spaschal on DSK3GDR082PROD with CFR

Section 29.923

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

torque, neutral torque as required by
the power applied to the main rotor,
and maximum left turning torque.
(3) Each maximum control position
must be held for at least 10 seconds,
and the rate of change of control position must be at least as rapid as that
for normal operation.
(d) Endurance tests; 90 percent of maximum continuous run. One hour of continuous operation at 90 percent of maximum continuous torque and the maximum speed for use with 90 percent of
maximum continuous torque must be
conducted.
(e) Endurance tests; 80 percent of maximum continuous run. One hour of continuous operation at 80 percent of maximum continuous torque and the minimum speed for use with 80 percent of
maximum continuous torque must be
conducted.
(f) Endurance tests; 60 percent of maximum continuous run. Two hours or, for
helicopters for which the use of either
30-minute OEI power or continuous OEI
power is requested, 1 hour of continuous operation at 60 percent of maximum continuous torque and the minimum speed for use with 60 percent of
maximum continuous torque must be
conducted.
(g) Endurance tests; engine malfunctioning run. It must be determined
whether malfunctioning of components, such as the engine fuel or ignition systems, or whether unequal engine power can cause dynamic conditions detrimental to the drive system.
If so, a suitable number of hours of operation must be accomplished under
those conditions, 1 hour of which must
be included in each cycle, and the remaining hours of which must be accomplished at the end of the 20 cycles.
If no detrimental condition results, an
additional hour of operation in compliance with paragraph (b) of this section
must be conducted in accordance with
the run schedule of paragraph (b)(1) of
this section without consideration of
paragraph (b)(2) of this section.
(h) Endurance tests; overspeed run. One
hour of continuous operation must be
conducted at maximum continuous
torque and the maximum power-on
overspeed expected in service, assuming that speed and torque limiting devices, if any, function properly.

(i) Endurance tests; rotor control positions. When the rotor controls are not
being cycled during the tie-down tests,
the rotor must be operated, using the
procedures prescribed in paragraph (c)
of this section, to produce each of the
maximum thrust positions for the following percentages of test time (except
that the control positions need not
produce loads or blade flapping motion
exceeding the maximum loads or motions encountered in flight):
(1) For full vertical thrust, 20 percent.
(2) For the forward thrust component, 50 percent.
(3) For the right thrust component,
10 percent.
(4) For the left thrust component, 10
percent.
(5) For the aft thrust component, 10
percent.
(j) Endurance tests, clutch and brake
engagements. A total of at least 400
clutch and brake engagements, including the engagements of paragraph (b)
of this section, must be made during
the takeoff torque runs and, if necessary, at each change of torque and
speed throughout the test. In each
clutch engagement, the shaft on the
driven side of the clutch must be accelerated from rest. The clutch engagements must be accomplished at the
speed and by the method prescribed by
the applicant. During deceleration
after each clutch engagement, the engines must be stopped rapidly enough
to allow the engines to be automatically disengaged from the rotors and
rotor drives. If a rotor brake is installed for stopping the rotor, the
clutch, during brake engagements,
must be disengaged above 40 percent of
maximum continuous rotor speed and
the rotors allowed to decelerate to 40
percent of maximum continuous rotor
speed, at which time the rotor brake
must be applied. If the clutch design
does not allow stopping the rotors with
the engine running, or if no clutch is
provided, the engine must be stopped
before each application of the rotor
brake, and then immediately be started
after the rotors stop.
(k) Endurance tests; OEI power run - 
(1) 30-minute OEI power run. For rotorcraft for which the use of 30-minute
OEI power is requested, a run at 30-

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