new tow plane/tow hitch

[jim]

We want to install a tow hitch on a recently acquired Husky in
preparation for the contest season. Is a Tost hitch required or
preferred for SSA sanctioned events? Is the venerable Schweitzer
hitch still OK ? If so, for how long? Tost is the standard in
Europe. Is the US moving toward that standard? Has anyone used the
Husky/Super Cub Tost hitch kit offered on Wings and Wheels?

[Brian[_1_]]

On Mar 14, 8:19*pm, jim > wrote:
> We want to install a tow hitch on a recently acquired Husky in
> preparation for the contest season.

*Is a Tost hitch required or> preferred for SSA sanctioned events?
Not required.
*Is the venerable Schweitzer> hitch still OK ? Yes
*If so, for how long? No end of life specified at this time?
*Tost is the standard in> Europe. *Is the US moving toward that
standard? Yes, but voluntarily due to the benifits of the tost hitch.
*Has anyone used the> Husky/Super Cub Tost hitch kit offered on Wings
and Wheels? I don't know anyone on RAS that has one, I believe the
Seattle Glider Council has Tost hitch's on their Super cub and
Pawnee's.

Brian

[Andy[_1_]]

On Mar 14, 7:19*pm, jim > wrote:
> We want to install a tow hitch on a recently acquired Husky in
> preparation for the contest season. *Is a Tost hitch required or
> preferred for SSA sanctioned events? *Is the venerable Schweitzer
> hitch still OK ? *If so, for how long? *Tost is the standard in
> Europe. *Is the US moving toward that standard? *Has anyone used the
> Husky/Super Cub Tost hitch kit offered on Wings and Wheels?

If you are going to be the one flying the Husky perhaps you should
make your decision based on whether you hope to be able to release the
rope in the event of an upset. My preference, if on the front end of
the rope, would be to have a Tost hook.

I don't know how many tow pilots we need to kill or maim before the
Schweizer hook is eliminated from tugs.

If you decide to go for the Schweizer hook you may want to consider
the inverted installation which some believe provides a better chance
of release.

Andy

[Bruce]

Andy wrote:
> On Mar 14, 7:19 pm, jim > wrote:
>> We want to install a tow hitch on a recently acquired Husky in
>> preparation for the contest season. Is a Tost hitch required or
>> preferred for SSA sanctioned events? Is the venerable Schweitzer
>> hitch still OK ? If so, for how long? Tost is the standard in
>> Europe. Is the US moving toward that standard? Has anyone used the
>> Husky/Super Cub Tost hitch kit offered on Wings and Wheels?
>
> If you are going to be the one flying the Husky perhaps you should
> make your decision based on whether you hope to be able to release the
> rope in the event of an upset. My preference, if on the front end of
> the rope, would be to have a Tost hook.
>
> I don't know how many tow pilots we need to kill or maim before the
> Schweizer hook is eliminated from tugs.
>
> If you decide to go for the Schweizer hook you may want to consider
> the inverted installation which some believe provides a better chance
> of release.
>
> Andy
We had a world class pilot write off an ASW20 in December. The schweizer
hook turned 180 degrees and sold him the rope at 50 feet... An anthill
saw to the rest.

Get a Tost...

--- news://freenews.netfront.net/ - complaints: ---

[lanebush]

There is a frustrating side to these discussions that seem to come up
every few months.

The schweizer hook works well enough to justify not removing a
serviceable one.
Tost has not applied for STC's in the US that would allow trouble free
approval.
I have heard that it is tough to get a Tost hook approved with a 337.

The above reasons have prevented a flood of Tost installations. It is
hard to spend $2,000 on a hook that may take a year to get approved if
your FSDO will even approve it at all. It really isn't just a matter
of negligence when someone continues using a schweizer hook but rather
the proverbial "between a rock and a hard place". Maybe Tost will
step up one day and apply for an STC. I hear that a new and improved
schweizer hook may be on the horizon.

XF

[Bruce Hoult]

On Mar 16, 4:57*am, Bruce > wrote:
> Andy wrote:
> > On Mar 14, 7:19 pm, jim > wrote:
> >> We want to install a tow hitch on a recently acquired Husky in
> >> preparation for the contest season. *Is a Tost hitch required or
> >> preferred for SSA sanctioned events? *Is the venerable Schweitzer
> >> hitch still OK ? *If so, for how long? *Tost is the standard in
> >> Europe. *Is the US moving toward that standard? *Has anyone used the
> >> Husky/Super Cub Tost hitch kit offered on Wings and Wheels?
>
> > If you are going to be the one flying the Husky perhaps you should
> > make your decision based on whether you hope to be able to release the
> > rope in the event of an upset. *My preference, if on the front end of
> > the rope, would be to have a Tost hook.
>
> > I don't know how many tow pilots we need to kill or maim before the
> > Schweizer hook is eliminated from tugs.
>
> > If you decide to go for the Schweizer hook you may want to consider
> > the inverted installation which some believe provides a better chance
> > of release.
>
> > Andy
>
> We had a world class pilot write off an ASW20 in December. The schweizer
> hook turned 180 degrees and sold him the rope at 50 feet... An anthill
> saw to the rest.

Seems strange. Unless the field is grossly too small you should have
multiple options from 50 ft and 60+ knots -- quite probably there is
still room to land straight ahead, a 90 degree turn and crosswind
landing is easy if you're still in the vicinity of the boundary fence
and the field is wide (or has a suitable other runway), and a 180 and
downwind landing should be well within the capabilities of a world
class pilot in a 20. We don't know the wind of course, but a headwind
strong enough to preclude landing downwind generally makes a lot more
space available straight ahead...

Perhaps you can explain the situation a bit more fully?

[BT[_3_]]

"
>>
>> We had a world class pilot write off an ASW20 in December. The schweizer
>> hook turned 180 degrees and sold him the rope at 50 feet... An anthill
>> saw to the rest.
>

How can a tow hook on the tow plane rotate (turn) 180 degrees, do you mean
it was mounted "inverted"?
And if mounted upright or inverted, the SGS hook, if properly installed and
maintained would not just, "sell him the rope".
Just because it was "inverted" means nothing.. they are all "inverted" when
installed on the glider.
Something was not maintained.

I noticed once between flights and I was out of the cockpit that the tow
plane end of the rope (hook) seemed to be almost "1/2" way to the release
point.
I reset it, did a tow and got out and looked again. It had moved again on
it's own. So now I start looking to see what would have happened to cause
that.
The release cable rides in a plastic casing inside the Pawnee, zip tied to
fuselage formers.

Some ties had aged and broke, the cable was free to sag. So bouncing in
turbulence on the way down, the cable bounced in the aft fuselage, no
"pressure" on the hook and it was pulling the release lever.

There is more to towing than inspecting the rope and the release system...
Check ALL of the airplane and it's parts.
The SGS hook failure is no different than if TOST springs were broken and
not caught on preflight inspection or checked during the day.
No different than a weak link failure.. No different than the engine
coughing and the tow purposefully releasing the rope.

Had a Stearman blow a jug, the glider pilot saw the puff of smoke and then
saw the rope release within a second of the puff.
Those are the chances you take... don't blame the hook, blame the preflight.

BT (Pawnee Tow Pilot on an SGS Upright Hook)

[Bruce]

Anecdotes make poor proof of thesis.

However - you are correct that the ultimate cause of the accident was
poor maintenance of the hook.
But - the failure mode is one the Tost/Ottfur does not have.
They cannot rotate in a horizontal plane around the mounting bolt.

If yours is welded on - good, if it is inverted - better. If not, as on
the Cessnas - your daily checks should include whether there is enough
friction to prevent rotation around the mount bolt.

If it does rotate it will back release. It is unlikely to do this at a
peaceful, stable moment in the tow.

One near miss - does someone have to die before we accept there is a risk?

This means there are at least two situations where the Schweizer hook is
unsafe. The other is failure to release under high lateral angle - which
can be overcome by inverted mounting. ref -
http://www.jdburch.com/Towstudy.htm

The Tost is safer - if you have the option I can't see why you would fit
an obsolete design that is no longer in production and is known to be
unsafe under circumstances that have killed a number of pilots - time to
move on.

Bruce

BT wrote:
> "
>>>
>>> We had a world class pilot write off an ASW20 in December. The schweizer
>>> hook turned 180 degrees and sold him the rope at 50 feet... An anthill
>>> saw to the rest.
>>
>
> How can a tow hook on the tow plane rotate (turn) 180 degrees, do you
> mean it was mounted "inverted"?
> And if mounted upright or inverted, the SGS hook, if properly installed
> and maintained would not just, "sell him the rope".
> Just because it was "inverted" means nothing.. they are all "inverted"
> when installed on the glider.
> Something was not maintained.
>
> I noticed once between flights and I was out of the cockpit that the tow
> plane end of the rope (hook) seemed to be almost "1/2" way to the
> release point.
> I reset it, did a tow and got out and looked again. It had moved again
> on it's own. So now I start looking to see what would have happened to
> cause that.
> The release cable rides in a plastic casing inside the Pawnee, zip tied
> to fuselage formers.
>
> Some ties had aged and broke, the cable was free to sag. So bouncing in
> turbulence on the way down, the cable bounced in the aft fuselage, no
> "pressure" on the hook and it was pulling the release lever.
>
> There is more to towing than inspecting the rope and the release
> system... Check ALL of the airplane and it's parts.
> The SGS hook failure is no different than if TOST springs were broken
> and not caught on preflight inspection or checked during the day.
> No different than a weak link failure.. No different than the engine
> coughing and the tow purposefully releasing the rope.
>
> Had a Stearman blow a jug, the glider pilot saw the puff of smoke and
> then saw the rope release within a second of the puff.
> Those are the chances you take... don't blame the hook, blame the
> preflight.
>
> BT (Pawnee Tow Pilot on an SGS Upright Hook)

--- news://freenews.netfront.net/ - complaints: ---

[Tony[_5_]]

On Mar 16, 4:09*am, Bruce > wrote:
> Anecdotes make poor proof of thesis.
>
> However - you are correct that the ultimate cause of the accident was
> poor maintenance of the hook.
> But - the failure mode is one the Tost/Ottfur does not have.
> They cannot rotate in a horizontal plane around the mounting bolt.
>
> If yours is welded on - good, if it is inverted - better. If not, as on
> the Cessnas - your daily checks should include whether there is enough
> friction to prevent rotation around the mount bolt.
>
> If it does rotate it will back release. It is unlikely to do this at a
> peaceful, stable moment in the tow.


I've never heard of this happening, until now. Can you elaborate. Was
the towhook rotated around backwards before the tow started?

[BT[_3_]]

We are welded... but not inverted..
A strong pull to the side will not allow an SGS hook to intentionally
release, but yes a TOST can release under any directional pull.
I say intentional release, not inadvertant release.

BT

"Bruce" > wrote in message
...
> Anecdotes make poor proof of thesis.
>
> However - you are correct that the ultimate cause of the accident was poor
> maintenance of the hook.
> But - the failure mode is one the Tost/Ottfur does not have.
> They cannot rotate in a horizontal plane around the mounting bolt.
>
> If yours is welded on - good, if it is inverted - better. If not, as on
> the Cessnas - your daily checks should include whether there is enough
> friction to prevent rotation around the mount bolt.
>
> If it does rotate it will back release. It is unlikely to do this at a
> peaceful, stable moment in the tow.
>
> One near miss - does someone have to die before we accept there is a risk?
>
> This means there are at least two situations where the Schweizer hook is
> unsafe. The other is failure to release under high lateral angle - which
> can be overcome by inverted mounting. ref -
> http://www.jdburch.com/Towstudy.htm
>
> The Tost is safer - if you have the option I can't see why you would fit
> an obsolete design that is no longer in production and is known to be
> unsafe under circumstances that have killed a number of pilots - time to
> move on.
>
> Bruce
>
> BT wrote:
>> "
>>>>
>>>> We had a world class pilot write off an ASW20 in December. The
>>>> schweizer
>>>> hook turned 180 degrees and sold him the rope at 50 feet... An anthill
>>>> saw to the rest.
>>>
>>
>> How can a tow hook on the tow plane rotate (turn) 180 degrees, do you
>> mean it was mounted "inverted"?
>> And if mounted upright or inverted, the SGS hook, if properly installed
>> and maintained would not just, "sell him the rope".
>> Just because it was "inverted" means nothing.. they are all "inverted"
>> when installed on the glider.
>> Something was not maintained.
>>
>> I noticed once between flights and I was out of the cockpit that the tow
>> plane end of the rope (hook) seemed to be almost "1/2" way to the release
>> point.
>> I reset it, did a tow and got out and looked again. It had moved again on
>> it's own. So now I start looking to see what would have happened to cause
>> that.
>> The release cable rides in a plastic casing inside the Pawnee, zip tied
>> to fuselage formers.
>>
>> Some ties had aged and broke, the cable was free to sag. So bouncing in
>> turbulence on the way down, the cable bounced in the aft fuselage, no
>> "pressure" on the hook and it was pulling the release lever.
>>
>> There is more to towing than inspecting the rope and the release
>> system... Check ALL of the airplane and it's parts.
>> The SGS hook failure is no different than if TOST springs were broken and
>> not caught on preflight inspection or checked during the day.
>> No different than a weak link failure.. No different than the engine
>> coughing and the tow purposefully releasing the rope.
>>
>> Had a Stearman blow a jug, the glider pilot saw the puff of smoke and
>> then saw the rope release within a second of the puff.
>> Those are the chances you take... don't blame the hook, blame the
>> preflight.
>>
>> BT (Pawnee Tow Pilot on an SGS Upright Hook)
>
> --- news://freenews.netfront.net/ - complaints: ---