[Federal Register Volume 69, Number 63 (Thursday, April 1, 2004)]
[Proposed Rules]
[Pages 17105-17107]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-7295]


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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: 
[email protected]. 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]
BILLING CODE 4910-13-P