[Federal Register Volume 60, Number 246 (Friday, December 22, 1995)]
[Rules and Regulations]
[Pages 66488-66490]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-31139]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-SW-30-AD; Amendment 39-9463; AD 95-26-05]


Airworthiness Directives; Robinson Helicopter Company Model R44 
Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to Robinson Helicopter Company (RHC) Model R44 
helicopters, that currently requires revisions to the Limitations 
section, the Normal Procedures section, and the Emergency Procedures 
section of the R44 Rotorcraft Flight Manual, revised September 6, 1994. 
These revisions limit operations in high winds and turbulence; provide 
information about main rotor (M/R) stall and mast bumping; and provide 
recommendations for avoiding these situations. Additionally, emergency 
procedures are provided for use should certain conditions be 
encountered. This action would require similar revisions to the 
Limitations, Normal Procedures and Emergency Procedures sections 
required by the existing AD, but the revision to the Limitations 
section would prohibit only pilots without a certain level of 
experience and training from operating in the flight conditions 
specified. This action is prompted by data that indicates pilots who 
possess a certain level of experience and training are more able to 
recognize and react to the adverse meteorological conditions specified 
in the AD. The actions 

[[Page 66489]]
specified by this AD are intended to prevent M/R stall or mast bumping, 
which could result in the M/R blades contacting the fuselage causing 
failure of the M/R system and subsequent loss of control of the 
helicopter.

EFFECTIVE DATE: January 26, 1996.

FOR FURTHER INFORMATION CONTACT: Mr. Scott Horn, Aerospace Engineer, 
FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, Southwest 
Region, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 
222-5125, fax (817) 222-5961.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 95-04-13, 
Amendment 39-9165, which superseded Priority Letter AD 95-02-04, issued 
January 12, 1995, which is applicable to RHC Model R44 helicopters, was 
published in the Federal Register on October 12, 1995 (60 FR 53150). 
That action proposed to require revisions to the Limitations section, 
the Normal Procedures section, and the Emergency Procedures section of 
the R44 Rotorcraft Flight Manual, revised September 6, 1994. These 
revisions limit operations in high winds and turbulence; provide 
information about M/R stalls and mast bumping; and provide 
recommendations for avoiding these situations. Additionally, emergency 
procedures are provided for use should certain conditions be 
encountered. This supersedure will reduce limitations for pilots who 
have the flight experience specified by the AD and who have completed 
the SFAR No. 73 training.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comment received. The sole commenter agrees with the FAA's proposal 
that the FAA's exemption of those pilots with sufficient training and 
experience from limitations that might in some cases substantially 
restrict their Model R44 flight operations is justified.
    After careful review of the available data, including the comment, 
the FAA has determined that air safety and the public interest require 
the adoption of the rule as proposed.
    The FAA estimates that three helicopters of U.S. registry would be 
affected by this proposed AD, that it would take approximately one-half 
work hour 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 $90.
    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, 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), 40101, 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-9165, and by 
adding a new airworthiness directive (AD), Amendment 39-9463, to read 
as follows:

AD 95-26-05 Robinson Helicopter Company: Amendment 39-9463. Docket 
No. 95-SW-30-AD. Supersedes AD 95-04-13, Amendment 39-9165.

    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 
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 (b) 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 before further flight, unless accomplished 
previously.

    Note 2: Regardless of the experience level of the pilot 
manipulating the controls or the amount or quality of the awareness 
training received by the pilot manipulating the controls, these 
changes to the flight manual are in no way intended to authorize 
flight in any condition(s) or under any circumstance(s) that are 
otherwise contrary to other Federal Aviation Regulations.

    To prevent main rotor (M/R) stall or mast bumping, which could 
result in the M/R blades contacting the fuselage causing failure of 
the M/R system, and subsequent loss of control of the helicopter, 
accomplish the following:
    (a) Insert the following information into the Model R44 
Rotorcraft Flight Manual. Compliance with the Limitations section is 
mandatory. The Normal Procedures and Emergency Procedures sections 
are informational.

Limitations Section

    The following limitations (1-3) are to be observed unless the 
pilot manipulating the controls has logged 200 or more flight hours 
in helicopters, at least 50 of which must be in the RHC Model R44 
helicopter, and has completed the awareness training specified in 
Special Federal Aviation Regulation (SFAR) No. 73, issued February 
27, 1995.
    (1) Flight when surface winds exceed 25 knots, including gusts, 
is prohibited.
    (2) Flight when surface wind gust spreads exceed 15 knots is 
prohibited.
    (3) Continued flight in moderate, severe, or extreme turbulence 
is prohibited.
    Adjust forward airspeed to between 60 knots indicated airspeed 
(KIAS) and 0.7 V<INF>ne, but no lower than 60 KIAS, upon 
inadvertently encountering moderate, severe, or extreme turbulence.

    Note: Moderate turbulence is turbulence that causes: (1) changes 
in altitude or attitude; (2) variations in indicated airspeed; and 
(3) aircraft occupants to feel definite strains against seat belts.

Normal Procedures Section

Note

    Until the FAA completes its research into the conditions and 
aircraft characteristics that lead to main rotor blade/fuselage 
contact accidents, and corrective type design changes and operating 
limitations are identified, Model R44 pilots are strongly urged to 
become familiar with the following information and comply with these 
recommended procedures.
    Main Rotor Stall: Many factors may contribute to main rotor 
stall and pilots 

[[Page 66490]]
should be familiar with them. Any flight condition that creates 
excessive angle of attack on the main rotor blades can produce a 
stall. Low main rotor RPM, aggressive maneuvering, high collective 
angle (often the result of high-density altitude, over-pitching 
[exceeding power available] during climb, or high forward airspeed) 
and slow response to the low main rotor RPM warning horn and light 
may result in main rotor stall. The effect of these conditions can 
be amplified in turbulence. Main rotor stall can ultimately result 
in contact between the main rotor and airframe. Additional 
information on main rotor stall is provided in the Robinson 
Helicopter Company Safety Notices SN-10, SN-15, SN-20, SN-24, SN-27, 
and SN-29.
    Mast Bumping: Mast bumping may occur with a teetering rotor 
system when excessive main rotor flapping results from low ``G'' 
(load factor below 1.0) or abrupt control input. A low ``G'' flight 
condition can result from an abrupt cyclic pushover in forward 
flight. High forward airspeed, turbulence, and excessive sideslip 
can accentuate the adverse effects of these control movements. The 
excessive flapping results in the main rotor hub assembly striking 
the main rotor mast with subsequent main rotor system separation 
from the helicopter.
    To avoid these conditions, pilots are strongly urged to follow 
these recommendations:
    (1) Maintain cruise airspeeds greater than 60 KIAS and less than 
0.9 V<INF>ne.
    (2) Use maximum ``power-on'' RPM at all times during powered 
flight.
    (3) Avoid sideslip during flight. Maintain in-trim flight at all 
times.
    (4) Avoid large, rapid forward cyclic inputs in forward flight, 
and abrupt control inputs in turbulence.

Emergency Procedures Section

    (1) RIGHT ROLL IN LOW ``G'' CONDITION Gradually apply aft cyclic 
to restore positive ``G'' forces and main rotor thrust. Do not apply 
lateral cyclic until positive ``G'' forces have been established.
    (2) UNCOMMANDED PITCH, ROLL, OR YAW RESULTING FROM FLIGHT IN 
TURBULENCE.
    Gradually apply controls to maintain rotor RPM, positive ``G'' 
forces, and to eliminate sideslip. Minimize cyclic control inputs in 
turbulence; do not overcontrol.
    (3) INADVERTENT ENCOUNTER WITH MODERATE, SEVERE, OR EXTREME 
TURBULENCE.
    If the area of turbulence is isolated, depart the area; 
otherwise, land the helicopter as soon as practical.
    (b) 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, Rotorcraft Standards Staff, 
Rotorcraft Directorate, FAA. Operators shall submit their requests 
through an FAA Principal Maintenance Inspector, who may concur or 
comment and then send it to the Manager, Rotorcraft Standards Staff.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Rotorcraft Standards Staff.

    (c) Special flight permits, pursuant to sections 21.197 and 
21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 
21.199), will not be issued.
    (d) This amendment becomes effective on January 26, 1996.

    Issued in Fort Worth, Texas, on December 11, 1995.
Daniel P. Salvano,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 95-31139 Filed 12-21-95; 8:45 am]
BILLING CODE 4910-13-U