Thread: Discussion FPV landings
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Old Feb 04, 2010, 12:36 PM
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Practice practice practice..

That and knowing where your plane is going rather than paying attention to where
the nose is pointed. Realize that your view is a 2d representation of a 3d world
and use that to your advantage. Whenever the plane is flying and you're looking forward
there is some part of the screen where pixels appear to be moving "down",
and another where they appear to be moving "up". In between them is a point
that is not moving up or down, but just getting bigger (closer).
That point that is neither moving up or down, is where the plane is going.
That seems obvious but most people don't recognize that or use it. This is
true whether you can see the nose or not, whether the camera is angled up or
down a bit, whether the power is on or off, or you're at a high angle of attack.
The point that is not moving up or down in your view, is where the plane is going.

When you cut the power and let the airspeed drop until you're on a stable descent path
simply find that point in the frame, which is somewhere on the ground if you're descending,
that is not moving up or down and that's where you'll end up landing.
If that point is beyond your target LZ, then either do S-turns to burn up
the altitude quicker, or go around for another approach and start descent further
back or with less power. If you're coming in a little short then increase power just
enough to make that point that doesn't move rise a bit in the frame and then just
hold steady low power on that path until you intersect where you want to.

Practice just doing descents and finding that non-moving point in the frame and
trying to place it on the ground where you want to land without actually landing.
And if you have a tight LZ surrounded by trees, don't make your approach flying
straight and level over the trees. Start higher and further back and adjust
your descent to put the non-moving point right at the tops of the trees.
You want to be on a low airspeed, high angle descent that causes you to just clear
the tips of the trees and continue down at the same rate to the ground.
The problem with coming in level over the trees is that you'll likely have
too much airspeed because you need to fly faster to stay level. You
chop the throttle and it takes time to establish a stable descent and you end up
running long of the LZ.

Another way to deal with a line of trees is to come at it parallel. Come in
parallel and close to the trees on the LZ side, 90 degrees from your final approach,
descend until you're actually below the tops of the trees, and then make a tight 90
degree turn onto final which will burn up some more altitude and drop you where you
want to be.

Lastly, learn how to fly a conventional landing pattern.
Downwind (not always downwind, but is always opposite direction as final), base, final.

Establish your decent rate on the downwind leg. Turn 90 degrees to base
when you feel as though the combination of the distance of base and final will put
you where you want. If you're high on downwind, then just go further before turning
to base and final. That way you're not trying to make all your airspeed and decent
angle decisions on final (as many people do). Realize also that if you are
flying a true downwind leg and final is upwind, that you're effective descent angle
will increase as you turn to final, because your ground speed will decrease.
That means you can be a little high on downwind and base and
still drop it in on final. Or you know you can fly downwind and base as though
there is no wind, and then increase power slightly on final to decrease descent
rate to get you to the LZ.

While I fly planes with power, virtually all my landings are dead stick. I rarely
land more than 50-100 feet from my base station. One advantage to always
gliding in for a landing is that you generally *will not* stall once a stable descent
is established. Many people stall because they're trying to fly level or at
too low a decent rate for the given power. They're trying to pull up
to go up instead of powering up to go up. If you take away the power
then there's no ambiguity about what the descent rate needs to be. Then just
adjust approach pattern to make it longer or shorter until you intersect the
ground where you want.

BTW, Flaperons on EZG or similar are not a great idea. It'll reduce
aileron effectiveness and increase chance of tip stalls.
Spoilerons (both ailerons up) is more useful. You won't tip stall, and it will increase
your descent rate when you need it.

ian
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