Airworthiness Directives; Hiller Aircraft Corporation Model UH- 12A, UH-12B, UH-12C, UH-12D, and UH-12E Helicopters

[Federal Register Volume 62, Number 195 (Wednesday, October 8, 1997)]
[Rules and Regulations]
[Pages 52489-52490]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-26621]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-SW-32-AD; Amendment 39-10151; AD 97-20-15]
RIN 2120-AA64


Airworthiness Directives; Hiller Aircraft Corporation Model UH-
12A, UH-12B, UH-12C, UH-12D, and UH-12E Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to Hiller Aircraft Corporation Model UH-12A, UH-12B, 
UH-12C, UH-12D, and UH-12E helicopters, that currently requires a dye 
penetrant inspection of the head of the main rotor outboard tension-
torsion (T-T) bar pin for cracks; a visual inspection of the outboard 
T-T bar pin for proper alignment and an adjustment, if necessary; and, 
installation of shims at the inboard end of the drag strut. This 
amendment requires the same actions required by the existing AD, but 
allows a magnetic particle inspection of the T-T bar pin as an 
alternative to the currently required dye penetrant inspection, and 
requires reporting the results of the inspections only if cracks are 
found, rather than reporting all results of inspections as required by 
the existing AD. This amendment is prompted by an FAA analysis of a 
comment to the existing AD, and the fact that no cracks have been 
reported since the issuance of the existing AD. The actions specified 
by this AD are intended to prevent cracks in the head area of the 
outboard T-T bar pin, which could result in loss of in-plane stability 
of the main rotor blade and subsequent loss of control of the 
helicopter.

DATES: Effective November 12, 1997.

    The incorporations by reference of certain publications listed in 
the regulations were approved by the Director of the Federal Register 
as of June 23, 1995 (60 FR 30184, June 8, 1995).

ADDRESSES: The service information referenced in this AD may be 
obtained from Hiller Aircraft Corporation, 3200 Imjin Road, Marina, 
California 93933-5101, telephone (408) 384-4500, fax (408) 883-3648. 
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. Charles Matheis, Aerospace 
Engineer, FAA, Los Angeles Aircraft Certification Office, 3960 
Paramount Blvd., Lakewood, California 90712-4137, telephone (562) 627-
5235, fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 95-12-02, 
Amendment 39-9252 (60 FR 30184), which is applicable to Hiller Model 
UH-12A, UH-12B, UH-12C, UH-12D, and UH-12E helicopters, was published 
in the Federal Register on January 7, 1997 (62 FR 951). That action 
proposed to require (1) an inspection of the alignment of the outboard 
T-T bar pin and an adjustment, if necessary; and (2) an inspection for 
cracks in the head of the outboard T-T bar pin using a dye penetrant 
method or a magnetic particle method. Additionally, that action 
proposed to require, within 25 hours TIS or at the next 100 hour 
inspection, whichever occurs first, the installation of shims between 
the inboard end of the drag strut and the outboard T-T bar pin.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comment received.
    The one commenter states that AD 95-12-02 should be eliminated, and 
that the requirement to report results of each 100 hour TIS inspection 
to the FAA should be discontinued, unless a crack is found. The 
commenter states that they have not experienced a T-T bar pin failure 
in 30 years of service history, and that if the procedures in the 
manufacturer's service information is followed, the AD is not needed. 
The FAA concurs that the reporting of the inspection should be 
accomplished only if the inspection reveals a crack. However, the FAA 
does not concur that the AD should be eliminated. The

[[Page 52490]]

National Transportation Safety Board recommended that the FAA issue an 
AD to make the requirements of the applicable service information 
mandatory. The FAA concurred, and issued AD 95-12-02. Based on an FAA 
analysis, the FAA has determined that the amendment will not be 
removed, but the reporting requirement will be changed.
    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 as proposed.
    The FAA estimates that 700 helicopters of U.S. registry will be 
affected by this AD, that it will take approximately 2 work hours per 
helicopter to accomplish the required actions, and that the average 
labor rate is $60 per work hour. Required parts will cost approximately 
$700 per pin. Based on these figures, the total cost impact of the AD 
on U.S. operators is estimated to be $574,000, assuming one pin must be 
replaced on every helicopter in the fleet.
    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 removing Amendment 39-9252 (60 FR 
30184), and by adding a new airworthiness directive (AD), Amendment 39-
10151, to read as follows:

97-20-15  Hiller Aircraft Corporation: Amendment 39-10151. Docket 
No. 96-SW-32-AD. Supersedes AD 95-12-02, Amendment 39-9252.

    Applicability: Model UH-12A, UH-12B, UH-12C, UH-12D, and UH-12E 
helicopters, 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 (e) 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 cracks in the head area of the outboard tension-
torsion (T-T) bar pin, which could result in loss of in-plane 
stability of the main rotor blade and subsequent loss of control of 
the helicopter, accomplish the following:
    (a) Within 25 hours time-in-service (TIS) after the effective 
date of this AD, or at the next 100 hour inspection, whichever 
occurs first, and thereafter at intervals not to exceed 100 hours 
TIS, inspect the alignment of the outboard T-T bar pin, part number 
(P/N) 51452, and adjust the alignment, if necessary, in accordance 
with Hiller Aviation Service Letter (SL) 51-2, dated March 31, 1978.
    (b) Within 25 hours TIS after the effective date of this AD, or 
at the next 100 hour inspection, whichever occurs first, and 
thereafter at intervals not to exceed 100 hours TIS, inspect the 
head of the outboard T-T bar pin for cracks using a dye penetrant or 
magnetic particle inspection method.
    (c) If a crack is found as a result of the inspection required 
by paragraph (b) of this AD, report the results within 7 working 
days following the inspection to the Manager, Los Angeles Aircraft 
Certification Office, Attention Charles Matheis, ANM-120L, 3960 
Paramount Blvd., Lakewood, California 90712-4137. Include the 
helicopter model number, serial number, and total TIS of the 
outboard T-T bar pin in the report. Reporting requirements have been 
approved by the Office of Management and Budget and assigned OMB 
control number 2120-0056.
    (d) Within 25 hours TIS after the effective date of this AD, or 
at the next 100 hour inspection, whichever occurs first, install 
shims between the inboard end of the drag strut and the outboard T-T 
bar pin in accordance with the Accomplishment Instructions of Hiller 
Aviation Service Bulletin No. 51-9, dated April 8, 1983.
    (e) 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, Los Angeles 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, Los Angeles 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 Los Angeles Aircraft Certification Office.

    (f) 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.
    (g) The adjustment of the alignment of the T-T bar pin shall be 
done in accordance with Hiller Aviation SL 51-2, dated March 31, 
1978, and the installation of the shims shall be done in accordance 
with Hiller Aviation Service Bulletin No. 51-9, dated April 8, 1983. 
These incorporations by reference were approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51 as of June 23, 1995 (60 FR 30184, June 8, 1995). Copies may 
be obtained from Hiller Aircraft Corporation, 3200 Imjin Road, 
Marina, California 93933-5101, telephone (408) 384-4500, fax (408) 
883-3648. Copies may be inspected 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.
    (h) This amendment becomes effective on November 12, 1997.

    Issued in Fort Worth, Texas, on September 26, 1997.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-26621 Filed 10-7-97; 8:45 am]
BILLING CODE 4910-13-U

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