[Federal Register Volume 59, Number 122 (Monday, June 27, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-15146]
[[Page Unknown]]
[Federal Register: June 27, 1994]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 93-SW-07-AD; Amendment 39-8935; AD 94-12-07]
Airworthiness Directives: Sikorsky Aircraft Model S-58T Series
Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to Sikorsky Aircraft Model S-58T series helicopters,
that currently requires a one-time inspection of the engine drive shaft
assembly (drive shaft assembly) for cracks and loose balance weights.
This amendment requires initial and repetitive visual and florescent
penetrant inspections of the drive shaft assembly for cracks and
improperly installed rivets. This amendment is prompted by three
reported incidents of loose or missing drive shaft assembly balance
weights and two reported incidents of fatigue cracks on the drive shaft
assembly near the balance weight rivet hole. The actions specified by
this AD are intended to prevent failure of the drive shaft assembly,
loss of power to the rotor system, and a subsequent forced landing of
the helicopter.
DATES: Effective August 1, 1994.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of August 1, 1994.
ADDRESSES: The service information referenced in this AD may be
obtained from Sikorsky Aircraft Division, United Technologies
Corporation, North Main Street, Stratford, Connecticut 06601. This
information may be examined at the Federal Aviation Administration
(FAA), Office of the Assistant Chief Counsel, 2601 Meacham Boulevard,
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. Terry Fahr, Aerospace Engineer,
Boston Aircraft Certification Office, FAA, Engine and Propeller
Directorate, Aircraft Certification Service, 12 New England Executive
Park, Burlington, Massachusetts 01803, telephone (617) 238-7155, fax
(617) 238-7199.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 90-10-02,
Amendment 39-6590 (55 FR 18305, May 2, 1990), which is applicable to
Sikorsky Aircraft Model S-58T series helicopters, was published in the
Federal Register on August 31, 1993 (58 FR 45859). That action proposed
to require initial and repetitive visual and florescent penetrant
inspections of the engine drive shaft assembly for cracks and loose
balance weights, and replacement as necessary.
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.
The FAA estimates that 58 helicopters of U.S. registry will be
affected by this AD, that it will take approximately 18 work hours per
helicopter to accomplish the required actions, and that the average
labor rate is $55 per work hour. Based on these figures, the total cost
impact of the AD on U.S. operators is estimated to be $57,420.
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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing Amendment 39-6590 (55 FR
18305, May 2, 1990), and by adding a new airworthiness directive (AD),
Amendment 39-8935, to read as follows:
AD 94-12-07 Sikorsky Aircraft: Amendment 39-8935. Docket Number 93-
SW-07-AD. Supersedes AD 90-10-02, Amendment 39-6590.
Applicability: Model S-58T series helicopters, equipped with
engine drive shaft assembly (drive shaft assembly), part number (P/
N) 58350-10030-045 and subassembly P/N 58350-10030-046, or drive
shaft assembly, P/N 58350-10030-047 and subassemblies 58350-10030-
048 and -049, certificated in any category. The subassembly part
numbers will appear adjacent to the 58350-10030-045 and 58350-10030-
047 drive shaft assembly part numbers.
Compliance: Required as indicated, unless accomplished
previously. To prevent failure of the drive shaft assembly, loss of
power to the rotor system, and a subsequent forced landing of the
helicopter, accomplish the following:
(a) Within the next 25 hours' time-in-service (TIS) after the
effective date of this AD, or at the next removal of the drive shaft
assembly, P/N 58350-10030-045 and subassembly -046, or P/N 58350-
10030-047 and subassemblies -048 and -049, whichever comes first--
(1) Remove and inspect the drive shaft assembly for proper
installation of rivets, loose balance weights, and cracks in
accordance with paragraphs 2.A.(1), (2), and (4) of the
Accomplishment Instructions of Sikorsky Alert Service Bulletin (ASB)
No. 58B35-31A, Revision A, dated February 17, 1993.
(2) If a crack, loose balance weight, or improper rivet
installation is found, replace the drive shaft assembly with an
airworthy drive shaft assembly.
(b) Within the next 25 hours' TIS after compliance with
paragraph (a) of this AD, and at every 25 hours' TIS thereafter,
visually inspect the drive shaft assembly for cracks in accordance
with paragraph 2.B. of the Accomplishment Instructions of ASB No.
58B35-31A, Revision A, dated February 17, 1993.
(c) For drive shaft assembly, P/N 58350-10030-045 and
subassembly -046, that have not been reworked in accordance with
Sikorsky Overhaul Repair Instruction (ORI) No. 58350-001, Revision
A, dated November 18, 1992, within 250 hours' TIS after the
inspections required by paragraph (a) of this AD, and thereafter at
intervals not to exceed 250 hours' TIS, remove and inspect the drive
shaft assembly in accordance with paragraph 2.C. of the
Accomplishment Instructions of ASB No. 58B35-31A, Revision A, dated
February 17, 1993.
(d) For drive shaft assembly, P/N 58350-10030-047 and
subassemblies -048 and -049, and additionally, for drive shaft
assembly, P/N 58350-10030-045 and subassembly -046, that have been
reworked in accordance with ORI No. 58350-001, Revision A, dated
November 18, 1992, within 2,500 hours' TIS after the inspections
required by paragraph (a) of this AD, and thereafter at intervals
not to exceed 2,500 hours' TIS, remove and inspect the drive shaft
assembly in accordance with subparagraph 2.D of the Accomplishment
Instructions of ASB No. 58B35-31A, Revision A, dated February 17,
1993.
(e) 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, Boston 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, Boston Aircraft Certification Office.
Note: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Boston 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 inspections and replacement, if necessary, shall be done
in accordance with Sikorsky Alert Service Bulletin No. 58B35-31A,
Revision A, dated February 17, 1993. 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
Sikorsky Aircraft Division, United Technologies Corporation, North
Main Street, Stratford, Connecticut 06601. Copies may be inspected
at the FAA, Office of the Assistant Chief Counsel, 2601 Meacham
Boulevard, 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 August 1, 1994.
Issued in Fort Worth, Texas, on June 2, 1994.
Larry M. Kelly,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 94-15146 Filed 6-24-94; 8:45 am]
BILLING CODE 4910-13-P
