ASW 20 SPIN CHARACTERISTICS

On the 20, everything is flush in the full negative position.

--
Bert Willing

ASW20 "TW"


"JJ Sinclair" a écrit dans le message de
...
I believe the LS-6 does it that way (flaps and ailerons all even in full
negative flap position) my recollection of the 20 is that everything is
even at
zero flap and zero stick. One can set it up as one wishes, but one may be
dialing in undesired consequences.
I remember the Boeing engineer who told me, "Aircraft are designed by
geniuses
to be operated by idiots".
JJ Sinclair

There was some discussion about ten years ago that a contributing
factor in the early '20 accidents might have been the type of sealing
tape used on the flaps and ailerons. Specifically, before the
wholesale adoption of Mylar seals, many of the older ships had white
cloth tape on the lower surface that could bulge out at the hinge line
under certain airflow conditions, presumably triggering some sort of
undesirable behavior.

Anyone recall this or know if it was true?

Chip Bearden

(Chip Bearden) wrote in message . com...
There was some discussion about ten years ago that a contributing
factor in the early '20 accidents might have been the type of sealing
tape used on the flaps and ailerons. Specifically, before the
wholesale adoption of Mylar seals, many of the older ships had white
cloth tape on the lower surface that could bulge out at the hinge line
under certain airflow conditions, presumably triggering some sort of
undesirable behavior.

Anyone recall this or know if it was true?

Chip Bearden

Reply: Quite true. '20 is very sensitive to the quality of sealing on
both top and bottom of the wing. Remakable affect on both performance
and handling.
UH

(Chip Bearden) wrote in message
.com...
. Specifically, before the wholesale adoption of Mylar seals, many of the
older ships had white cloth tape on the lower surface that could bulge out at
the hinge line under certain airflow conditions, presumably triggering some
sort of undesirable behavior.


Worse yet is that this cloth tape will shrink over time and can restrict
control surface travel. If you have not replaced your cloth tape in several
years you could have less travel than you should. You can of course pull or
push real hard to get to the stop but that is not a good thing to have to do.

Robert Mudd

It's true that many ASW20A's were/are sealed with cloth tape on the
underside of the flaps and sometimes the ailerons. It is needed for
the flaps because of the 55 degree (jesus)down flap setting for short
field landings. Mylar would just peel off when trying this flap
psoition during your control checks.

Mine is sealed with cloth tape and I intend to leave it on the
underside of the flaps. I have looked at how it is installed. It would
appear it was put on with full negative flap applied and even then a
small amount of "slack" has been left and pushed up into the gap by a
small amount. No matter what flap setting I use this "slack" always
stays up in the gap.

I would think it unlikely that cloth tape contributed to spinning
accidents. More likely poor energy management and/or the use of
landing flap before speed has been set and final turn complete.

Always complete your final turn, check your speed, make sure you are
going to make the field, check your speed, then select whichever
landing flap position you want, check your speed and use further
airbrake if required, continue checking you speed. Sorry if this seems
like teaching Granny to suck eggs.

Andy Henderson
ASW20FP


(Chip Bearden) wrote in message . com...
There was some discussion about ten years ago that a contributing
factor in the early '20 accidents might have been the type of sealing
tape used on the flaps and ailerons. Specifically, before the
wholesale adoption of Mylar seals, many of the older ships had white
cloth tape on the lower surface that could bulge out at the hinge line
under certain airflow conditions, presumably triggering some sort of
undesirable behavior.

Anyone recall this or know if it was true?

Chip Bearden

Andy Henderson wrote:

It's true that many ASW20A's were/are sealed with cloth tape on the
underside of the flaps and sometimes the ailerons. It is needed for
the flaps because of the 55 degree (jesus)down flap setting for short
field landings. Mylar would just peel off when trying this flap
psoition during your control checks.

*Only* 55 degrees? We do 90 degrees in HP-Land. I use wide Scotch plastic
tape applied to the outside surface to seal. Yes, using mylar may be
feasible but it is very difficult to keep stuck in place on these ships.

Regards,

-Doug


Mine is sealed with cloth tape and I intend to leave it on the
underside of the flaps. I have looked at how it is installed. It would
appear it was put on with full negative flap applied and even then a
small amount of "slack" has been left and pushed up into the gap by a
small amount. No matter what flap setting I use this "slack" always
stays up in the gap.

Yup. Same here.

Good post Andy,
When the 20 first came out we had a rash of accidents, like 20 or more
world-wide. Then things settled down and the carnage stopped. Why? I have an
opinion, lots of guys climbed out of the 301 libelle and bought the hot new
toy. Think about the differences; The 301 had automatic elevator hook-up, the
20 didn't. Hence, a bunch of us forgot to hook things up. The 301 flaps only
went down about 15 degrees, the 20 flaps went way down. Hence a bunch of
landing accidents. On the 301, the stick only moved the ailerons, whereas in
the 20, everything out there moved and therefore a bit of heavy-handed input
could get one in trouble a whole lot faster. The 301 was nimble and quick, try
to be nimble and quick in your 20, with the flaps down, and one could end up
with rocks in the cockpit.
Why didn't we just stick with the good old 301 libelle?
JJ Sinclair