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the helicopter in a dangerous position, requiring a high
degree of skill in making a safe autorotative landing.
TECHNIQUE
Before attempting a maximum performance takeoff,
bring the helicopter to a hover, and determine the
excess power available by noting the difference
between the power available and that required to hover.
You should also perform a balance and flight control
check and note the position of the cyclic. Then position
the helicopter into the wind and return the helicopter to
the surface. Normally, this maneuver is initiated from
the surface. After checking the area for obstacles and
other aircraft, select reference points along the takeoff
path to maintain ground track. You should also consider
alternate routes in case you are not able to complete the
maneuver. [Figure 10-1]
Begin the takeoff by getting the helicopter light on the
skids (position 1). Pause and neutralize all aircraft movement.
Slowly increase the collective and position the
cyclic so as to break ground in a 40 knot attitude. This is
approximately the same attitude as when the helicopter is
light on the skids. Continue to slowly increase the collective
until the maximum power available is reached. This
large collective movement requires a substantial increase
in pedal pressure to maintain heading (position 2). Use the
cyclic, as necessary, to control movement toward the
desired flight path and, therefore, climb angle during the
maneuver (position 3). Maintain rotor r.p.m. at its maximum,
and do not allow it to decrease since you would
probably have to lower the collective to regain it. Maintain
these inputs until the helicopter clears the obstacle, or until
reaching 50 feet for demonstration purposes (position 4).
Then, establish a normal climb attitude and reduce power
(position 5). As in any maximum performance maneuver,
the techniques you use affect the actual results. Smooth,
coordinated inputs coupled with precise control allow the
helicopter to attain its maximum performance.
COMMON ERRORS
1. Failure to consider performance data, including
height/velocity diagram.
2. Nose too low initially, causing horizontal flight
rather than more vertical flight.
3. Failure to maintain maximum permissible r.p.m.
4. Abrupt control movements.
5. Failure to resume normal climb power and airspeed
after clearing the obstacle.
RUNNING/ROLLING TAKEOFF
A running takeoff in a skid-type helicopter or a rolling
takeoff in a wheeled helicopter is sometimes used when
conditions of load and/or density altitude prevent a sustained
hover at normal hovering altitude. However, you
should not attempt this maneuver if you do not have
sufficient power to hover, at least momentarily. If the
helicopter cannot be hovered, its performance is unpredictable.
If the helicopter cannot be raised off the
surface at all, sufficient power might not be available
to safely accomplish the maneuver. If you cannot
momentarily hover the helicopter, you must wait for
conditions to improve or off-load some of the weight.
To accomplish a safe running or rolling takeoff, the surface
area must be of sufficient length and smoothness,
and there cannot be any barriers in the flight path to
interfere with a shallow climb.
For wheeled helicopters, a rolling takeoff is sometimes
used to minimize the downwash created during a take-
Figure 10-1. Maximum performance takeoff. off from a hover.
10-3
TECHNIQUE
Refer to figure 10-2. To begin the maneuver, first align
the helicopter to the takeoff path. Next, increase the
throttle to obtain takeoff r.p.m., and increase the collective
smoothly until the helicopter becomes light on the
skids or landing gear (position 1). Then, move the
cyclic slightly forward of the neutral hovering position,
and apply additional collective to start the forward
movement (position 2). To simulate a reduced power
condition during practice, use one to two inches less
manifold pressure, or three to five percent less torque,
than that required to hover.
Maintain a straight ground track with lateral cyclic and
heading with antitorque pedals until a climb is established.
As effective translational lift is gained, the helicopter
becomes airborne in a fairly level attitude with little or no
pitching (position 3). Maintain an altitude to take advantage
of ground effect, and allow the airspeed to increase
toward normal climb speed. Then, follow a climb profile
that takes you through the clear area of the height/velocity
diagram (position 4). During practice maneuvers, after
you have climbed to an altitude of 50 feet, establish the
　
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