[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]
BILLING CODE 4910-13-P