ASW-20 spins

I was much more lucky in my ASW-27 at 70% CG when I had a windshear induced
stall while moving to flap L at ~300 above threshold. I lost 269' and was
fortunate to recover over lower ground before having to dodge a topsoil
pile in the neighboring gravel pit.

With headwind component = TAS - GS, the flight data shows 3 windshears,
each over a 2 second interval, of -17, +23, -28 kt (application of
Pythagorean sum of squares of a triangle on the final shear yields 6 kt of
apparent headwind giving -34 kt -- TWICE the recorded wind).

Recovery action was flaps negative and stick forward.

The usual stall practice at 3000 AGL with a 1 kt/second deceleration has
little resemblance to a low level windshear stall.

More details on:

https://www.dropbox.com/sh/lq9osn15b...wuYvScXya?dl=0

I watched one of those early ASW 20 fatal spins. It was from slow
straight
=
and level flight, not thermaling. The wing dropped sharply and the glider
e=
ntered a conventional, nose-down spin. The recovery began almost
immediatel=
y (approx. 1/4 turn) but unfortunately there was not sufficient altitude
(t=
his began at approx. 300 ft AGL) and the pilot was killed when the glider
i=
mpacted the ground slightly nose down (i.e., the recovery was almost
comple=
te) but still sinking. Undocumented tail ballast was probably a factor,
as
=
with UH's situation. Pilot incapacitation due to dehydration may also
have
=
been a factor. The final blow, so to speak, was the lack of a headrest in
t=
his very early '20 and a battery pack behind the head that came loose.
The
=
pilot was an experienced, high-time competition pilot and instructor. All
o=
f the contributing factors were avoidable.

Chip Bearden
ASW 24 "JB"
U.S.A.

I'm very glad this worked out.

But I have my doubts about the wisdom of using negative flaps for stall recovery, especially close to the ground. I don't think that this can be said to be a good practice in general and I would recommend heartily against in my own ASW-20B.

-Evan Ludeman / T8



On Wednesday, June 3, 2015 at 11:15:05 PM UTC-4, George Haeh wrote:
I was much more lucky in my ASW-27 at 70% CG when I had a windshear induced
stall while moving to flap L at ~300 above threshold. I lost 269' and was
fortunate to recover over lower ground before having to dodge a topsoil
pile in the neighboring gravel pit.

With headwind component = TAS - GS, the flight data shows 3 windshears,
each over a 2 second interval, of -17, +23, -28 kt (application of
Pythagorean sum of squares of a triangle on the final shear yields 6 kt of
apparent headwind giving -34 kt -- TWICE the recorded wind).

Recovery action was flaps negative and stick forward.

The usual stall practice at 3000 AGL with a 1 kt/second deceleration has
little resemblance to a low level windshear stall.

More details on:

https://www.dropbox.com/sh/lq9osn15b...wuYvScXya?dl=0

I watched one of those early ASW 20 fatal spins. It was from slow
straight
=
and level flight, not thermaling. The wing dropped sharply and the glider
e=
ntered a conventional, nose-down spin. The recovery began almost
immediatel=
y (approx. 1/4 turn) but unfortunately there was not sufficient altitude
(t=
his began at approx. 300 ft AGL) and the pilot was killed when the glider
i=
mpacted the ground slightly nose down (i.e., the recovery was almost
comple=
te) but still sinking. Undocumented tail ballast was probably a factor,
as
=
with UH's situation. Pilot incapacitation due to dehydration may also
have
=
been a factor. The final blow, so to speak, was the lack of a headrest in
t=
his very early '20 and a battery pack behind the head that came loose.
The
=
pilot was an experienced, high-time competition pilot and instructor. All
o=
f the contributing factors were avoidable.

Chip Bearden
ASW 24 "JB"
U.S.A.

Didn't have the time to check exactly where the the flap handle was going.



At 12:00 04 June 2015, Tango Eight wrote:
I'm very glad this worked out.

But I have my doubts about the wisdom of using negative flaps for stall
recovery, especially close to the ground. I don't think that this can be
said to be a good practice in general and I would recommend heartily
against in my own ASW-20B.

-Evan Ludeman / T8



On Wednesday, June 3, 2015 at 11:15:05 PM UTC-4, George Haeh wrote:
I was much more lucky in my ASW-27 at 70% CG when I had a windshear
induced
stall while moving to flap L at ~300 above threshold. I lost 269' and
was
fortunate to recover over lower ground before having to dodge a topsoil
pile in the neighboring gravel pit.

With headwind component = TAS - GS, the flight data shows 3 windshears,
each over a 2 second interval, of -17, +23, -28 kt (application of
Pythagorean sum of squares of a triangle on the final shear yields 6 kt
of
apparent headwind giving -34 kt -- TWICE the recorded wind).

Recovery action was flaps negative and stick forward.

The usual stall practice at 3000 AGL with a 1 kt/second deceleration
has
little resemblance to a low level windshear stall.

More details on:


https://www.dropbox.com/sh/lq9osn15b...wuYvScXya?dl=0

I watched one of those early ASW 20 fatal spins. It was from slow
straight
=
and level flight, not thermaling. The wing dropped sharply and the
glider
e=
ntered a conventional, nose-down spin. The recovery began almost
immediatel=
y (approx. 1/4 turn) but unfortunately there was not sufficient
altitude
(t=
his began at approx. 300 ft AGL) and the pilot was killed when the
glider
i=
mpacted the ground slightly nose down (i.e., the recovery was almost
comple=
te) but still sinking. Undocumented tail ballast was probably a
factor,
as
=
with UH's situation. Pilot incapacitation due to dehydration may also
have
=
been a factor. The final blow, so to speak, was the lack of a headrest
in
t=
his very early '20 and a battery pack behind the head that came loose.
The
=
pilot was an experienced, high-time competition pilot and instructor.
All
o=
f the contributing factors were avoidable.

Chip Bearden
ASW 24 "JB"
U.S.A.

So far, I've been intentionnaly spinning almost all flapped gliders I flew (about two dozends), and putting flaps to full negative *always* helps to end the spin earlier. Especially close to the ground this is very important, as every fractions of a second counts. Many years ago, when I did an unintenional spin for stupid reasons close to the ground, the negative flaps saved my live.


At 12:00 04 June 2015, Tango Eight wrote:
I'm very glad this worked out.

But I have my doubts about the wisdom of using negative flaps for stall
recovery, especially close to the ground. I don't think that this can be
said to be a good practice in general and I would recommend heartily
against in my own ASW-20B.

-Evan Ludeman / T8