Conventional v tricycle gear

On Jul 9, 9:26 pm, wrote:
On Jul 9, 1:24 pm, Bertie the Bunyip wrote:

I still don't see it shortening the landing roll. Can't see the physics that
would make a wheel landing shorter. I'll just have to try it!

Here are the physics:

The trike, to get maximum weight on its mains for braking
traction, has to keep its weight off the nose. We can use full up-
elevator, but the presence of the nosewheel assures us that it will
take some of the weight and that we cannot get the wing's AOA low
enough to stop it lifting. The only advantage we have in the trike is
the elevator's downforce added to the airplane's weight. Electric flas
make it worse, since we can't retract them instantly to dump their
lift.

The taildragger can get its tail way up high. If you sit in the
airplane while its tail is on a jack or some other support so that the
airplane is in level attitude, you will be astounded at how nose-low
it feels. Observe the propeller clearance in this position, too, and
make some allowance for bouncing that might lower the prop closer to
the runway. I used to do this with students who were afraid to raise
the tail to level attitude, and they always amazed at the picture out
the front.
A taildragger with long legs, like a 185, can get its tail even
higher than level. I've seen a shot of a Helio Courier with its tail
up so that the fuselage was pointed downward at 5 or 10 degrees, and
the pilot was braking hard. No lift at all in that scenario, and
manual flaps can be retracted quickly to get even more weight on the
wheels. Most taildraggers will have the main axles 15 degrees ahead of
the airplane's CG, meaning that if you pick up the tail you can raise
it until the airplane is at that 15 degree nose-low attitude and it
will be balanced there. You'd better have lots of skill if you're
going to try this in the rollout. Pilots of another humanitarian
outfit that operated Helios did this all the time, since the Helio's
short-field takeoff capabilities are of no use if you can't get into
that short little strip and get stopped in the first place.

Dan

You'd better go try a few. It works, believe me.

Dan

wrote in
:

On Jul 9, 9:26 pm, wrote:
On Jul 9, 1:24 pm, Bertie the Bunyip wrote:

I still don't see it shortening the landing roll. Can't see the
physics that would make a wheel landing shorter. I'll just have to
try it!

Here are the physics:

The trike, to get maximum weight on its mains for braking
traction, has to keep its weight off the nose. We can use full up-
elevator, but the presence of the nosewheel assures us that it will
take some of the weight and that we cannot get the wing's AOA low
enough to stop it lifting. The only advantage we have in the trike is
the elevator's downforce added to the airplane's weight. Electric
flas make it worse, since we can't retract them instantly to dump
their lift.

The taildragger can get its tail way up high. If you sit in the
airplane while its tail is on a jack or some other support so that
the airplane is in level attitude, you will be astounded at how
nose-low it feels. Observe the propeller clearance in this position,
too, and make some allowance for bouncing that might lower the prop
closer to the runway. I used to do this with students who were afraid
to raise the tail to level attitude, and they always amazed at the
picture out the front.
A taildragger with long legs, like a 185, can get its tail even
higher than level. I've seen a shot of a Helio Courier with its tail
up so that the fuselage was pointed downward at 5 or 10 degrees, and
the pilot was braking hard. No lift at all in that scenario, and
manual flaps can be retracted quickly to get even more weight on the
wheels. Most taildraggers will have the main axles 15 degrees ahead
of the airplane's CG, meaning that if you pick up the tail you can
raise it until the airplane is at that 15 degree nose-low attitude
and it will be balanced there. You'd better have lots of skill if
you're going to try this in the rollout. Pilots of another
humanitarian outfit that operated Helios did this all the time, since
the Helio's short-field takeoff capabilities are of no use if you
can't get into that short little strip and get stopped in the first
place.

Dan

You'd better go try a few. It works, believe me.


I will. I have done some very short field stuff and your's wouldn't be a
technique that would appeal! I'm going to try it if I ever get this
damned airplane flying, though..