[Federal Register Volume 65, Number 90 (Tuesday, May 9, 2000)]
[Proposed Rules]
[Pages 26781-26783]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-11523]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-SW-57-AD]


Airworthiness Directives; Schweizer Aircraft Corporation Model 
269A, 269A-1, 269B, 269C, 269C-1, 269D, and TH-55A Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD) applicable to Schweizer Aircraft 
Corporation (Schweizer) Model 269A, 269A-1, 269B, 269C, 269C-1, and 
269D helicopters. That AD currently requires inspecting the tail rotor 
swashplate shaft (shaft) nut for looseness and, if loose, inspecting 
the shaft for proper size; subsequently inspecting the shafts not 
previously inspected; and replacing any undersized shaft prior to 
further flight. This new action would reduce the applicability by 
specifying certain serial number tail rotor pitch control (pitch 
control) assemblies and shipping dates but would add the Schweizer 
Model TH-

[[Page 26782]]

55A helicopter to the applicability. This proposal is prompted by the 
discovery of an undersized replacement shaft during routine 
maintenance. The actions specified by this proposed AD are intended to 
prevent failure of the shaft, loss of the tail rotor, and subsequent 
loss of control of the helicopter.

DATES: Comments must be received on or before July 10, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 99-SW-57-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137. You may also send comments electronically to 
the Rules Docket at the following address: [email protected]. 
Comments may be inspected at the Office of the Regional Counsel between 
9 a.m. and 3 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: George J. Duckett, Aviation Safety 
Engineer, New York Aircraft Certification Office, FAA, 10 Fifth Street, 
3rd Floor, Valley Stream, New York 11581, telephone (516) 256-7525, fax 
(516) 568-2716.

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 should 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 No. 99-SW-57-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, Office of the Regional Counsel, Southwest Region, 
Attention: Rules Docket No. 99-SW-57-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

Discussion

    The FAA issued AD 99-17-10, Amendment 39-11258, on August 4, 1999 
(64 FR 44823, August 18, 1999), to require inspecting the shaft nut for 
looseness and, if loose, inspecting the shaft, part number (P/N) 
269A6049-3, for proper size; subsequently inspecting the shafts not 
previously inspected; and replacing any undersized shaft prior to 
further flight. That action was prompted by the discovery of an 
undersized replacement shaft during routine maintenance. The 
requirements of that AD are intended to prevent failure of the shaft 
and subsequent loss of control of the helicopter.
    Since the issuance of that AD, the FAA has determined that the TH-
55A model helicopter could have an undersized shaft installed and 
should have been included in the applicability of AD 99-17-10. 
Additionally, we have received reports of undersized shafts shipped 
from the factory as spares between September 1 and December 1, 1998. 
This action requires inspecting each shaft nut for looseness and each 
shaft for improper size, replacing each shaft, as necessary, and adding 
Schweizer Model TH-55A to the applicability requirements.
    The FAA has reviewed Schweizer Service Bulletins B-271.1 for 
Schweizer Models 269A, 269A-1, 269B, 269C, and TH-55A; C1B-009.1 for 
the Model 269C-1; and DB-007.1 for the Model 269D, all dated October 
14, 1999. These service bulletins describe procedures for inspecting 
the shaft nut, P/N 269A6258, for looseness by using a firm hand 
pressure and inspecting the shaft, P/N 269A6049-3, for proper size.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other Schweizer Model 269A, 269A-1, 269B, 269C, 
269C-1, 269D and TH-55A helicopters of these same type designs, the 
proposed AD would supersede AD 99-17-10 to require inspecting the shaft 
nut, P/N 269A6258, for looseness; inspecting the shaft, P/N 269A6049-3, 
for proper size; and replacing any undersized shaft with an airworthy 
shaft of the proper size for helicopters with equipment installed as 
follows:
     Shaft, P/N 269A6049-3, shipped from the factory between 
September 1 and December 1, 1998, and installed after the helicopter 
was manufactured, or
     Pitch control assembly, P/N 269A6050-5, with serial number 
with an ``S'' prefix and number 1047 through 1061.
    The FAA estimates that 28 helicopters would be affected by this AD. 
For each helicopter, it would take 0.25 work hour to accomplish the 10-
hour inspection and 3.6 work hours to accomplish the inspection and 
replacement, if necessary, at the 100-hour or annual inspection 
interval. The average labor rate is $60 per work hour. Required parts 
would cost approximately $1400 per helicopter. Based on these figures, 
the total cost impact of the AD on U.S. operators is estimated to be 
$45,668.
    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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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 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 proposed 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:


[[Page 26783]]


    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-11258 and by 
adding a new airworthiness directive to read as follows:

Schweizer Aircraft Corporation: Docket No. 99-SW-57-AD. Supersedes 
AD 99-17-10, Amendment 39-11258, Docket No. 99-SW-31-AD.

    Applicability: Model 269A, 269A-1, 269B, 269C, 269C-1, 269D and 
TH-55A helicopters, with a tail rotor swashplate shaft (shaft), part 
number (P/N) 269A6049-3, or a tail rotor pitch control assembly 
(pitch control), P/N 269A6050-5, with a serial number (S/N) with an 
``S'' prefix and number 1047 through 1061, installed, certificated 
in any category.

    Note 1: This AD applies to each helicopter identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise modified, altered, or repaired in the area subject to the 
requirements of this AD. For helicopters 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 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 failure of the shaft, loss of the tail rotor, and 
subsequent loss of control of the helicopter, accomplish the 
following:
    (a) Within 10 hours time-in-service (TIS);
    (1) Determine whether the factory-installed shaft, part number 
(P/N) 269A6049-3, has been replaced with a shaft shipped from the 
factory between September 1 and December 1, 1998, inclusive, or if a 
pitch control, P/N 269A6050-5, with a S/N with an ``S'' prefix and 
numbers 1047 through 1061 is installed.
    (2) If the factory ship date for a replacement shaft cannot be 
positively determined, if the shipping date was between September 1 
and December 1, 1998, inclusive, or if the pitch control S/N has an 
``S'' prefix and number 1047 through 1061,
    (i) Before further flight and thereafter at intervals not to 
exceed 10 hours TIS, accomplish ``Procedure, Part I,'' of Schweizer 
Service Bulletins B-271.1 for Models 269A, 269A-1, 269B, 269C and 
TH-55A helicopters; C1B-009.1 for the Model 269C-1, or DB-007.1 for 
the Model 269D, all dated October 14, 1999 (SB), as applicable.
    (ii) At the next scheduled 100-hour or annual inspection, 
whichever occurs first, accomplish Part II, paragraphs a. through 
d., of the applicable SB. Shafts not meeting the requirements of 
paragraph d. of the applicable SB must be replaced with an airworthy 
shaft prior to further flight.
    (b) Before installing a replacement shaft, determine the date 
the shaft was shipped from the factory. If the date was between 
September 1 and December 1, 1998, inclusive, or cannot be 
determined, accomplish the inspections required by Part II, 
paragraph d., of the applicable SB prior to installation. Replace 
any unairworthy shaft with an airworthy shaft.
    (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, New York Aircraft Certification 
Office. Operators shall submit their requests through an FAA 
Principal Maintenance Inspector, who may concur or comment and then 
send it to the Manager, New York Aircraft Certification Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York Aircraft Certification Office.

    (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 helicopter to a location where 
the requirements of this AD can be accomplished.

    Issued in Fort Worth, Texas, on April 28, 2000.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 00-11523 Filed 5-8-00; 8:45 am]
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