On Sunday, April 30, 2017 at 6:00:26 PM UTC-4, Dan Marotta wrote:
Following up on the tow release levers in the three tugs at Moriarty:

Pawnee - lever is 2 1/2 feet long, hinged below the floor. Has a throw
of about 2 feet.
CallAir - Very similar to the Pawnee.
Ag Wagon - Lever is only about 8 inches long, mounted near the throttle,
and is pushed (rather than pulled) to actuate. I'm not too sure that
one would be of much use when the Schweizer hook is under high load.

Dan

On 4/30/2017 1:24 PM, George Haeh wrote:
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.





--
Dan, 5J

The handle on the Pawnee that you make reference to was the original dump handle for the gate on the hopper. It is located on the left side extending up from below the surface of the floor. The assembly has two attach points that hold it in place. This assembly makes a great release mechanism for the release handle. Just yesterday I finished the assembly of my Tost Tow Hook on my Pawnee, I used this handle as the release handle, the location of this handle along with the length of the arm provides the best option for a release assembly. I also plan on adding a spring on the arm that will act as a positive pressure upon being in the closed position.