This maneuver is used to transition from forward flight to a hover or
a landing when a normal 10 degree approach will not clear obstacles.
We usually consider a normal approach to be a 10 degree approach. More
than 10 degrees is considered to be a "steep" approach. You can fly any
steep angle you have the power for, up to 90 degrees. However, for the
purposes of teaching we use 15 degrees as a "steep" approach.
The maneuver is similar to a normal approach except that at a given
altitude you will intercept the 15 degree approach angle closer to your
landing area than you would while intercepting a shallower angle. This
typically requires a slightly more aggressive decelleration than for
a normal approach, since you have to get rid of the same amount of airspeed,
but over a shorter distance.
You will also notice that the collective will initially have to be at
a lower position than for a normal aproach, and you will be holding
more right pedal as well.
The approach and deceleration are exactly the same as for a normal
approach, simply at a steeper angle. The controls are manipulated
the same as during a normal approach.
The next big difference you will notice is that you will be at a higher
altitude when losing translational lift than during a normal approach.
This will require more power than a normal approach would, and needs to
be included in your pre-approach planning.
Settling with Power
The steeper the approach is, the more likely the pilot is to encounter settling with power. Remember that
descent rate should be below 300 feet per minute before you lose
ETL (Effective Translational Lift).
A common mistake people make is to keep their airspeed high in an attempt
to avoid settling with power. This actually makes things worse, since your
descent rate is dependent on your ground speed. A higher airspeed means a
higher ground speed, means a higher descent rate. You are actually much
better to fly a slow approach in order to keep your descent rate low. The
key is to make sure you decrease your descent rate below 300 feet per minute
before you slow below ETL.
Failure to maintain approach angle
Until the pilot can judge approach angle accurately, he may deviate from
approach angle and not realize it. While overshooting onto steeper angles
certainly occurs, the more common problem is failure to increase power
to account for the back side of the power curve. Especially below 40 knot,
the power required increases quickly, and the pilot may simply not raise
collective fast enough. If you are using a steep approach to clear obstacles,
a descent below approach angle may settle you into the obstacle you are trying
to avoid. Therefore it is important to immediately counter any tendency to
settle with immediate application of power. This also will help prevent an
entry into settling with power if airspeed is below ETL.
Failure to decelerate properly
A common mistake is to have too much air/ground speed on short final
during a steep approach. This is caused by a number of things: less time
to decelerate, higher altitude above terrain making the speed seem
slower, fear of an engine failure. This tendency toward high speed needs
to be fought. It is much better to be a little slow and have to add a little
extra power to maintain altitude, than it is to be fast and have to flare.
A steep approach is being used because of obstacle clearance concerns, and
a flare drops your tail rotor right into the obstacles you are trying to
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