of 
this AD, certified in any category.

                         Table 1.--Applicability
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              For model--                       As identified in--
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(1) 757-200 and -200PF series airplanes  Boeing Alert Service Bulletin
                                          757-29A0066, dated January 2,
                                          2007.
(2) 767-200 and -300 series airplanes..  Boeing Alert Service Bulletin
                                          767-29A0110, dated January 2,
                                          2007.
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Unsafe Condition

    (d) This AD results from reports indicating that the 
counterweights in some hub assemblies of the ram air turbines (RAT) 
could be under strength and fracture when they are extended in 
flight. We are issuing this AD to prevent a fractured counterweight 
on the hub assembly of the RAT, which will cause an overspeed 
condition, and consequent turbine blade separation, possible injury 
to passengers, possible airplane structural damage, and an 
inoperative RAT. An inoperative RAT will cause the loss of hydraulic 
power to the primary flight controls in cases where both engines are 
shut down in flight, resulting in subsequent loss of control of 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.

Inspection and Replacement

    (f) Within 24 months after the effective date of this AD, do an 
inspection to determine the part number and serial number on the hub 
assembly of the RAT in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 757-29A0066, dated 
January 2, 2007 (for Model 757-200 and -200PF series airplanes); or 
Boeing Alert Service Bulletin 767-29A0110, dated January 2, 2007 
(for Model 767-200 and -300 series airplanes); as applicable. If the 
part number and serial number on the hub assembly of the RAT are 
listed in Table 2 of this AD, within 24 months after the effective 
date of this AD, replace the hub assembly of the RAT with a new, 
serviceable, or reworked and re-identified hub assembly, in 
accordance with the Accomplishment Instructions of the service 
bulletin.

Parts Installation

    (g) As of the effective date of this AD, no person may install a 
hub assembly of the RAT having any applicable part number and serial 
number listed in Table 2 of this AD, on any airplane, unless it has 
been reworked and re-identified in accordance with paragraph (f) of 
this AD.

                 Table 2.--RAT Hub Assembly Part Numbers
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           For model--                Part No.--         Serial No.--
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(1) 757-200 and -200PF series     733785A or 733785B  0410 through 0413
 airplanes.                                            inclusive, 0415,
                                                       0417 through
                                                       0430, 0432, or
                                                       0434.
(2) 767-200 and -300 series       734350A, 734350B,   0666, 0673 through
 airplanes.                        734350C, or         0684 inclusive,
                                   734350D.            0686, 0687, or
                                                       0689.
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No Information Submission

    (h) Although Boeing Alert Service Bulletin 757-29A0066, dated 
January 2, 2007 (for Model 757-200 and -200PF series airplanes); and 
Boeing Alert Service Bulletin 767-29A0110, dated January 2, 2007 
(for Model 767-200 and -300 series airplanes); specify to submit 
information to the manufacturer, this AD does not include that 
requirement.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Seattle Aircraft Certification Office, 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.

    Issued in Renton, Washington, on May 7, 2008.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-11286 Filed 5-19-08; 8:45 am]

BILLING CODE 4910-13-P
