Document ID: FAA-2008-0295-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Boeing Model 757 Airplanes
Posted Date: 2008-03-13T04:00Z

[Federal Register: March 13, 2008 (Volume 73, Number 50)]
[Proposed Rules]               
[Page 13492-13494]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13mr08-17]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0295; Directorate Identifier 2007-NM-298-AD]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 757 Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
Boeing Model 757-200, -200PF, -200CB, and -300 series airplanes. This 
proposed AD would require an inspection of the two spring arms in the 
spin brake assemblies in the nose wheel well to determine if the spring 
arms are made of aluminum or composite material, and repetitive related 
investigative/corrective actions if necessary. This proposed AD results 
from reports of cracked and broken aluminum spring arms. We are 
proposing this AD to detect and correct cracked or broken spring arms. 
A cracked or broken spring arm could separate from the airplane and 
result in potential hazard to persons or property on the ground, or 
ingestion into the engine with engine damage and potential shutdown, or 
damage to the airplane.

DATES: We must receive comments on this proposed AD by April 28, 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: Jason Deutschman, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 
917-6449; 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-2008-0295; 
Directorate Identifier 2007-NM-298-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

    Two spin brake assemblies are installed in the nose wheel well and 
include the spin brake spring arms. Wear bars or brake pads installed 
on the spin brake spring arms bring the nose wheel to a stop after the 
gear is retracted. We have received reports of cracked and broken 
aluminum spring arms. In some cases, the aluminum spin brake spring arm 
separated from the airplane. Cracked or broken spring arms, if not 
detected and corrected, could

[[Page 13493]]

separate from the airplane and result in potential hazard to persons or 
property on the ground, or ingestion into the engine with engine damage 
and potential shutdown, or damage to the airplane.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 757-32-
0176, dated September 10, 2007. The service bulletin describes 
procedures for an inspection of the two spring arms in the spin brake 
assemblies in the nose wheel well to determine if the spring arms are 
made of aluminum or composite material. The compliance time for 
determining the material of the spring arm is before the accumulation 
of 6,000 total flight cycles on the spring arm, or within 300 flight 
cycles, whichever occurs later.
    For any aluminum spin arm, the service bulletin describes 
procedures for related investigative/corrective actions. The related 
investigative actions include repetitive detailed and high frequency 
eddy current inspections for cracking of the aluminum spring arm. The 
compliance time for doing the first detailed inspection is before the 
accumulation of 6,000 total flight cycles on the spin arm; or within 
300 flight cycles, whichever occurs later. The repetitive interval for 
the detailed inspection is 300 flight cycles. The compliance time for 
doing the first high frequency eddy current inspection is before the 
accumulation of 6,000 total flight cycles on the spin arm; or within 
1,500 flight cycles, whichever occurs later. The repetitive interval 
for the high frequency eddy current inspection is 1,500 flight cycles.
    The corrective action if any crack is found on an aluminum spring 
arm is replacing the spring arm with a new spring arm made of either 
aluminum or composite material. The service bulletin states that the 
replacement is to be done before further flight, except that the 
airplane can be operated for 10 calendar days with the spin brake 
spring arms removed provided the airplane is operated within the 
restrictions given in the Boeing Model 757 Master Minimum Equipment 
List (MMEL).
    The service bulletin also specifies that replacing an aluminum 
spring arm with a spring arm made of composite material ends the need 
for the repetitive inspections.

FAA's Determination and Requirements of This Proposed AD

    We are proposing this AD because we evaluated all relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design. 
This proposed AD would require accomplishing the actions specified in 
the service information described previously.

Interim Action

    The service bulletin indicates that the design for the spring arm 
was changed from composite to aluminum due to reports of excessive 
noise related to the spring arm made of composite material. Boeing is 
currently developing a kit to replace the aluminum spring arm with a 
new part made from corrosion resistant steel (CRES). Once the CRES 
spring arm is developed, approved, and available, the FAA might 
consider additional rulemaking. However, the spring arm made of 
composite material is adequate to ensure continued operational safety 
of the airplane.

Costs of Compliance

    We estimate that this proposed AD would affect 668 airplanes of 
U.S. registry. We also estimate that it would take about 1 work-hour 
per product to comply with this proposed AD. The average labor rate is 
$80 per work-hour. Based on these figures, we estimate the cost of this 
proposed AD to the U.S. operators to be $53,440, or $80 per product.

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 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 this 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.
    You can find our regulatory evaluation and the estimated costs of 
compliance in the AD Docket.

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 FAA amends Sec.  39.13 by adding the following new AD:

Boeing: Docket No. FAA-2008-0295; Directorate Identifier 2007-NM-
298-AD.

Comments Due Date

    (a) We must receive comments by April 28, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Boeing Model 757-200, -200PF, -200CB, 
and -300 series airplanes, certificated in any category.

Unsafe Condition

    (d) This AD results from reports of cracked and broken aluminum 
spring arms. We are issuing this AD to detect and correct cracked or 
broken spring arms. A cracked or broken spring arm could separate 
from the airplane and result in potential hazard to persons or 
property on the ground, or ingestion into the engine with engine 
damage and potential shut down, or damage to the airplane.

Compliance

    (e) Comply with this AD within the compliance times specified, 
unless already done.

Inspections and Corrective Actions

    (f) At the applicable time specified in paragraph 1.E., 
``Compliance,'' of Boeing Special Attention Service Bulletin 757-32-

[[Page 13494]]

0176, dated September 10, 2007, do a general visual inspection to 
determine the material (aluminum or composite) of the two spring 
arms in the spin brake assemblies in the nose wheel well. A review 
of airplane maintenance records is acceptable in lieu of this 
inspection if the material can be conclusively determined from that 
review. Do all applicable related investigative and corrective 
actions, and all repetitive inspections thereafter, at the 
applicable time specified in paragraph 1.E., ``Compliance,'' of the 
service bulletin. Do all actions in accordance with the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 757-32-0176, dated September 10, 2007, except, where the 
service bulletin specifies a compliance time after the date on the 
service bulletin, this AD requires compliance within the specified 
compliance time after the effective date of this AD.

Optional Terminating Action

    (g) Replacing an aluminum spring arm with a spring arm made of 
composite material in accordance with Figure 5 of Boeing Special 
Attention Service Bulletin 757-32-0176, dated September 10, 2007, 
ends the repetitive inspections required by paragraph (f) of this AD 
for that spring arm.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Seattle Aircraft Certification Office (ACO), 
FAA, ATTN: Jason Deutschman, Aerospace Engineer, Airframe Branch, 
ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind 
Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-
6449; fax (425) 917-6590; has the authority to approve AMOCs for 
this AD, if requested using 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, and the approval must specifically refer to this 
AD.

    Issued in Renton, Washington, on March 3, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E8-5014 Filed 3-12-08; 8:45 am]

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