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

[Federal Register Volume 60, Number 198 (Friday, October 13, 1995)]
[Rules and Regulations]
[Pages 53265-53266]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-25330]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-SW-02-AD; Amendment 39-9387; AD 95-21-02]


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to Schweizer Aircraft Corporation and Hughes 
Helicopters, Inc. Model 269A, 269A-1, 269B, 269C, and TH-55A 
helicopters with certain main rotor (M/R) drive shafts installed, that 
currently requires a one-time radiographic inspection or other non-
destructive inspection of certain M/R drive shafts for cracks, 
distortion, corrosion, or other surface damage, at specified time 
intervals or upon the occurrence of specified conditions. This 
amendment requires the same inspections as the previous AD, but expands 
the applicability of certain inspections to additional models of the 
affected helicopters, and excludes certain M/R drive shafts from 
certain inspections. This amendment is prompted by a reevaluation as a 
result of a comment to the previous AD suggesting the need to expand 
the applicability of certain inspections to additional models of the 
affected helicopters and to exclude certain M/R drive shafts from 
certain inspections. The actions specified by this AD are intended to 
prevent structural failure of the M/R drive shaft, separation of the M/
R from the helicopter, and subsequent loss of control of the 
helicopter.

DATES: Effective November 17, 1995.
    The incorporation by reference of certain publications listed in 
the regulations was previously approved by the Director of the Federal 
Register as of October 29, 1993 (58 FR 53120, October 14, 1993).

ADDRESSES: The service information referenced in this AD may be 
obtained from Schweizer Aircraft Corporation, P.O. Box 147, Elmira, New 
York 14902. This information may be examined at the FAA, Office of the 
Assistant Chief Counsel, 2601 Meacham Blvd., Room 663, Fort Worth, 
Texas; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mr. Raymond J. O'Neill, Aerospace 
Engineer, FAA, New York Aircraft Certification Office, New England 
Region, 10 5th Street, Valley Stream, New York 11581, telephone (516) 
256-7505, fax (516) 568-2716.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 93-14-06, 
Amendment 39-8630 (58 FR 53120, October 14, 1993), which is applicable 
to Schweizer Aircraft Corporation and Hughes Helicopters, Inc. Model 
269A, 269A-1, 269B, 269C, and TH-55A helicopters, was published in the 
Federal Register on November 30, 1994 (59 FR 61298). That action 
proposed to require a one-time radiographic inspection or other non-
destructive inspection of the applicable M/R drive shafts of all 
affected Model 269 series helicopters. That action also proposed to 
change paragraph (b) of AD 93-14-06 to exclude those replacement drive 
shafts having an ``SZ'' or ``ZS'' prefix from mandatory inspections 
prior to their installation.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposal or the FAA's determination of the cost to the public. The FAA 
has determined that air safety and the public interest require the 
adoption of the rule as proposed, except for editorial changes and 
adding explanatory Note 1, relating to the scope of the applicability 
statement when modifications, alterations, or repairs have been made in 
the area subject to the requirements of the AD. The FAA has determined 
that these changes will neither increase the economic burden on any 
operator nor increase the scope of the AD.
    The FAA estimates that 1,364 helicopters of U.S. registry will be 
affected by this AD, that it will take approximately 10 work hours per 
helicopter to accomplish the required actions, and that the average 
labor rate is $60 per work hour. Based on these figures, the total cost 
impact of the AD on U.S. operators is estimated to be $818,400.
    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 USC 106(g), 40101, 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-8630 (58 FR 
53120, October 14, 1993), and by adding a new airworthiness directive 
(AD), Amendment 39-9387, to read as follows:

AD 95-21-02  Schweizer Aircraft Corporation and Hughes Helicopters, 
Inc: Amendment 39-9387. Docket No. 94-SW-02-AD. Supersedes AD 93-14-
06, Amendment 39-8630.

    Applicability: Model 269A, 269A-1, 269B, 269C, and TH-55A 
helicopters, with main rotor (M/R) drive shaft part number (P/N) 
269A5305-3 or 269A5305-11 installed, except those M/R drive shafts 
having a serial 

[[Page 53266]]
number with a prefix of ``SZ'' or ``ZS'', certificated in any category.

    Note 1: This AD applies to each helicopter 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 helicopters that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must use the authority 
provided in paragraph (d) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition, or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any helicopter from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent structural failure of the M/R drive shaft, separation 
of the M/R from the helicopter, and subsequent loss of control of 
the helicopter, accomplish the following:
    (a) Inspect the M/R drive shaft for cracks, distortion, 
corrosion, or other surface damage, using either the radiographic 
inspection procedure or the other non-destructive inspection 
procedure in accordance with Part I of Schweizer Service Bulletin B-
255.1 (SB), dated February 1, 1993. Conduct this inspection at the 
time intervals and under the conditions stated in the following:
    (1) Inspect M/R drive shafts with serial numbers (S/N) S0001 
through S1111, and any drive shaft without an ``S'' prefix on the S/
N, having less than 1,100 hours time-in-service (TIS) on the 
effective date of this AD--
    (i) At the next removal of the drive shaft;
    (ii) Within the next 600 hours TIS;
    (iii) Prior to attaining 1,200 hours total TIS; or
    (iv) Within 1 year after the effective date of this AD, 
whichever occurs first.
    (2) Inspect M/R drive shafts with S/N S0001 through S1111, and 
any drive shaft without an ``S'' prefix on the S/N with 1,100 hours 
or more TIS on the effective date of this AD--
    (i) Within the next 100 hours TIS; or
    (ii) At the next removal of the drive shaft; or
    (iii) Within 1 year after the effective date of this AD, 
whichever occurs first.
    (3) Inspect M/R drive shafts with S/N S1112 and higher, 
regardless of the number of the total hours TIS on the effective 
date of this AD--
    (i) Within the next 25 hours TIS;
    (ii) At the next removal of the drive shaft; or
    (iii) Within 1 year after the effective date of this AD, 
whichever occurs first.
    (4) Inspect the M/R drive shaft before further flight if M/R 
vibrations occur that cannot be corrected with track and balance 
procedures, or if M/R track and balance procedures are required more 
than once within a 25-hour TIS interval.
    (b) Inspect any replacement M/R drive shaft, except those that 
have a serial number with a prefix of ``SZ'' or ``ZS'', prior to 
installation in accordance with the procedures in Part I of the SB, 
dated February 1, 1993.
    (c) Replace any unairworthy M/R drive shaft with an airworthy M/
R drive shaft before further flight.
    (d) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used when approved by the Manager, New York Aircraft Certification 
Office, FAA. 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.

    (e) 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) only for those helicopters that do not 
exhibit M/R vibrations due to uncorrected out-of-track or out-of-
balance conditions specified in paragraph (a)(4) of this AD. The 
special flight permit allows flight of the helicopter to a location 
where the requirements of this AD can be accomplished.
    (f) The inspections and replacement, if necessary, shall be done 
in accordance with Schweizer Service Bulletin B-255.1 (SB), dated 
February 1, 1993. This incorporation by reference was previously 
approved by the Director of the Federal Register in accordance with 
5 U.S.C. 552(a) and 1 CFR part 51 as of October 29, 1993 (58FR53120, 
October 14, 1993). Copies may be obtained from Schweizer Aircraft 
Corporation, P.O. Box 147, Elmira, New York 14902. Copies may be 
inspected at the FAA, Office of the Assistant Chief Counsel, 2601 
Meacham Blvd., Room 663, Fort Worth, Texas 76137; or at the Office 
of the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.
    (g) This amendment becomes effective on November 17, 1995.

    Issued in Fort Worth, Texas, on September 28, 1995.
Daniel P. Salvano,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 95-25330 Filed 10-12-95; 8:45 am]
BILLING CODE 4910-13-U

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