Flat Spin

I'm surprised this spin thread hasn't produced more discussion of the flat
spin. One poster told us about getting into a flat spin after several
revolutions of a "normal" spin" at Minden when the Puch went flat (nose on
horizon). The poster thought it was kind of thrilling, until he applied spin
recovery controls (opposite rudder & forward stick) The Puch continued to flat
spin for another 5 or 6 revolutions. This spin started at 12,000 feet. Had it
been initiated at a much lower altitude, we might be investigating yet another
Puch-in. Has anyone else had the Puch go into a flat spin?

Perhaps those who have are no longer with us?
JJ Sinclair

I wonder where the CG was for the "Puch Flat Spin"

BT

"JJ Sinclair" wrote in message
...
I'm surprised this spin thread hasn't produced more discussion of the flat
spin. One poster told us about getting into a flat spin after several
revolutions of a "normal" spin" at Minden when the Puch went flat (nose on
horizon). The poster thought it was kind of thrilling, until he applied
spin
recovery controls (opposite rudder & forward stick) The Puch continued to
flat
spin for another 5 or 6 revolutions. This spin started at 12,000 feet. Had
it
been initiated at a much lower altitude, we might be investigating yet
another
Puch-in. Has anyone else had the Puch go into a flat spin?

Perhaps those who have are no longer with us?
JJ Sinclair

(JJ Sinclair) wrote in message ...
I'm surprised this spin thread hasn't produced more discussion of the flat
spin. One poster told us about getting into a flat spin after several
revolutions of a "normal" spin" at Minden when the Puch went flat (nose on
horizon). The poster thought it was kind of thrilling, until he applied spin
recovery controls (opposite rudder & forward stick) The Puch continued to flat
spin for another 5 or 6 revolutions. This spin started at 12,000 feet. Had it
been initiated at a much lower altitude, we might be investigating yet another
Puch-in. Has anyone else had the Puch go into a flat spin?

Perhaps those who have are no longer with us?
JJ Sinclair



Group,

As a Pitts owner and pilot who flies a LOT of aerobatics I thought I
would chime in on a possible reason for the Puchs' delayed recovery
from the flat spin.

The quickest and most assured method of exiting a flat spin is to
first convert it to a conventional spin and then exit that spin mode.

In a Pitts you get the spin to go flat by adding opposite aileron.
Take away the the opposite aileron and it returns to a conventional
spin. The puch most likely flatens out the same way.

More than one Pitts pilot has pounded in while trying to exit a flat
spin before first converting it to a conventional spin. This delay in
recovery from a flat spin could find you establishing a new bottom to
the aerobatic box.

It is therefore imperative to not add opposite aileron while spinning
(in an attempt to pick up the low wing) or risk having it go flat. If
you do find yourself in a developed flat spin you need to confirm that
you have not added opposite aileron and/or add a little pro-spin
aileron to assist in returning the aircraft to a conventional spin and
then recover from that spin mode.

All that said, I must also add that I have never flown the Puch. All
the above is based on aerobatics in a Pitts. I am not a CFIG or the
current world aerobatic champ. This is information that my CFIG has
instilled in me and is supported by many books on aerobatics that I
have read. It has also been proven to myself time and time again in
practical application.

Anybody up for a discussion on inverted accelerated flat spins?!

Gus Rasch
Pitts S1S
N21JF

Great information, Gus!

Many models of sailplane require holding opposite aileron to maintain
the spin, otherwise it transitions into a spiral dive. It is very
possible that Puchacz pilots are doing exactly this, then returning
the ailerons to neutral to perform a normal recovery after the spin
goes flat. Your suggestion, then, is to put the the stick into the
inside wing (raise the aileron on the higher drag wingtip) and pause
as a precursor to initiating normal spin recovery?

Another question for you...

Do your aerobatics texts discuss the suitability of different
types/models of aircraft for aerobatics? Are there models that are
suitably stressed, but not ideal because of control issues (too
little, too much...)?

(Gus Rasch) wrote in message . com...
(JJ Sinclair) wrote in message ...
I'm surprised this spin thread hasn't produced more discussion of the flat
spin. One poster told us about getting into a flat spin after several
revolutions of a "normal" spin" at Minden when the Puch went flat (nose on
horizon). The poster thought it was kind of thrilling, until he applied spin
recovery controls (opposite rudder & forward stick) The Puch continued to flat
spin for another 5 or 6 revolutions. This spin started at 12,000 feet. Had it
been initiated at a much lower altitude, we might be investigating yet another
Puch-in. Has anyone else had the Puch go into a flat spin?

Perhaps those who have are no longer with us?
JJ Sinclair



Group,

As a Pitts owner and pilot who flies a LOT of aerobatics I thought I
would chime in on a possible reason for the Puchs' delayed recovery
from the flat spin.

The quickest and most assured method of exiting a flat spin is to
first convert it to a conventional spin and then exit that spin mode.

In a Pitts you get the spin to go flat by adding opposite aileron.
Take away the the opposite aileron and it returns to a conventional
spin. The puch most likely flatens out the same way.

More than one Pitts pilot has pounded in while trying to exit a flat
spin before first converting it to a conventional spin. This delay in
recovery from a flat spin could find you establishing a new bottom to
the aerobatic box.

It is therefore imperative to not add opposite aileron while spinning
(in an attempt to pick up the low wing) or risk having it go flat. If
you do find yourself in a developed flat spin you need to confirm that
you have not added opposite aileron and/or add a little pro-spin
aileron to assist in returning the aircraft to a conventional spin and
then recover from that spin mode.

All that said, I must also add that I have never flown the Puch. All
the above is based on aerobatics in a Pitts. I am not a CFIG or the
current world aerobatic champ. This is information that my CFIG has
instilled in me and is supported by many books on aerobatics that I
have read. It has also been proven to myself time and time again in
practical application.

Anybody up for a discussion on inverted accelerated flat spins?!

Gus Rasch
Pitts S1S
N21JF

On 5 Feb 2004 18:57:40 -0800, (Gus Rasch)
wrote:

(JJ Sinclair) wrote in message ...
I'm surprised this spin thread hasn't produced more discussion of the flat
spin. One poster told us about getting into a flat spin after several
revolutions of a "normal" spin" at Minden when the Puch went flat (nose on
horizon). The poster thought it was kind of thrilling, until he applied spin
recovery controls (opposite rudder & forward stick) The Puch continued to flat
spin for another 5 or 6 revolutions. This spin started at 12,000 feet. Had it
been initiated at a much lower altitude, we might be investigating yet another
Puch-in. Has anyone else had the Puch go into a flat spin?

Perhaps those who have are no longer with us?
JJ Sinclair



Group,

As a Pitts owner and pilot who flies a LOT of aerobatics I thought I
would chime in on a possible reason for the Puchs' delayed recovery
from the flat spin.

The quickest and most assured method of exiting a flat spin is to
first convert it to a conventional spin and then exit that spin mode.

In a Pitts you get the spin to go flat by adding opposite aileron.
Take away the the opposite aileron and it returns to a conventional
spin. The puch most likely flatens out the same way.

More than one Pitts pilot has pounded in while trying to exit a flat
spin before first converting it to a conventional spin. This delay in
recovery from a flat spin could find you establishing a new bottom to
the aerobatic box.

It is therefore imperative to not add opposite aileron while spinning
(in an attempt to pick up the low wing) or risk having it go flat. If
you do find yourself in a developed flat spin you need to confirm that
you have not added opposite aileron and/or add a little pro-spin
aileron to assist in returning the aircraft to a conventional spin and
then recover from that spin mode.

All that said, I must also add that I have never flown the Puch. All
the above is based on aerobatics in a Pitts. I am not a CFIG or the
current world aerobatic champ. This is information that my CFIG has
instilled in me and is supported by many books on aerobatics that I
have read. It has also been proven to myself time and time again in
practical application.

Anybody up for a discussion on inverted accelerated flat spins?!

Gus Rasch
Pitts S1S
N21JF


On my spin flight in the S2A we got to accelerated flat spins upright.
I thought that was thrilling enough.
Your point about the in and out spin aleron is well made and this is
something that you can demonstrate easily in a Pitts and which I had
never seen in a glider althoght knew about it.

Had an interesting discussion with that instructor yesterday about all
this spinning stuff. He has a lot of time in gliders too. We are both
of the opinion that full spin training is best done in powered
aircraft with professional instructor.

Mike Borgelt

"The Puch continued to flat
spin for another 5 or 6 revolutions. This spin started at 12,000 feet. =
Had it
been initiated at a much lower altitude, we might be investigating yet =
another
Puch-in."
Rather unlkely scenario as you are not taking account of air =
density/Reynolds number.
My experience of extensive spinning in the SZD30 Puchacz is that at =
altitudes in excess of 8,000 feet the spin recovery is prolonged =
regardless of spin characteristics. If "out spin" aileron is applied the =
spin tends to go flat and the rotation apparently decreases. If "in =
spin" aileron is applied the spin goes nose down and appears to increase =
in rate of rotation. Standard recovery action results in both types of =
spin stopping after three to 5 turns - remember that part of the =
recovery procedure is "centralise ailerons".
Below 5,000 feet the SZD30 tends to cease spinning if the back pressure =
on the stick is simply relaxed, i.e. without application of out spin =
rudder.
The difference is nothing to do with C of G position or aircraft =
configuration - it is simple aerodynamics connected to the air density =
decreasing with increasing altitude.=20
When considering the various reports of spinning on this forum how many =
actually take into consideration the altitude at which the exercise was =
undertaken.
Admittedly this does not explain the high?? accident rate but there is =
currently a lack of suitable training gliders in which to undertake spin =
training. The ASK21 has been designed as supposedly unspinnable - try it =
at 10,000 feet - you might be surprised. As said elsewhere how does the =
accident rate in the Puchacz compare to say the Bocian which was another =
excellent aircraft for spin recovery training. The DG505 is one of the =
newer German aircraft that also exhibits good characteristics for spin =
training although be aware of spinning close to the aft C of G.
I have to admit to deliberately spinnIng any aircraft (subject to its =
Cof A limitations) so that I am thoroughly aware of any peculiarites in =
respect of its handling. I would be amiss in not doing so as I would =
then be unable to thoroughly brief any pupils for their first flight in =
these aircraft. I also want to know what the characteristics of the =
aircraft are from a self preservation aspect - at least I will not be =
caught out by inadvertant departure from normal flight due to gusts, =
rotor, etc.

I haven't flown a puch, but I have been in a flat spin
in an SF34 with an instructor some years ago. The instructor
had decided to see how many turns we could manage in
a spin (note that after 3 you become a test pilot).
We were at 6500ft when we entered the spin. After 10
turns he decided to recover, but the spin was already
completely flat, with the nose gently nodding above
and below the horizon as we turned. Upon application
of the recovery control inputs, the spin continued
for another 3 turns (which gave plenty of time to start
worrying and thinking about the parachute) before we
eventually recovered. Unfortunately I never noted down
accurate start and finish heights in my log book, but
I think that we recovered at about 3500'. Needless
to say we never tried that again, and I wouldn't recommend
anyone prolonging a spin beyond 3 turns.

Jon Meyer wrote:

had decided to see how many turns we could manage in
a spin (note that after 3 you become a test pilot).

JAR requires 5 turns.


JAR 22.221

(b) The sailplane must be able to recover
from spins of at least five turns or such lesser
number at which the spin changes into a spiral
dive, by applying the controls in a manner
normal for recovery ...

etc.


Stefan

... and then you wonder why the back end fell off that
particular glider!


At 11:18 06 February 2004, Jon Meyer wrote:
I haven't flown a puch, but I have been in a flat spin
in an SF34 with an instructor some years ago. The instructor
had decided to see how many turns we could manage in
a spin (note that after 3 you become a test pilot).
We were at 6500ft when we entered the spin. After 10
turns he decided to recover, but the spin was already
completely flat, with the nose gently nodding above
and below the horizon as we turned. Upon application
of the recovery control inputs, the spin continued
for another 3 turns (which gave plenty of time to start
worrying and thinking about the parachute) before we
eventually recovered. Unfortunately I never noted down
accurate start and finish heights in my log book, but
I think that we recovered at about 3500'. Needless
to say we never tried that again, and I wouldn't recommend
anyone prolonging a spin beyond 3 turns.

At 14:48 06 February 2004, Jon Meyer wrote:
French engineering at its best!

That would be 'Scheibe' , makers of 'Le Moteur Falke'
?

:-)