Dumb question maybe re Stall Turn

Need someone to settle an argument. I do not fly, so your answers need
to be in laymans terms and hopefully put simply.
I've occasionally watched aerobatic displays and seen a maneouver
called a stall turn. Now, I more or less understand how this works,
but there comes a point, just before the aircraft "turns around" where
it is momentarily stationary in space, pointing directly to the sky..
Impressive stuff. Now, here's the crux: My mate reckons the pilot
could hold the aircraft in this "head-up" attitude almost indefinately
as the prop is acting like a helicopter's rotor and it could
effectively hover in this attitude. I, however, maintain that the
aircraft would begin to spin on it's axis if held in this attitude.for
more than a second or two.

Can anybody tell me who is correct?

Thanks all,

Roy

In article
,
Surreyrider wrote:

Need someone to settle an argument. I do not fly, so your answers need
to be in laymans terms and hopefully put simply.
I've occasionally watched aerobatic displays and seen a maneouver
called a stall turn. Now, I more or less understand how this works,
but there comes a point, just before the aircraft "turns around" where
it is momentarily stationary in space, pointing directly to the sky..
Impressive stuff. Now, here's the crux: My mate reckons the pilot
could hold the aircraft in this "head-up" attitude almost indefinately
as the prop is acting like a helicopter's rotor and it could
effectively hover in this attitude. I, however, maintain that the
aircraft would begin to spin on it's axis if held in this attitude.for
more than a second or two.

Can anybody tell me who is correct?

Thanks all,

Roy

It all depends on the aircraft. Planes with a very high thrust:weight
ratio could do so, if they have the control authority. Problem is -- at
zero airspeed, neither stick nor rudder-controlled surfaces have any
authority, as they depend on airspeed to make them work.

The maneuver you describe is the "tail slide," where the engine is the
only control left and the plane starts to roll due to torque.

You are correct about the rolling torque.

--
Remove _'s from email address to talk to me.

That's not a stall turn, or a tail slide, that's the old gyro-hang
you're on about there. Both the stall turn and the tailslide could of
course be stopped just before the turn or the slide by doing the hang.
Eventually, and I mean eventually, the plane might start to spin, once
the torque had overcome the intertia, but as Orval says it depends on
the weight of the plane and the power output of the engine, which for
the gyro-hang is quite low (or you'd just climb). You could keep it up
for maybe a minute without too many problems.

Hope that answers your question!




On Nov 18, 6:06*pm, Surreyrider wrote:
Need someone to settle an argument. I do not fly, so your answers need
to be in laymans terms and hopefully put simply.
I've occasionally watched aerobatic displays and seen a maneouver
called a stall turn. *Now, I more or less understand how this works,
but there comes a point, just before the aircraft "turns around" where
it is momentarily stationary in space, pointing directly to the sky..
Impressive stuff. *Now, here's the crux: *My mate reckons the pilot
could hold the aircraft in this "head-up" attitude almost indefinately
as the prop is acting like a helicopter's rotor and it could
effectively hover in this attitude. *I, however, maintain that the
aircraft would begin to spin on it's axis if held in this attitude.for
more than a second or two.

Can anybody tell me who is correct?

Thanks all,

Roy

Your friend is correct. The torque produced by helicopter rotors is
proportional to their length - just as if you were to use a wrench on
a nut with a very long shaft, the longer the shaft the greater the
torque. I assume you are talking of a single prop engine stunt plane?
These are light and the thrust needed to maintain a static hover as
you describe is not great, and coupled with the short rotor length the
torque produced would not necessarily overcome the inertia of the
plane

On Nov 18, 6:06*pm, Surreyrider wrote:
Need someone to settle an argument. I do not fly, so your answers need
to be in laymans terms and hopefully put simply.
I've occasionally watched aerobatic displays and seen a maneouver
called a stall turn. *Now, I more or less understand how this works,
but there comes a point, just before the aircraft "turns around" where
it is momentarily stationary in space, pointing directly to the sky..
Impressive stuff. *Now, here's the crux: *My mate reckons the pilot
could hold the aircraft in this "head-up" attitude almost indefinately
as the prop is acting like a helicopter's rotor and it could
effectively hover in this attitude. *I, however, maintain that the
aircraft would begin to spin on it's axis if held in this attitude.for
more than a second or two.

Can anybody tell me who is correct?

Thanks all,

Roy

On Wed, 18 Nov 2009 10:06:09 -0800 (PST), Surreyrider
wrote:

Need someone to settle an argument. I do not fly, so your answers need
to be in laymans terms and hopefully put simply.
I've occasionally watched aerobatic displays and seen a maneouver
called a stall turn. Now, I more or less understand how this works,
but there comes a point, just before the aircraft "turns around" where
it is momentarily stationary in space, pointing directly to the sky..
Impressive stuff. Now, here's the crux: My mate reckons the pilot
could hold the aircraft in this "head-up" attitude almost indefinately
as the prop is acting like a helicopter's rotor and it could
effectively hover in this attitude. I, however, maintain that the
aircraft would begin to spin on it's axis if held in this attitude.for
more than a second or two.

Can anybody tell me who is correct?

Thanks all,

Roy
Roy, I have only performed the stall turn or hammerhead in a couple of
aircraft, a Decathlon and my Jungster II, both with 150 hp. It has
been my experience that you had better kick rudder before the aircraft
stops or you will experience the thrill of a tailslided and a whip
stall. You can tell when you are about to run out of steam by watching
your wing tip, that also keeps the ship from rotating. I always pick a
road intersection so I can keep the wings aligned with the crossroad.
Neither of these aircraft had the poop to hang on the prop.
Ed Sullivan

"Surreyrider" wrote in message
...
Need someone to settle an argument. I do not fly, so your answers need
to be in laymans terms and hopefully put simply.
I've occasionally watched aerobatic displays and seen a maneouver
called a stall turn. Now, I more or less understand how this works,
but there comes a point, just before the aircraft "turns around" where
it is momentarily stationary in space, pointing directly to the sky..
Impressive stuff. Now, here's the crux: My mate reckons the pilot
could hold the aircraft in this "head-up" attitude almost indefinately
as the prop is acting like a helicopter's rotor and it could
effectively hover in this attitude. I, however, maintain that the
aircraft would begin to spin on it's axis if held in this attitude.for
more than a second or two.

Can anybody tell me who is correct?

Thanks all,

Roy

You need two things to make it work. More power (thrust) than 99.9% of the
(full scale) aircraft out there, and ailerons that extend all the way to
the wing root to keep it from rolling.

It's done by a few airshow pilots and is reasonably common in the radio
control aircraft crowd. You could probably find some RC examples on youtube
with minimal effort.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.