Federal Aviation Administration, DOT
Section 29.27

Section 29.33

Center of gravity limits.

The extreme forward and aft centers
of gravity and, where critical, the extreme lateral centers of gravity must
be established for each weight established under Section 29.25. Such an extreme
may not lie beyond - 
(a) The extremes selected by the applicant;
(b) The extremes within which the
structure is proven; or
(c) The extremes within which compliance with the applicable flight requirements is shown.
[Amdt. 29-3, 33 FR 965, Jan. 26, 1968]

Section 29.29 Empty
weight
and
responding center of gravity.

cor-

(a) The empty weight and corresponding center of gravity must be
determined by weighing the rotorcraft
without the crew and payload, but
with - 
(1) Fixed ballast;
(2) Unusable fuel; and
(3) Full operating fluids, including - 
(i) Oil;
(ii) Hydraulic fluid; and
(iii) Other fluids required for normal
operation of rotorcraft systems, except
water intended for injection in the engines.
(b) The condition of the rotorcraft at
the time of determining empty weight
must be one that is well defined and
can be easily repeated, particularly
with respect to the weights of fuel, oil,
coolant, and installed equipment.
(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. 29-15, 43 FR 2326, Jan. 16,
1978]

Section 29.31

Removable ballast.

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Removable ballast may be used in
showing compliance with the flight requirements of this subpart.
Section 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 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,

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