[Federal Register Volume 63, Number 242 (Thursday, December 17, 1998)]
[Proposed Rules]
[Pages 69569-69571]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-33391]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-238-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757-200 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 757-200 series airplanes. 
This proposal would require replacement of the stringer clip(s) with a 
new stringer clip(s), and modification of the life raft support 
structure and/or life raft doors, as applicable. This proposal is 
prompted by a report that certain life raft stowage compartments and 
certain life raft doors are understrength. The actions specified by the 
proposed AD are intended to prevent a life raft falling from its 
stowage compartment, and consequently injuring nearby occupants or 
delaying or impeding the evacuation of passengers during an emergency 
landing.

DATES: Comments must be received by February 1, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-238-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 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: Keith Ladderud, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2780; 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 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

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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 98-NM-238-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. 98-NM-238-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report that certain life raft stowage 
compartments and certain life raft doors are understrength on Boeing 
Model 757-200 series airplanes. Analysis and testing has shown that, 
under certain loading conditions during an emergency landing, the 
structure of the life raft stowage compartment could fail, and/or the 
doors of these compartments could break from their hinges. 
Investigation has revealed that the existing design of the life raft 
stowage compartments is inadequate to carry the load, and that certain 
life raft doors were not manufactured to the proper specifications. 
These conditions, if not corrected, could result in a life raft falling 
from its stowage compartment, and consequently injuring nearby 
occupants or delaying or impeding the evacuation of passengers during 
an emergency landing.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 757-25-
0180, dated October 9, 1997, which describes procedures for replacement 
of the stringer clip(s) with a new stringer clip(s), and modification 
of the life raft support structure and/or life raft doors, as 
applicable. The modification involves installation of doublers, 
channels, tie rod and radius blocks, and brackets, as applicable. 
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.

Differences Between Proposed Rule and Service Bulletin

    Operators should note that, although the service bulletin 
recommends that the replacement and modication be accomplished at the 
first maintenance opportunity, the FAA has determined that such an 
unspecified interval may not address the identified unsafe condition in 
a timely manner. In developing an appropriate compliance time for this 
AD, the FAA considered not only the manufacturer's recommendation, but 
the degree of urgency associated with addressing the subject unsafe 
condition, the average utilization of the affected fleet, and the time 
necessary to perform the proposed actions. In light of all of these 
factors, the FAA finds an 18-month compliance time for accomplishing 
the proposed actions to be warranted, in that it represents an 
appropriate interval of time allowable for affected airplanes to 
continue to operate without compromising safety.

Cost Impact

    There are approximately 256 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 139 airplanes of U.S. registry 
would be affected by this proposed AD.
    For Groups 1 and 2 airplanes (as specified in the service 
bulletin), it would take approximately 32 work hours per airplane to 
accomplish the proposed actions, at an average labor rate of $60 per 
work hour. Required parts would cost approximately $4,544 (for Group 1 
airplanes) or $4,801 (for Group 2 airplanes) per airplane. Based on 
these figures, the cost impact of the actions proposed by this AD on 
U.S. operators of Groups 1 and 2 airplanes is estimated to be $6,464 
(for Group 1 airplanes), or $6,721 (for Group 2 airplanes) per 
airplane.
    For Groups 3 and 4 airplanes, it would take approximately 30 work 
hours per airplane to accomplish the proposed actions, at an average 
labor rate of $60 per work hour. Required parts would cost 
approximately $3,668 (for Group 3 airplanes) or $3,530 (for Group 4 
airplanes) per airplane. Based on these figures, the cost impact of the 
actions proposed by this AD on U.S. operators of Groups 3 and 4 
airplanes is estimated to be $5,468 (for Group 3 airplanes), or $5,330 
(for Group 4 airplanes) per airplane.
    For Group 5 airplanes, it would take approximately 6 work hours per 
airplane to accomplish the proposed actions, at an average labor rate 
of $60 per work hour. Required parts would cost approximately $680 per 
airplane. Based on these figures, the cost impact of the actions 
proposed by this AD on this group of U.S. operators is estimated to be 
$1,040 per airplane.
    For Group 6 airplanes, it would take approximately 20 work hours 
per airplane to accomplish the proposed actions, at an average labor 
rate of $60 per work hour. Required parts would cost approximately 
$2,785 per airplane. Based on these figures, the cost impact of the 
actions proposed by this AD on this group of U.S. operators is 
estimated to be $3,985 per airplane.
    For Group 7 airplanes, it would take approximately 13 work hours 
per airplane to accomplish the proposed actions, at an average labor 
rate of $60 per work hour. Required parts would cost approximately 
$1,019 per airplane. Based on these figures, the cost impact of the 
actions proposed by this AD on this group of U.S. operators is 
estimated to be $1,799 per airplane.
    For Group 8 airplanes, it would take approximately 15 work hours 
per airplane to accomplish the proposed actions, at an average labor 
rate of $60 per work hour. Required parts would cost approximately 
$2,187 per airplane. Based on these figures, the cost impact of the 
actions proposed by this AD on this group of U.S. operators is 
estimated to be $3,087 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 AD were not adopted.

Regulatory Impact

    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

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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 98-NM-238-AD.

    Applicability: Model 757-200 series airplanes, as listed in 
Boeing Service Bulletin 747-25-0180, dated October 9, 1997; 
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 (b) 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 life raft from falling from its stowage 
compartment, and consequently injuring nearby occupants or delaying 
or impeding the evacuation of passengers during an emergency 
landing, accomplish the following:
    (a) Within 18 months after the effective date of this AD, 
replace the stringer clip(s) with a new stringer clip(s), and modify 
the life raft support structure and/or life raft door, as 
applicable, in accordance with Boeing Service Bulletin 757-25-0180, 
dated October 9, 1997.
    (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 2: 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 
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.

    Issued in Renton, Washington, on December 11, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-33391 Filed 12-16-98; 8:45 am]
BILLING CODE 4910-13-U