[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
[[Page 69570]]
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
[[Page 69571]]
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