Tow Plane Upsets......

Could you tell us about glider type, CG, weight and tow speed, especially
in
relation to manufacturer recommended tow speed?


At 14:01 30 April 2017, wrote:
I've seen this twice from the glider. The second time caught on a GoPro.

The failure mode appears to be recovering from slack in a nose up
condition=
..
The cause is a combination of physics, glider pilot training, and towing
in=
sporty conditions.

My first experience was at altitude behind a Pawnee. From the glider,
the
=
stick was full forward, little elevator authority, rope tight, and pilot
le=
aning forward. Glider nose was slowly lowering so the situation was
conver=
ging. Talking on the ground, the tow pilot never lost elevator authority
o=
r felt the need to release his end. The lesson learned was the wrong one
w=
ith little understanding. That this was strange, but safe and
recoverable
=
event.

The second experience was just after launch behind a CallAir. Similar
stor=
y from the glider, but a much different story from the tow end. Loss of
el=
evator authority, ground getting close, but situation improving. If I
had
=
had any clue that there was a problem at the other end of the rope, I
would=
have released, but from the first experience, I saw things as ok and
impro=
ving. Thankfully, it turned out ok, but with a much different lesson and
u=
nderstanding on the second try.

Having had some time to think about it. I think an understanding of
kiting=
should be required for anybody towing with a CG hook. Actually trying
to
=
train it at altitude is not a good idea because of loss of sight of the
tow=
plane. Remembering not to be nose up on slack recovery is. If you get
to=
this mode, just quickly release and go again.

I've since put a nose hook on my glider. This was a non-trivial
exercise,
=
but the opportunity presented itself and since I tow in sporty
conditions,
=
it seemed worth it. Given an understanding of the problem, this is kind
of=
belt and suspenders, so it probably should not be a requirement, but the
t=
raining is a must.