[Federal Register Volume 59, Number 9 (Thursday, January 13, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-141]
[[Page Unknown]]
[Federal Register: January 13, 1994]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 93-SW-21-AD; Amendment 39-8766; AD 93-15-10]
Airworthiness Directives; Enstrom Helicopter Corporation Model F-
28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and 280FX Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This document publishes in the Federal Register an amendment
adopting Airworthiness Directive (AD) 93-15-10 that was sent previously
to all known U.S. owners and operators of The Enstrom Helicopter
Corporation Model F-28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and
280FX helicopters by individual letters. This AD requires an initial
inspection of the composite-wrapped main rotor shaft for composite-
wrapping separation, red color residue, corrosion, or cracks, and
replacement of certain main rotor shafts. This amendment is prompted by
the discovery of a significant crack in a composite-wrapped main rotor
shaft. The actions specified by this AD are intended to prevent failure
of the main rotor shaft, loss of the main rotor, and subsequent loss of
control of the helicopter.
DATES: Effective January 28, 1994, to all persons except those persons
to whom it was made immediately effective by Priority Letter AD 93-15-
10, issued on August 3, 1993, which contained the requirements of this
amendment.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of January 28, 1994.
Comments for inclusion in the Rules Docket must be received on or
before March 14, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Assistant Chief Counsel, Attention:
Rules Docket No. 93-SW-21-AD, 2601 Meacham Boulevard, room 663, Fort
Worth, Texas 76137.
The applicable service information may be obtained from The Enstrom
Helicopter Corporation, Twin County Airport, P.O. Box 490, Menominee,
Michigan 49858. This information may be examined 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.
FOR FURTHER INFORMATION CONTACT: Mr. Joe McGarvey, Aerospace Engineer,
Chicago Aircraft Certification Office, FAA, Airframe Branch, Small
Airplane Directorate, 2300 East Devon Avenue, room 232, Des Plaines,
Illinois 60018, telephone (708) 294-7136, fax (708) 294-7834.
SUPPLEMENTARY INFORMATION: On August 3, 1993, the FAA issued Priority
Letter AD 93-15-10, applicable to The Enstrom Helicopter Corporation
Model F-28A, F-28C, F-28C2, F-28F, 280, 280C, 280F, and 280FX
helicopters, which requires an initial inspection of the composite-
wrapped main rotor shaft (shaft) for composite-wrapping separations,
red color residue, corrosion, or cracks, and replacement of certain
shafts. That action was prompted by the discovery of a significant
crack in a shaft. This condition, if not corrected, could result in
failure of the shaft, loss of the main rotor, and subsequent loss of
control of the helicopter.
The FAA has reviewed and approved The Enstrom Helicopter
Corporation Service Directive Bulletin No. 0083, dated July 16, 1993,
that describes an initial inspection of the shafts for evidence of
separation between the composite-wrapping and the shaft, corrosion, or
cracks. Service Directive Bulletin No. 0083 also specifies replacement
of certain shafts.
Since the unsafe condition described is likely to exist or develop
on other helicopters of the same type design, the FAA issued Priority
Letter AD 93-15-10 to prevent failure of the shaft, loss of the main
rotor, and subsequent loss of control of the helicopter. The AD
requires an initial inspection of the shaft, part number (P/N) 28-
13183, for composite-wrapping separation, red color residue, corrosion,
or cracks, and replacement of the shaft upon discovery of these
conditions. The AD also requires replacement of the shaft whenever
vibrations occur that cannot be corrected with track and balance
procedures or if track and balance procedures are required more than
once. Further, the AD requires replacement of any shaft, P/N 28-13183,
with an airworthy shaft, P/N 28-13140-11 or P/N 28-13104-1, within the
next 10 hours' time-in-service or at the next annual inspection after
the effective date of this AD, whichever occurs first. The actions are
required to be accomplished in accordance with the service directive
bulletin described previously.
Since it was found that immediate corrective action was required,
notice and opportunity for prior public comment thereon were
impracticable and contrary to the public interest, and good cause
existed to make the AD effective immediately by individual letters
issued on August 3, 1993, to all known U.S. owners and operators of The
Enstrom Helicopter Corporation Model F-28A, F-28C, F-28C2, F-28F, 280,
280C, 280F, and 280FX helicopters. These conditions still exist, and
the AD is hereby published in the Federal Register as an amendment to
Section 39.13 of part 39 of the Federal Aviation Regulations (FAR) to
make it effective to all persons.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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 that
summarizes each FAA-public contact concerned with the substance of this
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 93-SW-21-AD.'' The postcard will be date stamped and
returned to the commenter.
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.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the Rules Docket.
A copy of it, if filed, 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 14 CFR part
39 of the Federal Aviation Regulations 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 adding the following new
airworthiness directive:
The Enstrom Helicopter Corporation: Amendment 39-8766. Docket Number
93-SW-21-AD. Final Rule of a Priority Letter AD.
Applicability: Model F-28A, F-28C, F-28C2, F-28F, 280, 280C,
280F, and 280FX helicopters equipped with composite-wrapped main
rotor shaft, part number (P/N) 28-13183, certificated in any
category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent failure of the main rotor shaft (shaft), loss of the
main rotor, and subsequent loss of control of the helicopter,
accomplish the following:
(a) Before further flight, after the effective date of this
airworthiness directive (AD), perform a one-time inspection of the
shaft in accordance with paragraph 5.1 of The Enstrom Helicopter
Corporation Service Directive Bulletin No. 0083, dated July 16,
1993.
(b) If the shaft is found with composite-wrapping separation,
corrosion, red color residue or cracks during the inspections in
paragraph (a) of this AD, remove the shaft from further service and
install an airworthy shaft, P/N 28-13140-11 or P/N 28-13104-1.
(c) If main rotor (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, replace the shaft
with an airworthy shaft, P/N 28-13140-11 or P/N 28-13104-1, before
further flight.
(d) Within the next 10 hours' time-in-service, or at the next
annual inspection after the effective date of this AD, whichever
occurs first, remove the shaft, P/N 28-13183, and install an
airworthy shaft, P/N 28-13140-11 or P/N 28-13104-1.
(e) Installation of airworthy shafts, P/N 28-13140-11 or P/N 28-
13104-1, constitutes terminating action for the requirements of this
AD.
(f) An alternative method of compliance or adjustment of the
compliance time, which provides an acceptable level of safety, may
be used when approved by the Manager, Chicago Aircraft Certification
Office, 2300 East Devon Avenue, room 232, Des Plaines, IL 60018.
Operators shall submit their requests through an FAA Principal
Maintenance Inspector, who may concur or comment and then send it to
the Manager, Chicago Aircraft Certification Office.
Note: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Chicago Aircraft Certification Office.
(g) Special flight permits may be issued in accordance with FAR
21.197 and 21.199 to operate the helicopter to a location where the
requirements of only paragraphs (a) and (d) of this AD can be
accomplished.
(h) The inspection, removal and replacement shall be done in
accordance with The Enstrom Helicopter Corporation Service Directive
Bulletin No. 0083, dated July 16, 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 The Enstrom Helicopter Corporation, Twin County
Airport, P.O. Box 490, Menominee, Michigan 49858. 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.
(i) This amendment becomes effective January 28, 1994, to all
persons except those persons to whom it was made immediately
effective by Priority Letter AD 93-15-10, issued August 3, 1993,
which contained the requirements of this amendment.
Issued in Fort Worth, Texas, on December 3, 1993.
James D. Erickson,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 94-141 Filed 1-12-94; 8:45 am]
BILLING CODE 4910-13-P