[Federal Register Volume 64, Number 229 (Tuesday, November 30, 1999)]
[Rules and Regulations]
[Pages 66754-66756]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-30628]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-89-AD; Amendment 39-11435; AD 99-24-11]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 757-200 and -300 Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Boeing Model 757-200 and -300 series airplanes,
that requires modification of the slide/raft evacuation system by
installing a girt reinforcement chafing patch. This amendment is
prompted by reports of holes in the inflatable area of the slide/raft
evacuation system due to chafing against the installation support
bracket. The actions specified by this AD are intended to prevent holes
in the inflatable portion of the slide/raft evacuation system, which
could result in the slide/raft being less effective as a raft during an
emergency water landing.
DATES: Effective January 4, 2000.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of January 4, 2000.
ADDRESSES: The service information referenced in this AD may be
obtained from Air Cruisers Company, Technical Publications Department,
P.O. Box 180, Belmar, New Jersey 07719-0180. This information may be
examined at the Federal Aviation Administration (FAA), Transport
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton,
Washington; or at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC.
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: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain Boeing Model 757-200 and -
300 series airplanes was published in the Federal Register on July 20,
1999 (64 FR 38846). That action proposed to require modification of the
slide/raft evacuation system by installing a girt reinforcement chafing
patch.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Support for the Proposal
Two commenters support the proposed rule. One commenter states that
it is not affected by the proposed rule because its airplanes are not
equipped with the slide/rafts referenced in the proposal. Another
commenter states that it is in the process of accomplishing the actions
specified by Air Cruisers Company Service Bulletin 757-105-25-51, dated
January 29, 1999.
Request To Revise the Unsafe Condition
One commenter suggests that the unsafe condition cited in the
notice of proposed rulemaking (NPRM) be revised to state that holes
caused by the slide/raft chafing on the harness bracket could result in
the slide/raft being ``less effective'' as a raft during an emergency
water landing rather than ``unusable.'' The commenter contends that the
escape slide/rafts are designed with two independent inflation
chambers. Each independent chamber is capable of supporting the rated
occupancy of the slide/raft, and there have been no reports of holes in
both chambers.
The FAA concurs with the commenter's statement that the holes
caused by the slide/raft chafing against the bracket could result in
the slide/raft being ``less effective'' rather than ``unusable.'' Based
on reports that only one chamber of the slide/raft would be affected,
the FAA has determined that this change is appropriate and has changed
the final rule accordingly.
Request To Add an Inspection Requirement
One commenter states that an immediate inspection of the slide/
rafts is required to ensure that any slide/raft already chafed ``to the
point of failure'' be repaired immediately.
The FAA does not concur that an immediate inspection of the slide/
rafts is necessary. To date, the FAA has received only two reports of
chafing/scuffing of the slide/rafts that have resulted in a small hole
being worn through one of the two inflatable chambers. The FAA adds
that such a condition would result in a slow leak that would only
affect the rafting use of the escape slide/raft. In light of this, the
FAA has determined that accomplishment of paragraph (a) of this AD to
require modification of the slide/raft within 36 months after the
effective date of this AD is adequate in ensuring operational safety.
No change to the final rule is necessary in this regard.
Request To Revise Paragraph (a) of the Proposed Rule
One commenter questions the effectiveness of the proposed repair
(modification) action of adding a chafing patch, as specified by
paragraph (a) of the proposed AD, since that patch may cause wear of
another component, or simply delay the onset of a hole from wear. The
commenter states that ``a corrective action to eliminate the
interference and subsequent repetitive abrasion would seem more
appropriate in order to solve this problem.''
The FAA does not concur with the commenter's request to revise the
action (modification) required by paragraph (a) of the proposed AD.
Although the FAA acknowledges the concerns of the commenter regarding
corrective action to eliminate damage to the slide/raft, the FAA has
evaluated this modification for
[[Page 66755]]
its wear resistance and determined that modification of the slide/raft,
in accordance with the requirements of paragraph (a) of the AD, is
adequate to ensure the continued safety of the affected fleet.
Request To Extend the Compliance Time in Paragraph (b)
One commenter requests that the compliance time in paragraph (b) of
the proposed AD be extended from ``As of the effective date of this
AD'' to ``As of 30 days after the effective date of this AD.'' The
commenter contends that the compliance time should be extended to allow
additional time for obtaining the slide/raft spares and to ensure that
sufficient stock levels of those parts can be maintained.
The FAA does not concur with the commenter's request to extend the
compliance time in paragraph (b) of the proposed AD to 30 days. The FAA
considers that the specified compliance time allows sufficient time for
obtaining spares and maintaining stock levels. Further, the intent of
that paragraph is to prohibit the installation of spares that have been
determined to create an unsafe condition, and to simply require the use
of one part rather than another. In general, once an unsafe condition
has been determined to exist, it is the FAA's policy not to allow that
condition to be introduced into the fleet. When it is determined that
approved parts are immediately available to operators, the installation
of unsafe parts after the effective date of the AD is prohibited.
Further, the FAA considers that the period of time between publication
of the final rule AD in the Federal Register and the effective date of
the final rule (usually 30 days) is sufficient to provide operators
with an opportunity to determine their immediate need for modified
spares and to obtain them. However, in individual cases where this is
not possible, every AD contains a provision that allows an operator to
obtain an extension of compliance time based upon a specific showing of
need. The FAA considers that this policy does increase safety and does
not impose undue burdens on operators. Therefore, no change to the
final rule is necessary in this regard.
Conclusion
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the changes previously
described. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Cost Impact
There are approximately 445 Model 757-200 and -300 series airplanes
of the affected design in the worldwide fleet. The FAA estimates that
310 airplanes of U.S. registry will be affected by this AD, that it
will take approximately 5 work hours per airplane to accomplish the
modification, and that the average labor rate is $60 per work hour.
Required parts will cost approximately $145 per airplane. Based on
these figures, the cost impact of the AD on U.S. operators is estimated
to be $137,950, or $445 per airplane.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the 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 adopted herein will 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 final rule does not have sufficient federalism
implications to warrant the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it may be obtained
from the Rules Docket at the location provided under the caption
ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends 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:
99-24-11 Boeing: Amendment 39-11435. Docket 99-NM-89-AD.
Applicability: Model 757-200 and -300 series airplanes, equipped
with Air Cruisers Company slide/raft evacuation systems having part
and serial numbers identified in Table 1 of this AD; certificated in
any category.
Table 1.--Air Cruisers Company Slide/Raft Evacuation Systems Subject to This AD
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Name Part No. Serial No.
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Air Cruisers............................ D30657-( )....................... Prior to 1132.
Air Cruisers............................ D30658-( )....................... Prior to 0859.
Air Cruisers............................ D30659-( )....................... Prior to 0860.
Air Cruisers............................ 61570-( )........................ Prior to 0321.
Air Cruisers............................ 61475-( )........................ Prior to 0137.
Air Cruisers............................ 61475-( )........................ 0138, 0139.
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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 (c) of
this AD. The request should include an assessment of
[[Page 66756]]
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 holes in the inflatable portion of the slide/raft
evacuation system, which could result in the slide/raft being less
effective as a raft during an emergency water landing, accomplish
the following:
Modification
(a) Within 36 months after the effective date of this AD, modify
the slide/raft evacuation system in accordance with Air Cruisers
Company Service Bulletin 757-105-25-51, dated January 29, 1999.
Spares
(b) As of the effective date of this AD, no person shall install
a slide/raft evacuation system having a part number and serial
number identified in Table 1 of this AD, on any airplane, unless
that slide/raft evacuation system has been modified in accordance
with Air Cruisers Company Service Bulletin 757-105-25-51, dated
January 29, 1999.
Alternative Methods of Compliance
(c) 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.
Special Flight Permits
(d) 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.
Incorporation by Reference
(e) The modification shall be done in accordance with Air
Cruisers Company Service Bulletin 757-105-25-51, dated January 29,
1999. This incorporation by reference was approved by the Director
of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51. Copies may be obtained from Air Cruisers Company, Technical
Publications Department, P.O. Box 180, Belmar, New Jersey 07719-
0180. Copies may be inspected at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the
Office of the Federal Register, 800 North Capitol Street, NW., suite
700, Washington, DC.
(f) This amendment becomes effective on January 4, 2000.
Issued in Renton, Washington, on November 18, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-30628 Filed 11-29-99; 8:45 am]
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