[Federal Register Volume 64, Number 183 (Wednesday, September 22, 1999)]
[Rules and Regulations]
[Pages 51200-51202]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-24535]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-SW-46-AD; Amendment 39-11331; AD 99-17-17]
RIN 2120-AA64
Airworthiness Directives; Robinson Helicopter Company Model R44
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) 99-17-17 which was sent
previously to all known U.S. owners and operators of Robinson
Helicopter Company (RHC) Model R44 helicopters by individual letters.
This AD requires, prior to further
[[Page 51201]]
flight, replacing certain yoke assemblies with airworthy yoke
assemblies. This amendment is prompted by an incident in which, during
cruise flight, the pilot heard a loud bang and no tail rotor
effectiveness due to a cracked yoke assembly. RHC has identified the
manufacturing lots associated with the failed yoke assembly. The
actions specified by this AD are intended to prevent failure of the
yoke assembly, which could result in loss of main and tail rotor drive
and subsequent loss of control of the helicopter.
DATES: Effective October 7, 1999, to all persons except those persons
to whom it was made immediately effective by Emergency Priority Letter
AD 99-17-17, issued on August 13, 1999, 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 October 7, 1999.
Comments for inclusion in the Rules Docket must be received on or
before November 22, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Regional Counsel, Southwest Region,
Attention: Rules Docket No. 99-SW-46-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137.
The applicable service information may be obtained from Robinson
Helicopter Company, 2901 Airport Drive, Torrance, California 90505
telephone (310) 539-0508, fax (310) 539-5198. This information may be
examined at the FAA, Office of the Regional Counsel, Southwest Region,
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: Elizabeth Bumann, Aerospace Engineer,
FAA, Los Angeles Aircraft Certification Office, Propulsion Branch, 3960
Paramount Blvd., Lakewood, California 90712, telephone (562) 627-5265,
fax (562) 627-5210.
SUPPLEMENTARY INFORMATION: On August 13, 1999, the FAA issued Emergency
Priority Letter AD 99-17-17, applicable to RHC Model R44 helicopters,
which requires, prior to further flight, replacing certain yoke
assemblies with airworthy yoke assemblies. That action was prompted by
an incident in which, during cruise flight, the pilot heard a loud bang
and noticed no tail rotor effectivity after entering autorotation. An
investigation revealed that the yoke assembly, which connects the main
rotor gearbox pinion shaft to the forward flexplate, had failed at a
weld joint due to a crack. The cause of the crack is unknown but still
under investigation. RHC has identified the manufacturing lots
associated with the failed yoke. This condition, if not corrected,
could result in failure of the yoke assembly, loss of main and tail
rotor drive, and subsequent loss of control of the helicopter.
The FAA has reviewed RHC R44 Service Bulletin SB-35, dated July 26,
1999, which prescribes procedures for identifying the manufacturing lot
for each yoke assembly, part number (P/N) C908-1C, and for removing and
replacing the yoke assembly.
Since the unsafe condition described is likely to exist or develop
on other RHC Model R44 helicopters of the same type design, the FAA
issued Emergency Priority Letter AD 99-17-17 to prevent failure of the
yoke assembly, which could result in loss of main and tail rotor drive
and subsequent loss of control of the helicopter. The AD requires,
prior to further flight, replacing the yoke assembly, P/N C908-1C, from
Lot Nos. 36B, 37, and 38, with an airworthy yoke assembly from a lot
other than 36B, 37, or 38. The actions must be accomplished in
accordance with the service bulletin described previously. The short
compliance time involved is required because the previously described
critical unsafe condition can adversely affect the structural integrity
of the helicopter. Therefore, replacing any yoke assembly, P/N C908-1C,
from Lot Nos. 36B, 37, and 39, is required prior to further flight, and
this AD must be issued immediately.
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 13, 1999 to all known U.S. owners and operators of RHC
Model R44 helicopters. These conditions still exist, and the AD is
hereby published in the Federal Register as an amendment to section
39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it
effective to all persons.
The FAA estimates that 75 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 the average labor
rate is $60 per work hour. Required parts will cost approximately $840
per helicopter. Based on these figures, the total cost impact of the AD
on U.S. operators is estimated to be $72,000, assuming that the yoke
assembly is replaced in each helicopter.
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 No. 99-SW-46-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
[[Page 51202]]
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 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 adding a new airworthiness directive
to read as follows:
AD 99-17-17 Robinson Helicopter Company: Amendment 39-11331. Docket
No. 99-SW-46-AD.
Applicability: Model R44 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
otherwise 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 request approval for an
alternative method of compliance in accordance with paragraph (c) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required prior to further flight, unless
accomplished previously.
To prevent failure of the yoke assembly, which could result in
loss of main and tail rotor drive and subsequent loss of control of
the helicopter, accomplish the following:
(a) Determine, by inspection, if the yoke assembly, part number
(P/N) C908-1C, from Lot No. 36B, 37, or 38 is installed.
Note 2: Yoke assemblies, P/N C908-1C, from Lot Nos. 36B, 37, and
38 were installed as original equipment in R44 helicopters, Serial
Numbers (S/N) 0219 and 0535 through 0608 (except S/N's 0565, 0582,
and 0592).
(b) Replace any yoke assembly, P/N C908-1C, from Lot No. 36B,
37, or 38, with an airworthy yoke assembly from a lot other than
36B, 37, or 38 in accordance with the compliance procedure, steps 2
through 12, of Robinson Helicopter Company R44 Service Bulletin SB-
35, dated July 26, 1999.
(c) 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 3: 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.
(d) Special flight permits will not be issued.
(e) The replacement of the yoke assembly shall be done in
accordance with the compliance procedure, steps 2 through 12, of
Robinson Helicopter Company R44 Service Bulletin SB-35, dated July
26, 1999. 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 Robinson Helicopter
Company, 2901 Airport Drive, Torrance, California 90505 telephone
(310) 539-0508, fax (310) 539-5198. Copies may be inspected at the
FAA, Office of the Regional Counsel, Southwest Region, 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.
(f) This amendment becomes effective on [insert date 15 days
after date of publication in the Federal Register], to all persons
except those persons to whom it was made immediately effective by
Emergency Priority Letter AD 99-17-17, issued August 13, 1999, which
contained the requirements of this amendment.
Issued in Fort Worth, Texas, on September 13, 1999.
Eric Bries,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 99-24535 Filed 9-21-99; 8:45 am]
BILLING CODE 4910-13-U
