曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
room, try to move forward slightly,
as this will bring the tail up, away
from the garbage.
So as not to use pedals too much,
you can use the cyclic to turn the
machine if need be. It is always a
good idea to do a clearing turn
before taking off, but often you
cannot, so exercise extra caution if
you think someone may be behind
you. In a Bell, as you go out of a
clearing, a little aft cyclic will
produce a little extra lift, but don't
expect the same from an AS 350, or
you will clip the trees.
Anyway, always be prepared to break
off at any time, even if only seconds
from success. Never commit
yourself till the very last moment.
Short cuts don't exist with
mountains—they've been around a
lot longer than you have!
Landing sites on the bottoms of
valleys often have difficult access,
and frequently leave no escape route
once an approach has started. In this
case, it's important to have safe
power reserves before committing
yourself. In any case, placing the
aircraft downwind near to ground
should be avoided, but if you have
to, go low and slow when
approaching downwind with a last
minute turn into wind.
In snow, try landing with the sun
behind you, as the aircraft shadow
will give you a useful guide to the
ground slope and surface and
provide a focus for a sight picture
approach. Some people use the
landing light. For takeoff, try not to
hover too much. A jump takeoff is
useful if little power is available,
where you get light on the skids,
proceed to the edge with full RPM
and tip yourself over the edge. Good
fun, but you should be able to hover
at least for a moment, just in case
your C of G is out. In a confined
area, for a JetRanger, at least, you
need about 15% torque in hand to
do a proper vertical takeoff, so
you’re probably OK if you’re
hovering at about 80%.
Near the end of a cliff (or the deck
of a ship), try and keep the tips of
the rotors as far as possible over the
edge, to avoid a vortex formed by
wind movement over the edge (a
backlash) mixing with your
downwash, which will affect the
airflow so much that you will need
more power in a low hover. It’s a
similar effect to the recirculation
found when hovering near a
building, where the accelerated air
going through the disc actually pulls
your machine towards the wall, and
more power is used to stop it.
Log Pads and Platforms
Log pads are used when slopes are
steep, on rough ground. The quick
and easy one is a single log across
the slope for your rear skid to a solid
mat of smaller ones. They can be
slippery! Platforms are still made
from logs, but are much more
refined. The problem with them all
is, you can mostly only land one way,
and there may be no room to turn
once you get there, so approaching
with the wind in totally the wrong
direction is often the only choice. In
such cases, you need much more
anticipation than normal, and the
willingness to throw things away
Specialised Tasks 75
much earlier. Of course, you don’t
actually have to land, but it’s often
worth a try. As with landing on rigs
or ships, it may be possible to
approach to the hover next to it and
move sideways on. Here is a typical
log arrangement (note the larger one
at the back):
Here is a typical forestry landing site
(look at the slash on the ground):
Summary
· Mountains take no sh*t from
nobody.
· Make turns away from rising
ground.
· Use the eye-level pass as much
as possible.
· Use controls for different
functions, collective for speed,
etc.
· Take off as cleanly as possible
to avoid getting snagged
Night Flying
Night flying can be pleasant—there's
less traffic, you tend not to go in bad
weather and the air is denser, so the
engine and flying controls are more
responsive. However, the tendency
is not to allow single-engined night
flying on Commercial Air Transport,
but occasionally positioning may
take place with the pilot only on
board. This doesn't make it any
safer, but at least reduces the
number of questions in the House.
Don't forget there is no VFR at
night. Well, not in UK, anyway.
Searching for an overdue aircraft in
low light conditions causes lots of
problems, and route planning should
take account of this. Otherwise, it’s
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
The Helicopter Pilot’s Handbook(50)
