[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