Spencer Suderman - Play by Play Series - Inverted Flat Spin

[Scudrunner]

Just found this guys video's.

[Colonel]

Spencer is a great guy! He moved to Florida a couple years back,
and started playing for the other team (monoplanes).



He showed that Beggs-Mueller recovered at a higher altitude, than
positive spin recovery inputs. There's a lesson in there ....

[John Swallow]

Andrew:

I vaguely remember hearing something about Beggs/Mueller in the past: it may have been from you on a previous post. I googled it a few minutes ago and found this:

Do you agree with the responder?


The Beggs/Mueller technique is:

• engine idle
• let go of the stick
• push rudder against spin direction

This was developed for pilots of the Pitts Special biplane and will work well with naturally stable, powered aircraft. With gliders (where it strictly doesn't apply) it will be less effective, but still work in most cases. The better way is to combine both, rudder against the spin and stick forward (your PARE technique), but only until the rotation stops. Then both the stick and the rudder must be neutral until speed is sufficient for the pull-out. Beggs/Mueller is more about avoiding wrong inputs due to confusion than ending the spin in the most direct way.

Spin recovery with the hands off the stick will be slower than with active control input. If the control surfaces are free-floating, natural stability is normally less than what it is with fixed control surfaces. For that reason, the Beggs/Mueller technique is less effective than actively ending the spin with both rudder and elevator. If the pilot does not realize he is in an inverted spin, pushing down will make matters worse, however.

Why rudder against spin direction?

An aircraft spins because something stabilizes both the rotation and the high pitch angle. First the rotation: This is caused by fully separated airflow on the retreating wing while some section on the advancing wing has attached airflow. The high drag on the retreating wing pulls this side of the aircraft backwards, while the lift on the section of wing with attached airflow pulls that side of the aircraft forward. Remember, airflow is mostly coming from below, and the spin motion modifies the local flow direction the more one moves away from the center of the aircraft.

Why elevator forward (Back in inverted spin)?

Now the pitch angle: The center of rotation is ahead of the wing in the forward fuselage. The masses in the forward fuselage produce little centrifugal force, while the masses in the rear fuselage and the tail, having a substantial distance from the center of rotation, produce a substantial centrifugal force which pulls the whole aircraft into a level attitude. Since the aircraft's motion is mainly downward, this inertial moment increases the angle of attack above the stall angle.

To break the spin one needs to end the rotation or the pitch attitude. Since they mutually reinforce each other, one must be ended to end both. On aircraft with long fuselages the rudder is more effective to stop the rotation, while on aircraft with long wings the elevator will be more effective in ending the spin via reducing pitch attitude. The rotation is then stopped by the roll damping of the wing. Using both together will give the best effect, however.

Why engine to idle?

Having some added dynamic pressure on the vertical tail will also help to end the rotation, but then the aircraft will pick up speed very quickly. Setting the engine to idle will avoid falling into this particular trap, but again for the price of a somewhat slower recovery. Sometimes an aircraft needs that added dynamic pressure to end the rotation, so Beggs/Mueller will not work in all cases.

Source:

https://aviation.stackexchange.com/ques ... -technique

[Colonel]

Basic spin recovery:

Power off
Rudder opposite the yaw
Ailerons and elevator in trail (happens naturally, hands off)

Most people don't argue about the power off, and opposite rudder.
Stopping a spin for me, is about stopping the yaw, and that's rudder.

I am not a big fan of aileron usage in spin, because unless you really
know what you are doing - I don't know many people that good - you're
probably going to make things worse. 99.999% of pilots will try to
"pick up" a dropping wing with aileron in a stall, and the adverse yaw
of the down-going aileron makes things worse.



I am not a big fan of elevator usage in a spin, either. Forward stick in
an upright spin, for example, can blanket the rudder underneath the
elevator, which reduces it's effectiveness, and your ability to stop the
yaw (exit the spin).



It also can reduce the radius of gyration, and like a spinning skater in
one place pulling her arms in, conservation of momentum means that
you are going to rotate much faster. Probably only Photofly will get this,
but he damned well should, he has four degrees and a superb instructor
for his instructor rating:



Using the elevator in a spin is playing with fire. You may very well take
a gentle spin and accelerate it wildly.

The POH is golden, of course, and types vary. Beggs Mueller works
very well on a Pitts, but there are other common GA types that it does
not.

Some aircraft types and configurations (aft C of G) may require very
specific elevator inputs to recover from a spin. I recommend that
99.999% of pilots don't attempt that, because they aren't that good.

What I know about spins is that pilots often are very much behind the
aircraft and have no idea what is going on. I sit there quietly and watch
horrendous yaw, as they try all sorts of bizarre flight control inputs, and
allow the spin to accelerate into something really nasty, depending upon
what flight control inputs they use.

Pilots talking about spin recovery techniques puzzles me, because
pilots have great difficulty even recognizing a spin. There is an unusual
attitude guru - you would recognize his name - that does not understand
the difference between a spin and a snap roll, for example. He brags
about over-G'ing the aircraft that he instructs on, which means that he
is allowing much higher speeds to develop than necessary.

I enter and exit spins below 1,000 AGL. I instantly stop the spin before
it has a chance to wind up. That is why I am still alive. Observe:

www.pittspecials.com/movies/tumble.wmv

You can see why TC says that I am qualified but not eligible to renew
my class one instructor and class one aerobatic instructor ratings. I just
don't know very much about this stuff, I guess. It works out well that I
have left Canada permanently, which I understand is very important to TC.

[John Swallow]

Merci!

[Colonel]

Spin recovery is like getting a checkout on a C421, or learning plumbing.

There's a lot to it, but you can learn it all in one day:

1) cold goes on the right
2) poop runs downhill
3) payday is on Friday

[John Swallow]

As I remember, tumble recovery in the T-33 was a modification of Beggs-Mueller.

Let go of everything!

[Colonel]

I think I've mentioned that Dear Old Dad, when he was over in Europe flying Sabres,
developed an airshow routine in a T-bird that the base commander would have him
perform for visitors.

He loved to tumble the T-bird, because it would open the valves on the tip tanks
and spray fuel out. Very pretty.

[John Swallow]

THAT would have been impressive!