Landing from a Hover
This maneuver is used to transition the helicopter from a hover to a
landing on the ground.
From a normal hover, decrease power to approach the ground. Inexperienced
pilots should avoid the normal tendance to look directly in front of the
helicopter. Better results will be obtained if you either look up at the
horizon, or halfway between the ground in front of the helicopter and
the horizon (normally this would be a spot 50-100 feet in front of the
helicopter). It is critical to be aware of the horizon, and looking too
close to the helicopter removes this from your vision.
You don't normally need to look down to judge your height above the ground.
Your peripheral vision will do this for you. When the ground seems to be
about level with your ears, you're about to touch down. When landing on an
elevated platform, your peripheral vision may not give you this feedback,
and you may have to glance down to judge altitude. The trick is not to stare
down, but to just take quick looks to monitor your progress toward the ground.
As you descend, ground effect will decrease your descent rate, and you will
have to continue to lower collective to maintain a steady descent rate. As
you are approaching the ground, allow ground effect to decrease your descent
rate for a softer touchdown. Don't allow your descent rate to stop, however.
You don't want to wallow around at a low skid height. Make sure you continue
to descend toward the ground.
Eventually a skid is going to touch the ground. If the helicopter is not
hovering perfectly level, this will cause the helicopter to pitch, roll,
or both as the fuselage transitions from hover attitude to the attitude
it assumes sitting on the skids. As it pitches and rolls, input opposite
cyclic just as you would on a slope landing, in order to prevent drift.
Many pilots will quickly get the collective down in order to get
weight on the skids, as this will stop any sliding motion. This is a bad
technique for a couple reasons. One, if the ground isn't level enough,
the helicopter could roll over (I've landed in tall grass that makes it
impossible to see the ground - one time there was a hole under the rear
of one of the skids. The helicopter started to tip over backward, but the
fact that we were slowly decreasing collective gave us plenty of time to
abort the landing and find a different spot to land on). Another bad
thing about lowering collective too quickly is that you are rapidly
lowering the blades toward the fuselage, and you increase the chance of
rotor to airframe contact on a gusty day.
The better technique is almost the reverse of the technique I described in
Takeoff to a Hover. Hover slowly down until
a skid touches. Balance there for a few seconds without allowing the
helicopter to drift around on the ground. Lower some more collective
and put a little more skid on the ground, while compensating for drift.
Keep doing this a stage at a time until you have slowly lowered the
helicopter all the way onto the ground. Practicing this will allow you
to land accurately every time.
Going for it!
A very common mistake is for pilots to descend until they estimate they
are almost on the ground, and then rapidly lower collective. It's the
reaction to the feeling "I just want to be on the ground". There are
multiple problems, the most typical being that sometimes you are higher
than you think you are, and you can get a fairly hard landing if you just
lower a lot of collective. Advice: descend until you think you are close
to the ground. Continue to descend at a slow rate until you feel a skid
touch. Continue to slowly lower collective, while making cyclic pitch
adjustments for any pitch and roll necessary to get onto the skids.
Overcontrolling near the ground
Lots of pilots start to over control when they are near the ground. A
pilot who is holding a good hover will suddenly start wobbling all over
as he gets near the ground. The problem is that people get concious of
the ground, and want to have a perfect hover in preparation for landing.
Just hold the best hover you can during the descent, and don't make any
special efforts as you touch down. Unless you are really bad at
hovering, this will give you a safer landing.
Not countering pitch and roll
Some pilots never learn to use the cyclic to counter pitch and roll during
the transition onto the skids. The result is sliding around on the parking
space, which is dangerous. Go out and practice your slope landings, both
parallel to the hill, and facing uphill (watch your tailrotor!) and you'll
be practicing the same elements required for landing on level ground. My
observation is that every takeoff and landing, even from a level area, is
really a slope takeoff and landing because of CG causing roll and pitch.
Landing next to another helicopter at low RPM
A pet peeve of mine. Helicopters are susceptible to rotor->airframe
contact while they are at low rotor RPM. They are at low rotor RPM during
startup and shutdown. Therefore, don't land next to a helicopter that is
just starting up, or has just shut down with it's blades still turning. If
you are about to pick up to a hover, don't do it if the pilot in the next
aircraft over is about to enage his rotors or has just killed his engine.
Wait until the other aircraft's rotors are either stopped, or are up to
operating RPM before you subject that aircraft to your downwash.
Proper orientation to land with respect to wind direction
Although it is certainly easier to land pointed into the wind, if the wind
is really strong or gusty you increase the chance of a tailboom strike
during shutdown or subsequent start up by landing into the wind. The
problem is that the rotor blade is flapping down and reaches maximum
downward deflection when it is over the tailboom when you land pointed
into the wind. Instead, if you either land tail into the wind (not such a
hot idea for a turbine aircraft) or with a cross wind, the blades will not
be at maximum down flap as they pass over the tailboom. Some manufacturers
recommend having the wind at your 7-8 o'clock position in this situation.
If you are an inexperienced pilot, you might not want to attempt tail into
the wind takeoffs and landings, since they are slightly more difficult to
perform. Hopefully an inexperienced pilot won't be flying on days where
the wind is strong enough to make boom strikes a concern..
paul at copters.com
(replace " at " with "@" to email me - this avoids SPAMMERS I hope)