[Federal Register Volume 59, Number 45 (Tuesday, March 8, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-5241]


[[Page Unknown]]

[Federal Register: March 8, 1994]


                                                    VOL. 59, NO. 45

                                             Tuesday, March 8, 1994
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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-03-AD]

 

Airworthiness Directives; Boeing Model 757 and 767 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 and 767 
series airplanes. This proposal would require modification of the latch 
hook installation for the number two cockpit window frame. This 
proposal is prompted by reports of the flight crew executing rejected 
takeoffs (RTO) and air turnbacks (ATB) due to false ``closed'' 
indications for the number two cockpit window. The actions specified by 
the proposed AD are intended to prevent unlatched (not completely 
closed) number two cockpit windows and the resultant execution of RTO's 
and ATB's by the flight crew.

DATES: Comments must be received by May 2, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-03-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.
    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: Roy Boffo, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (206) 227-2780; fax (206) 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 notice may be changed in 
light of the comments received.
    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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 94-NM-03-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-103, Attention: Rules 
Docket No. 94-NM-03-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056

Discussion

    Recently, the FAA has received several reports from an operator of 
Boeing Model 757-200 series airplanes that the flight crew executed 
rejected takeoffs (RTO) due to the number two cockpit window failing to 
close completely. In two of these incidents, the RTO's were initiated 
at 120 knots. As a result, this operator developed special procedures 
to ensure that these windows were latched prior to each flight. 
However, these procedures proved to be ineffective, as evidenced by the 
subsequent execution of four additional RTO's.
    Further, several operators of Boeing Model 767 series airplanes 
recently reported that the flight crew executed air turnbacks (ATB) due 
to false ``closed'' indications for the number two cockpit window. 
Although the latch indicator showed ``closed,'' the number two cockpit 
window was not completely latched, which resulted in noise in the 
cockpit.
    Investigation into the cause of these unlatched windows revealed 
that, although the latch handle, which operates a flexible cable that 
moves four latch cams on the upper, lower, and aft edges of the window 
frame, may be moved to the ``latched'' (closed) position, the latch 
cams may not fully engage the latch posts.
    The latch handles must be in the ``unlatched'' (opened) position to 
permit the window to travel to the fully closed position. By rotating 
the latch handle 180 degrees to the ``latched'' position, the latch 
cams on the window frame should engage the latch stud on the body of 
the window frame to prevent the window from opening and to lock the 
window closed. If the windows do not close completely, cabin 
pressurization and speed limits will be adversely affected during RTO's 
and ATB's.
    This condition, if not corrected, could result in the flight crew 
executing RTO's and ATB's due to unlatched (not completely closed) 
number two cockpit windows.
    The FAA has reviewed and approved Boeing Service Bulletin 757-56-
0007, dated May 6, 1993 (for Model 757 series airplanes), and Boeing 
Service Bulletin 767-56-002, dated August 30, 1985, as amended by 
Notice of Status Change (NSC) Number 767-56-0002 NSC 1, dated July 3, 
1986 (for Model 767 series airplanes), that describe procedures for 
modification of the latch hook installation for the number two cockpit 
window frame. This modification entails adding a cam latch hook to the 
window frame; removing a bolt and nut from the window post; and 
installing a bolt, spacer, and nut on the window post to strike and 
move the latch hook away from the latch cam when the window is closed. 
(The number two cockpit window on the Model 757 and 767 series 
airplanes are similar in design.)
    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 modification of the latch hook installation 
for the number two cockpit window frame. The actions would be required 
to be accomplished in accordance with the applicable service bulletin 
and NSC described previously.
    There are approximately 640 Model 757 and 767 series airplanes of 
the affected design in the worldwide fleet. The FAA estimates that 409 
airplanes of U.S. registry would be affected by this proposed AD, that 
it would take approximately 8 work hours per airplane to accomplish the 
proposed actions, and that the average labor rate is $55 per work hour. 
Required parts would cost approximately $2,000 per airplane. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $997,960, or $2,440 per airplane.
    The total 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 AD were not adopted.
    The regulations proposed herein would not have substantial direct 
effects 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, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    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 14 
CFR part 39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:


    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Boeing: Docket 94-NM-03-AD.

    Applicability: Model 757 series airplanes having line positions 
1 through 534 inclusive, and Model 767 series airplanes having line 
positions 1 through 114 inclusive; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent unlatched (not completely closed) number two cockpit 
windows and the resultant execution of rejected takeoffs and air 
turnbacks by the flight crew, accomplish the following: (a) Within 
18 months after the effective date of this AD, modify the latch hook 
installation for the number two cockpit window frame in accordance 
with Boeing Service Bulletin 757-56-0007, dated May 6, 1993 (for 
Model 757 series airplanes); or Boeing Service Bulletin 767-56-0002, 
dated August 30, 1985, as amended by Notice of Status Change Number 
767-56-0002 NSC 1, dated July 3, 1986 (for Model 767 series 
airplanes); as applicable.
    (b) 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, Transport Airplane Directorate. 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: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

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

    Issued in Renton, Washington, on March 2, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-5241 Filed 03-07-94; 8:45 am]
BILLING CODE 4910-13-U