[Code of Federal Regulations]

[Title 14, Volume 1]

[Revised as of January 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 14CFR29.33]



[Page 651-652]

 

                     TITLE 14--AERONAUTICS AND SPACE

 

CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION

 

PART 29_AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT--Table 

of Contents

 

                            Subpart B_Flight

 

Sec. 29.33  Main rotor speed and pitch limits.



    (a) Main rotor speed limits. A range of main rotor speeds must be 

established that--

    (1) With power on, provides adequate margin to accommodate the 

variations in rotor speed occurring in any appropriate maneuver, and is 

consistent with the kind of governor or synchronizer used; and

    (2) With power off, allows each appropriate autorotative maneuver to 

be performed throughout the ranges of airspeed and weight for which 

certification is requested.

    (b) Normal main rotor high pitch limit (power on). For rotorcraft, 

except helicopters required to have a main rotor low speed warning under 

paragraph (e) of this section, it must be shown, with power on and 

without exceeding approved engine maximum limitations, that main rotor 

speeds substantially less than the minimum approved main rotor speed 

will not occur under any sustained flight condition. This must be met 

by--

    (1) Appropriate setting of the main rotor high pitch stop;

    (2) Inherent rotorcraft characteristics that make unsafe low main 

rotor speeds unlikely; or

    (3) Adequate means to warn the pilot of unsafe main rotor speeds.

    (c) Normal main rotor low pitch limit (power off). It must be shown, 

with power off, that--

    (1) The normal main rotor low pitch limit provides sufficient rotor 

speed, in any autorotative condition, under the most critical 

combinations of weight and airspeed; and

    (2) It is possible to prevent overspeeding of the rotor without 

exceptional piloting skill.

    (d) Emergency high pitch. If the main rotor high pitch stop is set 

to meet paragraph (b)(1) of this section, and if that stop cannot be 

exceeded inadvertently, additional pitch may be made available for 

emergency use.

    (e) Main rotor low speed warning for helicopters. For each single 

engine



[[Page 652]]



helicopter, and each multiengine helicopter that does not have an 

approved device that automatically increases power on the operating 

engines when one engine fails, there must be a main rotor low speed 

warning which meets the following requirements:

    (1) The warning must be furnished to the pilot in all flight 

conditions, including power-on and power-off flight, when the speed of a 

main rotor approaches a value that can jeopardize safe flight.

    (2) The warning may be furnished either through the inherent 

aerodynamic qualities of the helicopter or by a device.

    (3) The warning must be clear and distinct under all conditions, and 

must be clearly distinguishable from all other warnings. A visual device 

that requires the attention of the crew within the cockpit is not 

acceptable by itself.

    (4) If a warning device is used, the device must automatically 

deactivate and reset when the low-speed condition is corrected. If the 

device has an audible warning, it must also be equipped with a means for 

the pilot to manually silence the audible warning before the low-speed 

condition is corrected.



(Secs. 313(a), 601, 603, 604, and 605 of the Federal Aviation Act of 

1958 (49 U.S.C. 1354(a), 1421, 1423, 1424, and 1425); and sec. 6(c) of 

the Dept. of Transportation Act (49 U.S.C. 1655(c)))



[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as amended by Amdt. 29-3, 33 

FR 965, Jan. 26, 1968; Amdt. 29-15, 43 FR 2326, Jan. 16, 1978]



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