[Federal Register Volume 64, Number 31 (Wednesday, February 17, 1999)]
[Proposed Rules]
[Pages 7827-7828]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-3735]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-06-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 Boeing Model 757-200
series airplanes. This proposal would require modification of the off-
wing emergency evacuation slide system. This proposal is prompted by
reports that a certain type of off-wing escape slide aboard several
airplanes deployed and separated from the airplane during flight. The
actions specified by the proposed AD are intended to prevent separation
of the emergency evacuation slide from the airplane, which could result
in damage to the fuselage and unavailability of an escape slide during
an emergency evacuation.
DATES: Comments must be received by April 5, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-06-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 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 99-NM-06-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. 99-NM-06-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received reports indicating that in-flight deployment
and separation of the off-wing emergency evacuation slide occurred on
several Boeing Model 757-200 series airplanes. In each of these
incidents, the slide compartment door opened, the slide carrier rotated
out, and the slide deployed. In addition, the deployed slide was torn
off by the airstream and caused damage to the fuselage located aft of
the slide compartment. In one incident, the inboard flaps also were
damaged. These deployments are attributed to the fact that, during
maintenance, the slide compartment door was not properly latched
following replacement of the slide. Further analysis revealed that a
visual inspection of the door latch to verify that the latch is
fastened is difficult; the aft location of the door sensor may not show
that the door is not latched; and incorrect installation of the
lockbase retainer on the door latch tube can prevent locking the door
in the latched position. These conditions, if not corrected, could
result in in-flight deployment and separation of the emergency
evacuation slide from the airplane, damage to the fuselage, and
unavailability of an escape slide during an emergency evacuation.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Service Bulletin 757-25-
0182, Revision 1, dated June 12, 1997; and Boeing Service Bulletin 757-
25-0200, dated January 21, 1999; which describe procedures for
modification of the left and right off-wing emergency evacuation slide
systems.
The modification described in Boeing Service Bulletin 757-25-0182,
Revision 1, includes replacement of the bearings and lockbase retainer
in the compartment door latch assembly with new bearings and a new
lockbase retainer, relocation and adjustment of the sensor target and
the sensor proximity switch to forward locations on the evacuation
slide compartment doors, and a functional test following modification.
The modification described in Boeing Service Bulletin 757-25-0200
includes installation of a bumper assembly on the off-wing slide
carrier and installation of new placards in the area of the maintenance
access door.
Accomplishment of the actions specified in the service bulletins 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 modification of the off-wing emergency
evacuation slide system. The actions would be required to be
accomplished in accordance with the service bulletins described
previously, except as discussed below.
Difference Between Proposed Rule and Service Bulletins
Operators should note that, although the service bulletins
recommend accomplishment of the modification at the next scheduled
maintenance, or as
[[Page 7828]]
soon as manpower and materials are available, the FAA has determined
that an 18-month compliance time would 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 modification. In light of
all of these factors, the FAA finds an 18-month compliance time for
completion of the proposed modification 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 497 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 435 airplanes of U.S. registry
would be affected by this proposed AD.
For airplanes identified in Boeing Service Bulletin 757-25-0182,
Revision 1 (301 U.S.-registered airplanes), it would take approximately
40 work hours per airplane to accomplish the proposed modification of
the door latch system, at an average labor rate of $60 per work hour.
Required parts would cost approximately $1,450 per airplane. Based on
these figures, the cost impact of the proposed modification on U.S.
operators is estimated to be $1,158,850, or $3,850 per airplane.
For airplanes identified in Boeing Service Bulletin 757-25-0200
(435 U.S.-registered airplanes), it would take approximately 4 work
hours to accomplish the proposed installation of the bumper assembly
and placards, at an average labor rate of $60 per work hour. Required
parts would cost approximately $457 per airplane. Based on these
figures, the cost impact of the proposed installation on U.S. operators
is estimated to be $303,195, or $697 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 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 99-NM-06-AD.
Applicability: Model 757-200 series airplanes equipped with off-
wing emergency evacuation slides, as listed in Boeing Service
Bulletin 757-25-0182, Revision 1, dated June 12, 1997, or Boeing
Service Bulletin 757-25-0200, dated January 21, 1999; 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 separation of the emergency evacuation slide from the
airplane, which could result in damage to the fuselage and
unavailability of an escape slide during an emergency evacuation,
accomplish the following:
(a) Within 18 months after the effective date of this AD: Modify
the left and right off-wing emergency evacuation slide systems by
accomplishment of paragraph (a)(1) or (a)(2) of this AD, as
applicable.
(1) For airplanes listed in Boeing Service Bulletin 757-25-0182,
Revision 1, dated June 12, 1997: Modify the door latch system of the
left and right off-wing emergency evacuation slide systems in
accordance with the service bulletin.
Note 2: Modification of the door latch system of the off-wing
emergency evacuation slide system, prior to the effective date of
this AD, in accordance with Boeing Service Bulletin 757-25-0182,
dated October 10, 1996, is considered acceptable for compliance with
paragraph (a)(1) of this AD.
(2) For airplanes listed in Boeing Service Bulletin 757-25-0200,
dated January 21, 1999: Install a bumper assembly on the bottom of
the left and right off-wing escape slide carriers, and install new
placards in the area of the maintenance access door, in accordance
with the service bulletin.
(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 3: 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 February 9, 1999.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-3735 Filed 2-16-99; 8:45 am]
BILLING CODE 4910-13-U
