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helicopter, and should also keep
clear of the exit and approach paths,
just in case you have to drop a load.
The loaders then give an affirmative
signal to the marshaller, who gives
you the "move upwards" signal until
the slack has been taken up. You will
increase hover height slowly, until
the strain is taken, with the loaders
guiding the strops as necessary,
taking care to be free to move away
quickly should the need arise. At all
times in the event of engine failure,
the ground staff must move in the
opposite direction that the helicopter
would go, e.g. JetRanger to the left,
staff to the right, or the opposite for
a Squirrel (it depends which way the
blades rotate). They should not turn
their back on the load, or get directly
underneath it, or the flight path.
Neither should they wrap lines
directly around their wrists or
bodies. When finished, they should
clear the area as soon as possible.
As you take up the weight and the
rope stretches, the difference in
performance will immediately
become obvious—it will feel as if
you're attached to a large rubber
band. Once you're hovering, and the
marshaller is sure that the load is
clear of the ground (and you are sure
you can lift safely, flashing the
landing lamp once to indicate this),
28 The Helicopter Pilot’s Handbook
the marshaller should check behind
you for other aircraft and give the
affirmative signal, as you will find it
difficult to do a half-turn to check
for yourself. Keep a close eye on
your Ts and Ps at this point – if you
don’t have a power reserve, the load
is too heavy and you will have less
control at the destination. You will
find that once a Bell reaches its limit,
that's as far as it will get, but an AS
350, if you sit for a few seconds at
full power, will corkscrew up a little
more (don't confuse this with a Bell
taking a few extra seconds to gather
up its skirts, so to speak).
For extra lift in the 204B, reduce the
RPM to 98%. For a 500D, change
the lateral angle of the rotor disc.
Another tip for using less power
when lifting (for N American
rotation, anyway) is to place the nose
45° to the left with the wind on the
right, and move forward, to
straighten into wind with the right
pedal. This uses a little less torque
and allows you to take a little more
fuel or be easier on the machine.
A load should "spring" slightly into
the air, or at least come off cleanly
(experience will tell you the
difference). If it just about makes it,
or is a strain even to get it to move,
don't do it. Once off, the machine
will feel quite sluggish, as if it's tied
to the ground.
Move forward slowly, giving due
regard to the load's inertia, without
alternately slowing down and
speeding up, or you will confuse it.
Rather, move forward and keep
going to allow the load to follow,
which sometimes takes a bit of
courage, to see how it flies. Make all
control movements smoothly and
evenly, keeping the downwash inside
the rotor disk – if you have to, take
out your aggression on the collective
(see also Longlining, below). Try not
to allow the load to sink, as, if it hits
the ground or gets tied up in a tree it
will trip you (there is a natural
tendency to sink as you go forward
anyway). The torque used at this
point will give you a good idea of
what is needed for landing, so be
careful if you are going to a higher
altitude (it reduces at about 2-3% per
1000 feet in a 206).
One technique used in New
Zealand, when you are near all-up
weight and lifting the load into the
hover would be difficult, is to stretch
the longline out behind, attach it to
the helicopter and, keeping it taut,
build up some speed in a parabolalike
manoeuvre before lifting the
load (it's called the slingshot and I’m
told it requires some practice).
However, if a log lifted this way
starts spinning, it will undo the rope,
so another way is to get a 300-foot
line, get into the hover as far back as
possible with a taut line and take off
straight ahead to get some
translational lift. This tends to crack
the blades, though.
Once in flight, remember that the
load is the part that should be kept
straight and level, not the helicopter,
and keep away from anything
underneath that could be damaged
(well, try anyway!). Only with
imminent danger to the aircraft
　
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本文鏈接地址：The Helicopter Pilot’s Handbook(18)