[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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