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path and decelerating (position 2). Use the proper
antitorque pedal for trim. Since this angle is steeper
than a normal approach angle, you need to reduce the
collective more than that required for a normal
approach. Continue to decelerate with slight aft
cyclic, and smoothly lower the collective to maintain
the approach angle. As in a normal approach,
reference the touchdown point on the windshield to
determine changes in approach angle. This point is in
a lower position than a normal approach. Aft cyclic is
required to decelerate sooner than a normal approach,
and the rate of closure becomes apparent at a higher
altitude. Maintain the approach angle and rate of
descent with the collective, rate of closure with the
cyclic, and trim with antitorque pedals. Use a crab
above 50 feet and a slip below 50 feet for any crosswind
that might be present.
Loss of effective translational lift occurs higher in a
steep approach (position 3), requiring an increase in the
collective to prevent settling, and more forward cyclic
to achieve the proper rate of closure. Terminate the
approach at hovering altitude above the intended landing
point with zero groundspeed (position 4). If power
has been properly applied during the final portion of
the approach, very little additional power is required in
the hover.
15° Descent
Figure 10-4. Steep approach to a hover.
Balloon—Gaining an excessive amount of altitude as a result of an
abrupt flare.
10-5
COMMON ERRORS
1. Failing to maintain proper r.p.m. during the entire
approach.
2. Improper use of collective in maintaining the
selected angle of descent.
3. Failing to make antitorque pedal corrections to
compensate for collective pitch changes during
the approach.
4. Slowing airspeed excessively in order to remain
on the proper angle of descent.
5. Inability to determine when effective translational
lift is lost.
6. Failing to arrive at hovering altitude and attitude,
and zero groundspeed almost simultaneously.
7. Low r.p.m. in transition to the hover at the end of
the approach.
8. Using too much aft cyclic close to the surface,
which may result in the tail rotor striking the surface.
SHALLOW APPROACH AND
RUNNING/ROLL-ON LANDING
Use a shallow approach and running landing when a
high-density altitude or a high gross weight condition,
or some combination thereof, is such that a normal or
steep approach cannot be made because of insufficient
power to hover. [Figure 10-5] To compensate for this
lack of power, a shallow approach and running landing
makes use of translational lift until surface contact is
made. If flying a wheeled helicopter, you can also use a
roll-on landing to minimize the effect of downwash.
The glide angle for a shallow approach is approximately
5°. Since the helicopter will be sliding or rolling
to a stop during this maneuver, the landing area must
be smooth and long enough to accomplish this task.
TECHNIQUE
A shallow approach is initiated in the same manner as
the normal approach except that a shallower angle of
descent is maintained. The power reduction to initiate
the desired angle of descent is less than that for a normal
approach since the angle of descent is less (position 1).
As you lower the collective, maintain heading with
proper antitorque pedal pressure, and r.p.m. with the
throttle. Maintain approach airspeed until the apparent
rate of closure appears to be increasing. Then, begin to
slow the helicopter with aft cyclic (position 2).
As in normal and steep approaches, the primary control
for the angle and rate of descent is the collective, while
the cyclic primarily controls the groundspeed.
However, there must be a coordination of all the controls
for the maneuver to be accomplished successfully.
The helicopter should arrive at the point of touchdown
at or slightly above effective translational lift. Since
translational lift diminishes rapidly at slow airspeeds,
the deceleration must be smoothly coordinated, at the
same time keeping enough lift to prevent the helicopter
from settling abruptly.
Just prior to touchdown, place the helicopter in a level
attitude with the cyclic, and maintain heading with the
antitorque pedals. Use the cyclic to keep the heading
and ground track identical (position 3). Allow the
helicopter to descend gently to the surface in a straightand-
level attitude, cushioning the landing with the
collective. After surface contact, move the cyclic
slightly forward to ensure clearance between the
tailboom and the rotor disc. You should also use the
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ROTORCRAFT FLYING HANDBOOK1(72)
