On 9/12/2012 2:06 AM, BruceGreeff wrote:
Hi Eric

Sorry to be obscure - I think we actually agree entirely. Follow the
standard procedure until the spin stops.

I am sure you are way more experienced than I. So - free opinion and
worth every cent you paid.

Aviate first comment applies to thinking all the time - rather than
applying rote process.

In my experience - It helps to always try to have the objective in
mind when you do something in the cockpit. In a departure from
controlled flight, that is turning into "something" the first thing
to do is to correct the condition that caused the departure. In the
instances we were discussing that is a stalled wing. If your primary
objective is to un-stall the wing then, again in my limited
experience, the manual on a flapped ship says something along the
lines of "reduce the flap setting".

So my thinking is first move flaps to neutral or negative as
indicated. This will reduce AoA, and MAY arrest the departure.

Then one should assess what the aircraft is actually doing.

If and only if you are simultaneously rotating about all three axes
with relatively stable speed and the G force is not increasing and
the other indicators unique to the type of aircraft you are flying
indicate that you are in fact spinning - then the logical thing to do
is to initiate the standard spin recovery.

If you are in a steeply descending turn with airspeed increasing and
experiencing elevated G load, you are probably in a spiral dive.

If you are - like Bruno - simply in a bit of a slip, with one wing
low and airspeed and control normal, well straighten up and fly
right.

In the vast majority of gliders the reduction in AoA from flap change
will arrest the departure. The aircraft may be at an unusual
attitude, but it is fully under control. (as was the case in the
video)

Following a rote spin recovery in this situation is irrational , and
with a flapped ship it may be especially dangerous. Many gliders
will accelerate rapidly enough that - especially if you have not
reduced the flap setting - you will exceed limiting speed for the
aircraft configuration and damage something. In at least two cases I
have seen this was at least a contributory factor in a fatality.

Therefore I advocate - first reduce AoA, by changing flap - that way
you have taken the action most likely to recover with the minimum
disturbance and very importantly, you have configured your aircraft
for the possible / probable high speed that will eventuate if you do
have to recover from a fully developed spin or spiral dive. And then
continue with the rest of the standard recovery process until the
spin is arrested.

Again I think we agree - the critical point for me is that in a
flapped aircraft the flaps should be the first control input, and
that the result of each input should be assessed lest you do
something inappropriate to the circumstances simply because it is the
next action on the standard recovery procedure.

It's my understanding from my flight manual that the flap reduction and
the standard spin recovery motions are to be applied simultaneously.
Applying the flap reduction first can work (at least, under some
circumstances), but it is not what is specified in the manual, and I
have had no problems by doing the two things simultaneously. Why wait to
see if the flap reduction fails? That will only increase the height lost
and allow the glider to go further into the spin.

As a thought - consider what might have happened with Bruno if he had
immediately centralised the controls without changing flap first.

I have not watched the video, but the standard spin recovery does not
include centralizing the controls (the ailerons - yes, the stick and
rudder - no). Had Bruno done standard spin recovery, my belief is the
glider would have recovered immediately, and he could have continued
thermalling with very little height loss or disruption.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)