[Federal Register Volume 66, Number 94 (Tuesday, May 15, 2001)]
[Proposed Rules]
[Pages 26819-26822]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-12174]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-405-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757 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 series 
airplanes. This proposal would require an inspection to determine the 
serial numbers of geared rotary actuators (GRA) for the leading edge 
slats, and replacement of certain actuators with new or reworked 
actuators. This action is necessary to prevent a fractured spring 
washer in a GRA, which could lead to a disconnect in the GRA, and 
result in a slat skew condition and consequent reduced controllability 
of the airplane. This action is intended to address the identified 
unsafe condition.

[[Page 26820]]


DATES: Comments must be received by June 29, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2000-NM-405-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: 
<a href="/cdn-cgi/l/email-protection#ffc6d29e9192d2918f8d929c9092929a918bbf999e9ed1989089"><span class="__cf_email__" data-cfemail="c6ffeba7a8abeba8b6b4aba5a9ababa3a8b286a0a7a7e8a1a9b0">[email protected]</span></a>. Comments sent via fax or the Internet must 
contain ``Docket No. 2000-NM-405-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 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Boeing Commercial Airplane Group, 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: Barbara Mudrovich, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2983; fax (425) 227-1181.

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.
    Submit comments using the following format:
    <bullet> 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.
    <bullet> For each issue, state what specific change to the proposed 
AD is being requested.
    <bullet> 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 2000-NM-405-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. 2000-NM-405-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received reports indicating that certain geared rotary 
actuators (GRA) for the leading edge slats on certain Boeing Model 757 
series airplanes have been assembled with discrepant spring washers. 
The discrepant spring washers were not adequately processed during the 
phase of manufacture in which cadmium plating is applied. A fractured 
spring washer could lead to a disconnect between the input shaft or 
input plate and the output plate or splined gearshaft, which could 
result in a skew condition for the leading edge slat if one of the two 
actuators on each slat continues to drive the slat. The serial numbers 
of all affected GRAs are known.
    Certain airplanes have had an enhanced slat skew or loss detection 
system installed either during production or according to Boeing 
Service Bulletin 757-27-0126, dated May 11, 2000. For these airplanes, 
a slat skew condition is not an airworthiness concern.
    However, for airplanes without an enhanced slat skew or loss 
detection system, a slat skew condition, if not detected by the flight 
crew, could result in reduced controllability of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Alert Service Bulletins 
757-27A0133 (for Model 757-200, 757-200CB, and 757-200PF series 
airplanes) and 757-27A0134 (for Model 757-300 series airplanes), both 
dated October 11, 2000. Those service bulletins describe procedures for 
a one-time inspection to determine the serial numbers of GRAs for the 
leading edge slats. If GRAs with certain serial numbers are installed, 
the service bulletin describes procedures for replacing affected GRAs 
with new or reworked parts. Accomplishment of the actions specified in 
the applicable service bulletin is intended to adequately address the 
identified unsafe condition.
    The Boeing service bulletins refer to Hamilton Sundstrand Service 
Bulletins 5006397/755299-27-21 and 5006398/755300-27-21, both dated 
January 24, 2000, as sources for the identification of affected part 
numbers and serial numbers, as well as instructions for reworking 
affected GRAs.

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 applicable Boeing service bulletin described previously.

Explanation of Applicability

    While only certain Boeing Model 757 series airplanes had the GRAs 
with the discrepant spring washers installed in production, it is 
possible that the affected GRAs have been installed as spares on other 
Boeing Model 757 series airplanes. Therefore, the FAA finds that the 
unsafe condition addressed by this proposed AD may occur on any Boeing 
Model 757 series airplane manufactured on or prior to the effective 
date of this AD. However, paragraph (d) of this AD prohibits 
installation of the affected parts after the effective date of this AD; 
thus, airplanes with a date of manufacture after the effective date of 
this AD would not be subject to this proposed AD.

Cost Impact

    There are approximately 950 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 606 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
20 work hours per airplane to accomplish the proposed inspection, and 
that the average labor rate is $60 per work hour. Based on these 
figures, the cost impact of the proposed AD on U.S. operators is 
estimated to be $727,200, or $1,200 per airplane.

[[Page 26821]]

    The cost impact figure discussed above is 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.
    Should an operator be required to accomplish the replacement of all 
GRAs on an airplane, it would take approximately 30 work hours per 
airplane (1.5 work hours per actuator), at an average labor rate of $60 
per work hour. Required parts may be provided by the parts manufacturer 
at no cost to the operator. Based on these figures, the cost impact of 
the proposed replacement is estimated to be up to $1,800 per airplane.

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 2000-NM-405-AD.

    Applicability: Model 757 series airplanes with a date of 
manufacture that is on or before the effective date of this AD, 
certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (e) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent a fractured spring washer in a geared rotary actuator 
(GRA) for the leading edge slats, which could lead to a disconnect 
in the GRA, and result in a slat skew condition and consequent 
reduced controllability of the airplane, accomplish the following:

Inspection To Determine Serial Numbers

    (a) At the applicable compliance time specified in paragraph 
(a)(1) or (a)(2) of this AD, inspect the 20 geared rotary actuators 
(GRA) for the leading edge slats to determine the part number series 
and serial number for each GRA, according to Boeing Alert Service 
Bulletin 757-27A0133 (for Model 757-200, 757-200CB, and 757-200PF 
series airplanes), or 757-27A0134 (for Model 757-300 series 
airplanes), both dated October 11, 2000; as applicable.
    (1) For Boeing 757-200 series airplanes with line numbers (L/N) 
1 through 803, on which an enhanced slat skew or loss detection 
system has NOT been installed according to Boeing Service Bulletin 
757-27-0126, dated May 11, 2000, or Boeing Production Revision 
Record 54755: Do the inspection within 18 months after the effective 
date of this AD.
    (2) For airplanes other than those identified in paragraph 
(a)(1) of this AD: Do the inspection within 36 months after the 
effective date of this AD.

If No Subject GRA Is Installed--No Further Action

    (b) If no GRA has a part number series and serial number listed 
under Section 1.A. of Hamilton Sundstrand Service Bulletins 5006397/
755299-27-21 or 5006398/755300-27-21, both dated January 24, 2000: 
No further action is required by this AD.

If Any Subject GRAs Are Installed--Corrective Actions

    (c) For any GRA with a part number series and serial number 
listed under Section 1.A. of Hamilton Sundstrand Service Bulletins 
5006397/755299-27-21 or 5006398/755300-27-21, both dated January 24, 
2000: At the applicable compliance time specified in paragraph 
(c)(1) or (c)(2) of this AD, replace the subject GRA with a new or 
reworked GRA, according to Boeing Alert Service Bulletin 757-27A0133 
(for Model 757-200, 757-200CB, and 757-200PF series airplanes), or 
757-27A0134 (for Model 757-300 series airplanes), both dated October 
11, 2000; as applicable.
    (1) For Boeing 757-200 series airplanes with line numbers (L/N) 
1 through 803, on which an enhanced slat skew or loss detection 
system has NOT been installed according to Boeing Service Bulletin 
757-27-0126, dated May 11, 2000, or Boeing Production Revision 
Record 54755: Replace any subject GRA within 18 months after the 
effective date of this AD.
    (2) For airplanes other than those identified in paragraph 
(c)(1) of this AD: Replace any subject GRA within 36 months after 
the effective date of this AD.

Spares

    (d) After the effective date of this AD, no one may install a 
GRA that has a part number series and serial number listed under 
Section 1.A. of Hamilton Sundstrand Service Bulletins 5006397/
755299-27-21 or 5006398/755300-27-21, both dated January 24, 2000, 
on any airplane.

Alternative Methods of Compliance

    (e) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Seattle ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (f) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.


[[Page 26822]]


    Issued in Renton, Washington, on May 9, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-12174 Filed 5-14-01; 8:45 am]
BILLING CODE 4910-13-P


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