[Federal Register Volume 61, Number 23 (Friday, February 2, 1996)]
[Proposed Rules]
[Pages 3882-3884]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-2263]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-SW-32-AD]
Airworthiness Directives; Robinson Helicopter Company Model R44
Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to Robinson Helicopter Company
(Robinson) Model R44 helicopters. This proposal would require an
adjustment to the low-RPM warning unit threshold to increase the
revolutions-per-minute (RPM) at which the warning horn and caution
light activate, and revisions to the R44 Rotorcraft Flight Manual that
prohibit flight with the throttle governor (governor) selected off,
except in certain situations. This proposal is prompted by an FAA
Technical Panel Review of Robinson accident history data which revealed
that main rotor (M/R) blade stall at abnormally low M/R RPM resulted in
accidents. The actions specified by the proposed AD are intended to
minimize the possibility of pilot mismanagement of the M/R RPM, which
could result in unrecoverable M/R stall and subsequent loss of control
of the helicopter.
DATES: Comments must be received by March 4, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Assistant Chief Counsel, Attention:
Rules Docket No. 95-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.
FOR FURTHER INFORMATION CONTACT: Ms. Elizabeth Bumann, Aerospace
Engineer, FAA, Los Angeles Aircraft Certification Office, 3960
Paramount Blvd., Lakewood, California 90712-4137, telephone (310) 627-
5265; fax (310) 627-5210.
[[Page 3883]]
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. 95-SW-32-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. 95-SW-32-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas
76137.
Discussion
This document proposes the adoption of a new AD that is applicable
to Robinson Model R44 helicopters, serial numbers (S/N) 0001 through
0183 and 0189, which would require resetting the warning unit to
activate the warning horn and caution light at 96 to 97% RPM, and
revisions to the R44 Rotorcraft Flight Manual that prohibit flight with
the governor selected off, except in certain situations. A recent FAA
Technical Panel review of Robinson accident history data revealed that
some Model R22 accidents resulted from pilot mismanagement of the M/R
RPM.
The Technical Panel noted that, with the throttle governor selected
off, the Model R44 demonstrates potential for rotor RPM decay similar
to the Model R22. This lead the Technical Panel to recommend that the
Model R44 be flown with the governor on with exceptions for inflight
system malfunction or emergency procedures training with an instructor
pilot. Additionally, the Technical Panel recommended an increase in the
RPM at which the warning horn and caution light activate, thereby
allowing additional time for the initiation of corrective action
between the activation of the warning horn and caution light and the
onset of M/R blade stall.
Based on this recommendation, Robinson issued Robinson Helicopter
Company R44 Service Bulletin SB-7A, Revised June 8, 1995, which
describes procedures for increasing the RPM threshold at which the
warning horn and caution light activate to avoid inadvertent low M/R
RPM. This condition, if not corrected, could result in M/R stall and a
subsequent loss of control of the helicopter.
Since an unsafe condition has been identified that is likely to
exist or develop on other Robinson Model R44 helicopters of the same
type design, the proposed AD would require an adjustment to the warning
horn and caution light threshold from 95 1% RPM to between
96% and 97% RPM to increase the RPM at which the warning horn and
caution light activate, and revisions to the R44 Rotorcraft Flight
Manual that prohibit flight with the governor selected off, with
exceptions for inflight system malfunction or emergency procedures
training with an instructor pilot.
The FAA estimates that 20 helicopters of U.S. registry would be
affected by this proposed AD, that it would take approximately 0.2 work
hours per helicopter to accomplish the proposed actions, and that the
average labor rate is $60 per work hour. Based on these figures, the
total cost impact of the proposed AD on U.S. operators is estimated to
be $240.
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 adding a new airworthiness directive
to read as follows:
Robinson Helicopter Company: Docket No. 95-SW-32-AD.
Applicability: Model R44 helicopters, serial numbers (S/N) 0001
through 0183 and 0189, 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 (c) 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 within 30 days after the effective date of
this AD, unless accomplished previously.
To minimize the possibility of pilot mismanagement of the main
rotor (M/R) RPM, which could result in M/R stall and subsequent loss
of control of the helicopter, accomplish the following:
(a) Adjust the A569-6 low-RPM warning unit so that the warning
horn and caution
[[Page 3884]]
light activate when the M/R RPM is between 96% and 97% rotor RPM in
accordance with the procedures contained in the Model R44
maintenance manual.
(b) Insert pages 2-7 of the FAA-approved Robinson Helicopter
Company R44 Rotorcraft Flight Manual, revised July 25, 1995, into
each Model R44 helicopter's flight manual, and make pen-and-ink
changes to pages 2-7 to add the word ``inflight'' before ``system
malfunction'', change ``and'' to ``or'', and add the phrase ``with
an instructor pilot'' at the end so that the affected limitation
will state ``Flight prohibited with governor selected off, with
exceptions for inflight system malfunction or emergency procedures
training with an instructor pilot.''
(c) 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, 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.
(d) 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 January 29, 1996.
Daniel P. Salvano,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 96-2263 Filed 2-1-96; 8:45 am]
BILLING CODE 4910-13-U