曝光台 注意防骗
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customer unloading any old
junk on the insurance if you
have to drop anything.
· Precision longlining means what it
says, and usually involves
moving drills, etc. because they
are heavy and cannot be moved
once they are on the ground.
The real finesse with longlining
comes when moving loads that take
up nearly all the payload available,
although you should never use it all,
because you leave yourself with no
margins, ether with power or pedals.
Some companies (and customers)
will expect you to "inadvertently"
use more power than the maximum
to get the load moving in the first
place – that is, it's well known that
you are not allowed to intentionally
use more torque than that in the
Limitations section of the Flight
Manual, but you can do so by
accident. What you do is up to you,
but that margin is for getting you out
of trouble, like when a load sucks
you into a hole and you need to give
it a gentle landing – you should
always aim to do the complete job
within 100%, which is what
performance graphs are for, talking
of which, remember that humidity
can reduce their figures by as much
as 10% or more, so be careful after a
good shower. Put more simply,
overtorquing (within limits) is for
landing, not taking off, but you knew
that already. Another consideration
is looking after your engine – many
turbine failures are the result of
pulling too many cycles from
minimum to maximum Ng, so if you
don't need 100% torque, it's best not
to use it. It's also best not to reduce
the collective lever to the bottom
when descending, either, and to
make power changes gently,
avoiding over- and undershoots.
It's when an experienced longliner
gets on the controls that the whole
process becomes like poetry in
motion, with the load and helicopter
becoming a symbiotic pair, when
every ounce of performance is
extracted from the machine, even to
extent of bouncing a load against a
tree to set it in motion (without
damaging it of course!).
Naturally, with the top half of your
body twisted round, you have to
learn some new motor skills. Some
people say there is a tendency to pull
the cyclic the same way as you are
Specialised Tasks 35
leaning, and back, but I found a
bigger factor was the drift that
occurs when you lower the
collective, which you learn to cope
with automatically when learning to
hover. To take a LongRanger as an
example, from being nicely
positioned over the load with a
vertical line, and reducing power,
unless you make a conscious
correction, you will find yourself
very much to the left of the load
very quickly. It's too easy to accept
the resulting parallax position as the
normal one and try to take off again
with a slanted line, which means a
potential for dragging the load.
This is something you therefore
need to practice, that is, keeping the
hook directly over the load and the
line in sight whilst pushing the
controls in a strange direction. If
you're likely to get the same training
as me (i.e. none at all), get into a
high hover, without a line first of all,
and practice spot turns, keeping the
belly hook over the target (it is behind
you!). Get your head out of the
window and get used to landing and
taking off by looking at the back of
your skid, so you avoid the transition
from vertical to horizontal reference.
Maybe do a circuit or two, as well.
This also helps you if the engine
stops, with no time to start looking
horizontally – just moving your
focus from the load to the
instruments, or vice versa, takes about
two seconds, let alone reorganising
your whole body.
Next, graduate to a line with a lightly
loaded cargo net, followed by a
heavier one, finally working up to an
unloaded hook. You will find that,
up to a point, the heavier the load is,
the easier longlining is to do.
There is also a natural tendency to
tighten up on the controls, the same
as when you start mountain flying
the first time. The same advice
applies, however, which is to
RELAX! If you have to take your
aggression out on anything, do it on
the collective, as the key to good
longlining is proper downwash
management, and spilling it with
jerky cyclic movements does not
help at all (this is one reason why
there are holes in bearpaws, to let
the downwash through. Even a ski
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The Helicopter Pilot’s Handbook(23)
