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the particular helicopter being flown. Normally, in helicopters
with low climb rates, 500 f.p.m. is appropriate,
in helicopters capable of high climb rates, use a rate of
1,000 f.p.m.
To enter a constant rate climb, increase power to the
approximate setting for the desired rate. As power is
applied, the airspeed indicator is primary for pitch until
the vertical speed approaches the desired rate. At this
time, the vertical speed indicator becomes primary for
pitch. Change pitch attitude by reference to the attitude
indicator to maintain the desired vertical speed. When
the VSI becomes primary for pitch, the airspeed indicator
becomes primary for power. Primary and supporting
instruments for a stabilized constant rate climb are illustrated
in figure 12-19. Adjust power to maintain desired
airspeed. Pitch attitude and power corrections should be
closely coordinated. To illustrate this, if the vertical
speed is correct but the airspeed is low, add power. As
power is increased, it may be necessary to lower the
pitch attitude slightly to avoid increasing the vertical
rate. Adjust the pitch attitude smoothly to avoid overcontrolling.
Small power corrections usually will be
sufficient to bring the airspeed back to the desired indication.
LEVELOFF
The leveloff from a constant airspeed climb must be
started before reaching the desired altitude. Although the
amount of lead varies with the helicopter being flown
and your piloting technique, the most important factor is
vertical speed. As a rule of thumb, use 10 percent of the
vertical velocity as your lead point. For example, if the
rate of climb is 500 f.p.m., initiate the leveloff approximately
50 feet before the desired altitude. When the
proper lead altitude is reached, the altimeter becomes
primary for pitch. Adjust the pitch attitude to the level
flight attitude for that airspeed. Cross-check the altimeter
and VSI to determine when level flight has been
attained at the desired altitude. To level off at cruise airspeed,
if this speed is higher than climb airspeed, leave
the power at the climb power setting until the airspeed
approaches cruise airspeed, then reduce it to the cruise
power setting.
The leveloff from a constant rate climb is accomplished
in the same manner as the leveloff from a constant airspeed
climb.
STRAIGHT DESCENTS (CONSTANT
AIRSPEED AND CONSTANT RATE)
Adescent may be performed at any normal airspeed the
helicopter is capable of, but the airspeed must be determined
prior to entry. The technique is determined by
whether you want to perform a constant airspeed or a
constant rate descent.
ENTRY
If your airspeed is higher than descending airspeed, and
you wish to make a constant airspeed descent at the
descending airspeed, reduce power to the descending
power setting and maintain a constant altitude using
cyclic pitch control. When you approach the descending
airspeed, the airspeed indicator becomes primary
for pitch, and the torque meter is primary for power. As
you hold the airspeed constant, the helicopter begins to
descend. For a constant rate descent, reduce the power
40
50 60 70
80
90
100
110
0 120
10
20
30
TORQUE
PERCENT

 Supporting

Power

 

Supporting Pitch

and Bank
Primary Bank
Primary Power
Supporting Bank Primary Pitch
Figure 12-19. Flight instrument indications in a stabilized constant rate climb.
12-15
to the approximate setting for the desired rate. If the
descent is started at the descending airspeed, the airspeed
indicator is primary for pitch until the VSI
approaches the desired rate. At this time, the vertical
speed indicator becomes primary for pitch, and the
airspeed indicator becomes primary for power.
Coordinate power and pitch attitude control as was
described earlier for constant rate climbs.
LEVELOFF
The leveloff from a constant airspeed descent may be
made at descending airspeed or at cruise airspeed, if
this is higher than descending airspeed. As in a climb
leveloff, the amount of lead depends on the rate of
descent and control technique. For a leveloff at
descending airspeed, the lead should be approximately
10 percent of the vertical speed. At the lead altitude,
simultaneously increase power to the setting necessary
to maintain descending airspeed in level flight. At this
point, the altimeter becomes primary for pitch, and the
airspeed indicator becomes primary for power.
To level off at a higher airspeed than descending airspeed,
　
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本文鏈接地址：ROTORCRAFT FLYING HANDBOOK2(26)