[Federal Register Volume 62, Number 4 (Tuesday, January 7, 1997)]
[Proposed Rules]
[Pages 951-953]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-251]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-SW-32-AD]
Airworthiness Directives; Hiller Aircraft Corporation Model UH-
12A, UH-12B, UH-12C, UH-12D, and UH-12E 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 Hiller Aircraft Corporation
(Hiller) 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 action would require the same actions required
by the existing AD, but would allow a magnetic particle inspection of
the T-T bar pin as an alternative to the currently required dye
penetrant inspection, and would require 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 proposal 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 the proposed 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: Comments must be received by March 10, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Assistant Chief Counsel, Attention:
Rules Docket No. 96-SW-32-AD, 2601 Meacham Blvd., Room 663, Fort Worth,
Texas 76137. Comments may be inspected at this location between 9:00
a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.
The service information referenced in the proposed rule may be
obtained from Hiller Aircraft Corporation, 3200 Imjin Road, Marina,
California 93933-5101. This information may be examined at the FAA,
Office of the Assistant Chief Counsel, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas.
FOR FURTHER INFORMATION CONTACT: Mr. Charles Matheis, Aerospace
Engineer, FAA, Los Angeles Aircraft Certification Office, 3960
Paramount Blvd., Lakewood, California 90712-4137, telephone (310) 627-
5235, fax (310) 627-5210.
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. 96-SW32-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 Assistant Chief Counsel, Attention: Rules
Docket No. 96-SW-32-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas
76137.
Discussion
On May 25, 1995, the FAA issued AD 95-12-02, Amendment 39-9252 (60
FR 30184) to require for Hiller Model UH-12A, UH-12B, UH-12C, UH-12D,
and UH-12E helicopters, within 25 hours time-in-service (TIS) or at the
next 100 hour inspection, whichever occurs first, and thereafter at
intervals not to exceed 100 hours TIS: (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
[[Page 952]]
penetrant method. Additionally, that AD requires, 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. That action was prompted by two accidents
involving failure of the outboard T-T bar pin on Hiller UH-12E
helicopters. The requirements of that 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.
Since the issuance of that AD, the FAA has received a comment
suggesting that paragraph (b) of the existing AD should specifically
identify the compliance time for the inspection, even though the
compliance time is stated in paragraph (a). The FAA agrees with the
commenter, and the wording of paragraph (b) has been changed to clarify
the inspection compliance time. Additionally, the same commenter
requested that an alternate method of compliance for the inspection be
included in paragraph (b) of the existing AD. The FAA agrees, and
paragraph (b) has been changed to allow the use of a magnetic particle
inspection as well as a dye penetrant inspection required by the
existing AD. One additional commenter states that misalignment of the
drag strut fork and the main rotor blade may be causing cracks. While
the cause of the cracks is uncertain, the FAA has determined that the
recurring inspections required by this AD should detect misalignments
and cracks that could lead to failure of the T-T bar pin.
Since an unsafe condition has been identified that is likely to
exist or develop on other Hiller Model UH-12A, UH12B, UH-12C, UH-12D,
and UH-12E helicopters of the same type design, the proposed AD would
supersede AD 95-12-02 to require, within 25 hours TIS or at the next
100 hour inspection, whichever occurs first, and thereafter at
intervals not to exceed 100 hours TIS: (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, the proposed AD requires, 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.
The FAA estimates that 700 helicopters of U.S. registry would be
affected by this proposed AD, that it would take approximately 2 work
hours per helicopter to accomplish the proposed actions, and that the
average labor rate is $60 per work hour. Required parts would cost
approximately $700 per pin. Based on these figures, the total cost
impact of the proposed 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 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, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
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 the 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 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:
Authority: 49 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing Amendment 39-9252 (60 FR
30184, June 8, 1995), and by adding a new airworthiness directive (AD),
to read as follows:
Hiller Aircraft Corporation: 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 hours TIS 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
[[Page 953]]
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. Issued in Fort
Worth, Texas, on December 30, 1996.
Larry M. Kelly,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 97-251 Filed 1-6-97; 8:45 am]
BILLING CODE 4910-13-U
