Power-out spot landing techniques?

"Cub Driver" wrote in message
...

Don't you lose the "dirty spot" when you're slipping?

My last 3-axis airplane didn't have a windsheild, so there was no dirty spot
to lose . Just kept my eyes on the landing spot and kept it from moving,
whether I was in a slip or not....

LS
AC fun racer 503.

all the best -- Dan Ford
email: www.danford.net/letters.htm#9

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

ls wrote:

The cheezy way to do it is to just dive a bit until the
glideslope flattens a bit and then resume your approach airspeed (although
not cheezy in my aircraft type which is incapable of slips - that's pretty
much my only option). Don't do this on the checkride or even with the CFI
on board - they'll slap you upside the head and with good reason. The much
better way is to use a slip or, if you're sure you have it made, adding
flaps, to accellerate energy dissipation and get you on glideslope without
building up too much airspeed.

What about slowing below best glide, but (obviously {8^) above stall?


If, on the other hand, you're having to hold too low of an airspeed to
keep the landing point from moving up, you don't have enough energy to
make it there and you're going to come up short.

This I don't follow. If the spot is steady, you're going to make the spot
at your current speed (assuming you're holding that speed, of course).

- Andrew

A previous poster mentioned airspeed, and he's right. Most of the
students I fly with have trouble nailing an airpseed and holding it.
For power-off approaches, use the best glide speed and then make
the approach just a bit high, applying flap as necessary to steepen
the glide to hit the spot. You can also reduce the approach speed a
bit to steepen a glide, but watch that you don't start such a serious
sink rate that you end up short without any flare speed. Reducing
glide speed 5 knots can make a big difference in the glide angle.
Diving at the spot is the wrong thing to do, as it increases airspeed
which will only cause float when you reach the surface.
I once read of the British training their recon pilots in spot
landings during the big war. They buried a 2x6 flush with the grass,
flat side up, and the pilots learned to touch down ON the board, in
that 5 1/2 inches, without bouncing and at a given airspeed. If they
could do it, so can we. We just don't care enough to get good at it.
Or, perhaps, we can't afford to get good at it.

Dan

(Dan Thomas) writes:

Reducing glide speed 5 knots can make a big difference in the glide
angle. Diving at the spot is the wrong thing to do, as it increases
airspeed which will only cause float when you reach the surface.

And that's only half the problem: at the higher speed, you also close
with the threshold sooner, so there's less time for the plane to
descend. 700 fpm is 700 ft/nm at 60 kt, but only 525 ft/nm at 80 kt.
If you start two miles back even with no wind, you'll end up 350 ft
higher over the threshold with the 80 kt dive than you would with the
60 kt mush.


All the best,


David

--
David Megginson, , http://www.megginson.com/

David Megginson wrote:

And that's only half the problem: at the higher speed, you also close
with the threshold sooner, so there's less time for the plane to
descend. 700 fpm is 700 ft/nm at 60 kt, but only 525 ft/nm at 80 kt.

Ever heard of such a thing as a polar curve?

Stefan

David Megginson wrote:

And that's only half the problem: at the higher speed, you also close
with the threshold sooner, so there's less time for the plane to
descend. 700 fpm is 700 ft/nm at 60 kt, but only 525 ft/nm at 80 kt.

Ever heard of such a thing as a polar curve?

Stefan



..

David Megginson wrote:

And that's only half the problem: at the higher speed, you also close
with the threshold sooner, so there's less time for the plane to
descend. 700 fpm is 700 ft/nm at 60 kt, but only 525 ft/nm at 80 kt.

Ever heard of such a thing as a polar curve?

Stefan



..

Stefan "stefan"@mus. INVALID .ch writes:

And that's only half the problem: at the higher speed, you also close
with the threshold sooner, so there's less time for the plane to
descend. 700 fpm is 700 ft/nm at 60 kt, but only 525 ft/nm at 80 kt.

Ever heard of such a thing as a polar curve?

Details, please.


All the best,


David

--
David Megginson, , http://www.megginson.com/

David Megginson wrote:

Ever heard of such a thing as a polar curve?

Details, please.

e.g. http://home.att.net/~jdburch/polar.htm

I'm sure an internet search will yield a lot of others.

Stefan

(Richard Thomas) wrote in message ...
My instructor has me doing power out simulted emergency spot landings
in prep for my checkride. I've already had my checkride put back once
cause I'm not getting them right often enough. Did some more today but
still not 100%.

Does anyone ahve any tips? He wants me to land on the numbers. I can
sometimes do it 2 or 3 times in a row but next time, I'll be 100 ft
too high or just a little too low

A power off approach to touch down "on the numbers" is a commercial
maneuver called a 180 precision approach. For private you just want to
be about 1/3 of the way down the runway. However, its up to your CFI.
I find that students have the most trouble doing engine outs from
cruise altitudes, so I usually end air work (stalls, slow flight, etc)
by pulling the engine and we go for an off field landing. There really
is only one "trick" necessary and if you can understand it, everything
about your landings will get better. When you are approaching a
landing spot there is one spot that does not move in your field of
vision. If you were writing a filght simulator program, you'd need to
make everything above and below this magic point "stretch" because
that's what happends in real life. The area that does not move is
where you will be if you don't touch anything. Once you can see that
point you can predict where you will touch down and can correct. Also,
I teach to come in high and do a lot of slipping. I also take students
out and just practice slipping because it makes engine out landings
so, so , so much easier because you can so greatly control your rate
of decent. It also makes tailwheel transition easier.

-Robert, CFI