bouncing off the runway

Yesterday I chatted with a retired man flying a model airplane. He said
he'd taken lessons in a plane with conventional gear in the 1950s. On
his third lesson, the instructor had him land. It was perfect.

After that, every time he landed he would bounce and float above the
runway. His instructor didn't know what caused it. A senior instructor
went up with him and observed that when he touched down, he didn't
continue to hold the stick back. That caused the tail to rise and the
plane to lift off.

That doesn't make sense to me. I've always understood that with
conventional gear, excess speed is the cause of bouncing and floating.
With the main wheels forward of the center of mass, your angle of attack
will increase when you touch down, and the plane will rise if you still
have flying speed.

If a pilot touches down too fast, I've understood that he needs to keep
the tail up and use the brakes without nosing over.

If the instructor had told him he was touching down too fast because he
wasn't holding the stick back far enough during descent, that would make
sense to me because a higher angle of attack induces more drag.

The man said the problem was that he had failed to keep the stick back
after touchdown. Does his recollection make sense?

On Jun 26, 3:00*pm, E Z Peaces wrote:


The man said the problem was that he had failed to keep the stick back
after touchdown. *Does his recollection make sense?

Nope

Cheers

E Z Peaces wrote in news:g3v0og$d61$1
@registered.motzarella.org:

Yesterday I chatted with a retired man flying a model airplane. He said
he'd taken lessons in a plane with conventional gear in the 1950s. On
his third lesson, the instructor had him land. It was perfect.

After that, every time he landed he would bounce and float above the
runway. His instructor didn't know what caused it. A senior instructor
went up with him and observed that when he touched down, he didn't
continue to hold the stick back. That caused the tail to rise and the
plane to lift off.

That doesn't make sense to me. I've always understood that with
conventional gear, excess speed is the cause of bouncing and floating.
With the main wheels forward of the center of mass, your angle of attack
will increase when you touch down, and the plane will rise if you still
have flying speed.

If a pilot touches down too fast, I've understood that he needs to keep
the tail up and use the brakes without nosing over.

If the instructor had told him he was touching down too fast because he
wasn't holding the stick back far enough during descent, that would make
sense to me because a higher angle of attack induces more drag.

The man said the problem was that he had failed to keep the stick back
after touchdown. Does his recollection make sense?



Yep.

Bertie

More_Flaps wrote in news:0390ffd1-a85e-4ae3-8971-
:

On Jun 26, 3:00*pm, E Z Peaces wrote:


The man said the problem was that he had failed to keep the stick back
after touchdown. *Does his recollection make sense?

Nope



Does actually. Little tailfraggers, and big ones, come to think of it,
bounce along of you dont get the stick back after three pointing. the mains
will thrust it back up into the air a bit and then the nose comes back down
again repeating the cycle.



Bertie

On Jun 25, 8:00*pm, E Z Peaces wrote:
Yesterday I chatted with a retired man flying a model airplane. *He said
he'd taken lessons in a plane with conventional gear in the 1950s. *On
his third lesson, the instructor had him land. *It was perfect.

After that, every time he landed he would bounce and float above the
runway. *His instructor didn't know what caused it. *A senior instructor
* went up with him and observed that when he touched down, he didn't
continue to hold the stick back. *That caused the tail to rise and the
plane to lift off.

That doesn't make sense to me. *I've always understood that with
conventional gear, excess speed is the cause of bouncing and floating.
With the main wheels forward of the center of mass, your angle of attack
will increase when you touch down, and the plane will rise if you still
have flying speed.

You have to hold the stick back until you tie the plane down in order
to plant the little tailwheel on the ground. Without the stick back
not only do you have less steering but because it has so little weight
it could easily pop back up (if you push the stick forward right after
landing you could pop it up easily). In most light taildraggers one
person can easily lift the tail off the ground (which is how we would
move the plane, no tow bar required).

-Robert

Bertie the Bunyip wrote:
More_Flaps wrote in news:0390ffd1-a85e-4ae3-8971-
:

On Jun 26, 3:00 pm, E Z Peaces wrote:

The man said the problem was that he had failed to keep the stick back
after touchdown. Does his recollection make sense?
Nope



Does actually. Little tailfraggers, and big ones, come to think of it,
bounce along of you dont get the stick back after three pointing. the mains
will thrust it back up into the air a bit and then the nose comes back down
again repeating the cycle.



Bertie

Doesn't a three-point landing occur at stall speed? Isn't the plane
going too slowly to lift off again? Besides, if the tail is that low,
touching down won't increase the angle of attack, will it?

You say the mains will thrust it back up into the air and the cycle will
repeat. In a three-point landing, it seems it would take springs to make
a plane rise. Aren't shock absorbers supposed to prevent that?

Bertie the Bunyip wrote:
More_Flaps wrote in news:0390ffd1-a85e-4ae3-8971-
:

On Jun 26, 3:00 pm, E Z Peaces wrote:

The man said the problem was that he had failed to keep the stick back
after touchdown. Does his recollection make sense?
Nope



Does actually. Little tailfraggers, and big ones, come to think of it,
bounce along of you dont get the stick back after three pointing. the mains
will thrust it back up into the air a bit and then the nose comes back down
again repeating the cycle.



Bertie


Doesn't a three-point landing occur at stall speed? Isn't the plane
going too slowly to lift off again? Besides, if the tail is that low,
touching down won't increase the angle of attack, will it?

You say the mains will thrust it back up into the air and the cycle will
repeat. In a three-point landing, it seems it would take springs to make
a plane rise. Aren't shock absorbers supposed to prevent that?

Bertie the Bunyip wrote:
More_Flaps wrote in news:0390ffd1-a85e-4ae3-8971-
:

On Jun 26, 3:00 pm, E Z Peaces wrote:

The man said the problem was that he had failed to keep the stick back
after touchdown. Does his recollection make sense?
Nope



Does actually. Little tailfraggers, and big ones, come to think of it,
bounce along of you dont get the stick back after three pointing. the mains
will thrust it back up into the air a bit and then the nose comes back down
again repeating the cycle.



Bertie

Doesn't a three-point landing occur at stall speed? Isn't the plane
going too slowly to lift off again? Besides, if the tail is that low,
touching down won't increase the angle of attack, will it?

You say the mains will thrust it back up into the air and the cycle will
repeat. In a three-point landing, it seems it would take springs to make
a plane rise. Aren't shock absorbers supposed to prevent that?

E Z Peaces wrote in
:

Bertie the Bunyip wrote:
More_Flaps wrote in
news:0390ffd1-a85e-4ae3-8971-
:

On Jun 26, 3:00 pm, E Z Peaces wrote:

The man said the problem was that he had failed to keep the stick
back after touchdown. Does his recollection make sense?
Nope



Does actually. Little tailfraggers, and big ones, come to think of
it, bounce along of you dont get the stick back after three pointing.
the mains will thrust it back up into the air a bit and then the nose
comes back down again repeating the cycle.



Bertie

Doesn't a three-point landing occur at stall speed?


Not always.


Isn't the plane
going too slowly to lift off again? Besides, if the tail is that low,
touching down won't increase the angle of attack, will it?

If the tail is that low, you have th estick all the way back.


You say the mains will thrust it back up into the air and the cycle
will repeat. In a three-point landing, it seems it would take springs
to make a plane rise. Aren't shock absorbers supposed to prevent
that?


Shock absorbers are for cars and they'r emade to dampen cycles such as
that.




Bertie

On Jun 26, 7:25*am, E Z Peaces wrote:

Doesn't a three-point landing occur at stall speed? *

That is one of the biggest myths in aviation. I've flown a lot of
taildraggers (GA) and few of them had the stall angle and the 3 pt
angle in alignment. As an example the Globe Swift stalls with the tail
about 2 feet off the ground while the Decathlon/Citabria stalls with
the tail on the ground and the mains still several feet in the air,
its very, very much still flying in the 3pt position. The hard part of
landing a Citabria is not to crush the mains after landing the tail.

-Robert, CFII