Section 29.341

14 CFR Ch. I (1-1-19 Edition)

Section=

V cos a
R

where - 
V = The airspeed along the flight path
(f.p.s.);
a = The angle between the projection, in the
plane of symmetry, of the axis of no
feathering and a line perpendicular to
the flight path (radians, positive when
axis is pointing aft);
W = The angular velocity of rotor (radians
per second); and
R = The rotor radius (ft.).

Section 29.351 Yawing conditions.
(a) Each rotorcraft must be designed
for the loads resulting from the maneuvers specified in paragraphs (b) and (c)
of this section, with - 
(1) Unbalanced aerodynamic moments about the center of gravity
which the aircraft reacts to in a rational or conservative manner considering
the principal masses furnishing the reacting inertia forces; and
(2) Maximum main rotor speed.
(b) To produce the load required in
paragraph (a) of this section, in unaccelerated flight with zero yaw, at forward speeds from zero up to 0.6 VNE - 
(1) Displace the cockpit directional
control suddenly to the maximum deflection limited by the control stops or
by the maximum pilot force specified
in Section 29.397(a);
(2) Attain a resulting sideslip angle
or 90Section, whichever is less; and
(3) Return the directional control
suddenly to neutral.
(c) To produce the load required in
paragraph (a) of the section, in unaccelerated flight with zero yaw, at forward speeds from 0.6 VNE up to VNE or
VH, whichever is less - 
(1) Displace the cockpit directional
control suddenly to the maximum deflection limited by the control stops or
by the maximum pilot force specified
in Section 29.397(a);
(2) Attain a resulting sideslip angle
or 15Section, whichever is less, at the lesser
speed of VNE or VH;

[Amdt. 29-26, 55 FR 8002, Mar. 6, 1990, as
amended by Amdt. 29-41, 62 FR 46173, Aug. 29,
1997]

Section 29.361

Engine torque.

The limit engine torque may not be
less than the following:
(a) For turbine engines, the highest
of - 
(1) The mean torque for maximum
continuous power multiplied by 1.25;
(2) The torque required by Section 29.923;
(3) The torque required by Section 29.927; or
(4) The torque imposed by sudden engine stoppage due to malfunction or
structural failure (such as compressor
jamming).
(b) For reciprocating engines, the
mean torque for maximum continuous
power multiplied by - 
(1) 1.33, for engines with five or more
cylinders; and
(2) Two, three, and four, for engines
with four, three, and two cylinders, respectively.
[Amdt. 29-26, 53 FR 34215, Sept. 2, 1988]

CONTROL SURFACE AND SYSTEM LOADS
Section 29.391

General.

Each auxiliary rotor, each fixed or
movable stabilizing or control surface,
and each system operating any flight
control must meet the requirements of
SectionSection 29.395 through 29.399, 29.411, and
29.427.
[Amdt. 29-26, 55 FR 8002, Mar. 6, 1990, as
amended by Amdt. 29-41, 62 FR 46173, Aug. 29,
1997]

Section 29.395

Control system.

(a) The reaction to the loads prescribed in Section 29.397 must be provided by - 
(1) The control stops only;
(2) The control locks only;
(3) The irreversible mechanism only
(with the mechanism locked and with
the control surface in the critical positions for the effective parts of the system within its limit of motion);
(4) The attachment of the control
system to the rotor blade pitch control

588

VerDate Sep<11>2014

12:50 Apr 30, 2019

Jkt 247046

PO 00000

Frm 00598

Fmt 8010

Sfmt 8010

Y:\SGML\247046.XXX

247046

EC28SE91.087</MATH>

spaschal on DSK3GDR082PROD with CFR

Section 29.341 Gust loads.
Each rotorcraft must be designed to
withstand, at each critical airspeed including hovering, the loads resulting
from vertical and horizontal gusts of 30
feet per second.

(3) Vary the sideslip angles of paragraphs (b)(2) and (c)(2) of this section
directly with speed; and
(4) Return the directional control
suddenly to neutral.