[Federal Register: April 1, 2004 (Volume 69, Number 63)]
[Proposed Rules]
[Page 17105-17107]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01ap04-29]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2003-NM-166-AD]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757-200, -200PF, and -
200CB Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Boeing Model 757-200, -
200PF, and -200CB series airplanes. This proposal would require an
inspection of certain ballscrews of the trailing edge flap system to
find their part numbers, and replacement of the ballscrews with new,
serviceable, or modified ballscrews if necessary. This action is
necessary to prevent a flap skew due to insufficient secondary load
path of the ballscrew of the trailing edge flaps in the event that the
primary load path fails, which could result in possible loss of a flap
and reduced controllability of the airplane. This action is intended to
address the identified unsafe condition.
DATES: Comments must be received by May 17, 2004.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2003-NM-166-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9 a.m. and 3 p.m., Monday through Friday, except
Federal holidays. Comments may be submitted via fax to (425) 227-1232.
Comments may also be sent via the Internet using the following address:
9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must
contain ``Docket No. 2003-NM-166-AD'' in the subject line and need not
be submitted in triplicate. Comments sent via the Internet as attached
electronic files must be formatted in Microsoft Word 97 or 2000 or
ASCII text.
The service information referenced in the proposed rule may be
obtained from Boeing Commercial Airplanes, 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.
FOR FURTHER INFORMATION CONTACT: Douglas Tsuji, Aerospace Engineer,
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6487; fax (425) 917-6590.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed 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 above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this action may be changed in
light of the comments received.
[[Page 17106]]
Submit comments using the following format:
Organize comments issue-by-issue. For example,
discuss a request to change the compliance time and a request to change
the service bulletin reference as two separate issues.
For each issue, state what specific change to
the proposed AD is being requested.
Include justification (e.g., reasons or data)
for each request.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this action must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 2003-NM-166-AD.'' The postcard will be date stamped
and returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules
Docket No. 2003-NM-166-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received a report from Boeing that certain ballscrews
at positions 1 and 8 of the trailing edge flaps do not have a
sufficient secondary load path on certain Boeing Model 757-200, -200PF,
and -200CB series airplanes. Without a sufficient secondary load path,
the ballnut can slip along the ballscrew if the primary load path
fails. This condition, if not corrected, could result in a flap skew in
the event of failure of the primary load path, which could result in
possible loss of a flap and reduced controllability of the airplane.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
757-27A0139, dated June 16, 2003, which describes procedures for an
inspection of certain ballscrews of the trailing edge flap system to
find their part numbers, and replacement of the ballscrews with new,
serviceable, or modified ballscrews if necessary. Accomplishment of the
actions specified in the service bulletin is intended to adequately
address the identified unsafe condition.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would require accomplishment of the actions specified in
the service bulletin described previously.
Cost Impact
There are approximately 979 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 644 airplanes of U.S. registry
would be affected by this proposed AD.
It would take approximately 1 work hour per airplane to accomplish
the proposed inspection at an average labor rate of $65 per work hour.
Based on these figures, the cost impact of the proposed AD on U.S.
operators is estimated to be $41,860, or $65 per airplane.
Replacement of a ballscrew with a new or serviceable ballscrew, if
required, would take about 3 work hours per ballscrew, at an average
labor rate of $65 per work hour. Required parts would cost about $8,400
per ballscrew. Based on these figures, we estimate the cost of a repair
to be $8,595 per ballscrew (there are two ballscrews per airplane).
Removal, modification, and reinstallation of a ballscrew, if
required, would take about 6 work hours per ballscrew, at an average
labor rate of $65 per work hour. Required parts would cost about $553
per ballscrew. Based on these figures, we estimate the cost of a repair
to be $943 per ballscrew (there are two ballscrews per airplane).
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the proposed requirements
of this AD action, and that no operator would accomplish those actions
in the future if this proposed AD were not adopted. The cost impact
figures discussed in AD rulemaking actions represent only the time
necessary to perform the specific actions actually required by the AD.
These figures typically do not include incidental costs, such as the
time required to gain access and close up, planning time, or time
necessitated by other administrative actions.
Regulatory Impact
The regulations proposed herein 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. Therefore, it
is determined that this proposal would not have federalism implications
under Executive Order 13132.
For the reasons discussed above, I certify that 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) if promulgated, 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. A copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Boeing: Docket 2003-NM-166-AD.
Applicability: Model 757-200, -200PF, and -200CB series
airplanes, line numbers 1 through 979 inclusive; certificated in any
category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent a flap skew due to insufficient secondary load path
of the ballscrew of the trailing edge flaps in the event that the
primary load path fails, which could result in possible loss of a
flap and reduced controllability of the airplane, accomplish the
following:
Inspection and Corrective Action
(a) Within 36 months after the effective date of this AD, do an
inspection of the ballscrews of the trailing edge flap system to
find their part numbers (P/N) per the Accomplishment Instructions of
Boeing Alert Service Bulletin 757-27A0139, dated June
[[Page 17107]]
16, 2003. If the P/N of the ballscrew is S251N401-5 (Thomson Saginaw
P/N 7820921) or S251N401-9 (Thomson Saginaw P/N 7821341), within 36
months after the effective date of this AD, replace the ballscrew
with a new, serviceable, or modified ballscrew per the service
bulletin.
Parts Installation
(b) As of the effective date of this AD, no person may install a
trailing edge flap ballscrew, P/N S251N401-5 or -9, on any airplane.
Alternative Methods of Compliance
(c) In accordance with 14 CFR 39.19, the Manager, Seattle
Aircraft Certification Office, FAA, is authorized to approve
alternative methods of compliance for this AD.
Issued in Renton, Washington, on March 24, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-7295 Filed 3-31-04; 8:45 am]
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