CG hook on aero tows??

So does any one have an actual list of tug upset accidents with
towplane type, glider type and circumstances?
Just off hand I can't remember any in Australia and yes even when you
use low tow the upset possibility exists after liftoff and before
transition to low tow.
We've had plenty of towplane/glider midairs which makes existence as
a tow pilot 10 times as likely to kill you as cropdusting per hour.

Mike Borgelt

Ian Strachan wrote in message ...
In article , Andy
Durbin writes

snip

LBA certification
prohibits the use of CG hook for aerotow

Does not that tell you something, then?

1. With over 1500 hours in the ASW 19 I am very familiar with aero tow
with CG hooks.

So I have no doubt also thought the glider pilots who got out of
position and killed the tug pilot.


If you have data on those accidents I would be interested in seeing
it. I used to be a tug pilot (2 USA clubs and 1 UK club). The only
tug pilot fatalities I am familiar with that resulted from glider
being too high did not involve a cg hook.


Just do not come to my club and expect to tow on your aft hook, or
anywhere where I am towing. I would have thought where life-and-death
was concerned you could be a tad more humble about your undoubted
handling abilities. But perhaps unlike the rest of us, you never have
an off-day ......

One of the reasons I included the forward hook in my order was the
slim chance that I would return to UK.


What should I do with my ASW 19? I had planned to transition my low
time wife to it but perhaps the risks are just too great. Is there an
approved forward hook modification?


Andy (GY)

Eric Greenwell wrote in message ...

I found the forward hook (about 1 to 2
feet back from the nose) was better in a crosswind, better if the wing
runner was clumsy, better if I got distracted on tow, better in rough
air, and I never ran over the tow rope, which happened once in a while
with the CG hook.

Thanks for that feedback. I'll try it next tow.

When you say it was better in those respects are you comparing your 26
on forward hook to your 26 on cg hook or with your 20 on cg hook.


Andy (GY)

Eric Greenwell wrote in message ...

I also had 1000+ hours on my ASW 20 CG hook (and another 600 on other
gliders) when I had a forward hook installed.


Sorry, I read this too quickly before I posted the first reply. I now
realize that you modified your 20 and were not comparing with the 26.
Perhaps you could send me more info on the mod. I may want to do it
to my 19.


thanks


Andy (GY)

Andy Durbin wrote:
Eric Greenwell wrote in message ...

I also had 1000+ hours on my ASW 20 CG hook (and another 600 on other
gliders) when I had a forward hook installed.

Sorry, I read this too quickly before I posted the first reply. I now
realize that you modified your 20 and were not comparing with the 26.
Perhaps you could send me more info on the mod. I may want to do it
to my 19.

When countries began requiring forward hooks for aero tow about 15 years
ago, Schleicher came out with retrofits for their gliders. I got the
pieces and instructions for doing this on my 20 from the Schleicher
dealer and had it installed. I assume the same is available for the 19.

--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

There have been several fatal "aerotow upset" accidents in the U.K. where
it seems certain that towing on a hook intended for winch launching was a
factor.

These include:
Lasham new year 1963/4 Auster towing a Ka 6cr or Skylark 2 (I forget which),
Tug at Aboyne towing a Ka 6e,
Tugs (Super Cubs) towing K 18s at Portmoak and Dunstable (within a few
months of each other), this led to the tests by Chris Rollings, Verdun Luck
and Brian Spreckley at Booker see
http://www.glidingmagazine.com/ListF...Dtl.asp?id=327 .

Will that do, or how many others do you need?

Any glider which launches well on a cable using the aft launching hook, will
do the same behind a tug maybe killing the tug pilot in the process. If
you really think that the glider pilot can control or stop this process once
it starts, READ THE ARTICLE LINKED ABOVE; I suggest that the pilots who
conducted those tests were more experienced, more current and just plain
better than you.

To my certain knowledge it is possible to fit a forward hook for aerotow to
the ASW 15, 17, ASK 18, ASW 19, 20, and 22 and the Pegase; the ASK 21 and 23
and I think later types were fitted with it as standard. I don't know of
any examples of these in club (as distinct from private owner) use which
have not been modified.

I think you would be very wise to have your ASW 19 fitted with the approved
forward hook modification before your wife flies it on aerotow.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.


"Andy Durbin" wrote in message
om...


Ian Strachan wrote in message
...


In article , Andy
Durbin writes

snip

LBA certification
prohibits the use of CG hook for aerotow


Does not that tell you something, then?


1. With over 1500 hours in the ASW 19 I am very familiar with aero tow
with CG hooks.


So I have no doubt also thought the glider pilots who got out of
position and killed the tug pilot.


If you have data on those accidents I would be interested in seeing
it. I used to be a tug pilot (2 USA clubs and 1 UK club). The only
tug pilot fatalities I am familiar with that resulted from glider
being too high did not involve a cg hook.


Just do not come to my club and expect to tow on your aft hook, or
anywhere where I am towing. I would have thought where life-and-death
was concerned you could be a tad more humble about your undoubted
handling abilities. But perhaps unlike the rest of us, you never have
an off-day ......


One of the reasons I included the forward hook in my order was the
slim chance that I would return to UK.

What should I do with my ASW 19? I had planned to transition my low
time wife to it but perhaps the risks are just too great. Is there an
approved forward hook modification?

Andy (GY)

In article , Andy
Durbin writes

I have flown the last 15 or so years with aerotow on a cg hook. My new
ASW-28 has forward and CG hooks but I have never used the forward
hook.

First of all, if the manual says to not use the C.G. hook
for aerotow, I personally wouldn't try it, even once.
But that's just me.

Next, as a tow pilot, if I ever towed someone and found out
they used a CG hook not allowed by POH, I'd
have a lengthy discussion with the pilot. I'd explain why
I'm not interested in doing abnormal procedures without
being informed before the flight. I don't believe
I always must do everything recommended, but if I
decide not to, I MUST acknowledge that I am now a
test pilot, and have perhaps voided any insurance. I also
need to get the approval of anyone else put at greater risk
(a second pilot, the tug driver, etc.).

We had this happen when flying the Blanik L-13 without the
canopy. There was quite a bit of discussion and agreement
from all parties before doing this. In the end everything
worked out fine, but more importantly, everyone had input
and was comfortable that precautions and research had been
done. And boy was it FUN!

I would think glider CG might be an issue here.
In the past 15 years, you've flown using the CG hook of
a glider that has a certain CG and a certain, perhaps
fairly forward, loading. A new glider with a different
placement of the CG hook relative to the CG may
be a completely different ride. If you do try it, keep
meticulous records, and send a report to the manufacturer.
I bet they'd like to know, since maybe their test pilot
was too chicken to do it himself.

If you do decide to use the CG hook for an aerotow,
despite the voices here and the POH, at the very least
get the cooperation of the tow pilot, since it isn't just
you taking a risk. And if you can't find a towpilot to
agree, maybe that's a sign...

Another thought...is it possible to rig a towline in such a way
that it has TWO rings? So that one could release the nose
ring and then be on the belly ring? Could one then
launch (the super dangerous part) using the nose ring and
then release this and experiment using the belly ring up at
high altitude?

Hmmm...I guess not since they both release using the same
mechanism...but otherwise this seems to be a better way
to experiment than taking off on the CG hook.
I'd suspect that a factory test pilot who wanted to test both
hooks for aerotow might try something like this...with
two individual release knobs perhaps...

Of course all of this begs the question: if the glider
HAS a nose hook for aerotow, why not just use it?
But that certainly wouldn't encourage a nice armchair
discussion, right?

On 6 Jan 2004 05:38:04 -0800, (Andy Durbin)
wrote:

What should I do with my ASW 19? I had planned to transition my low
time wife to it but perhaps the risks are just too great. Is there an
approved forward hook modification?

The only ones I've looked at in the UK (closely enough to count tow
hooks that is) have been fitted with both, so I'd always assumed that
was the norm.

Could there be a difference in factory spec between deliveries within
Europe and those to the US? That could make sense given the prevalence
of winching in Europe and its rarity on the US.


--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

Some branches of this thread are starting to hot up. I call Godwin in four!

Bob K.

Bob Kuykendall wrote:
Some branches of this thread are starting to hot up. I call Godwin in four!

Bob K.
Yeah sure you would say that. What are you some kind of Naz....
He He Just kinding :-)