Pawnee Tow Hook STC

I know nothing at all about the regulations, paperwork etc. required for
fitting tow hooks in the USA. However, if you fit a Schweizer hook PLEASE
make sure that it is modified to make it easier to release under load.
Remember that it is a banner towing hook, and no-one gets killed if you
can't release the banner!

There is a modification to the Schweizer hook in the U.K., this was done
after we killed a few tug pilots.

The modification to Schweizer type banner towing hooks is approved and
highly recommended by the BGA.

It may be found at:
British Gliding Association.
http://www.gliding.co.uk/
Go to: Info for Clubs & Members.
http://www.gliding.co.uk/bgainfo/news.htm
Go to: Technical.
http://www.gliding.co.uk/bgainfo/technical/news.htm
Go to: Airworthiness Directives.
http://www.gliding.co.uk/bgainfo/technical/ads.htm
Go to: Motor Glider and Tug issues.
http://www.gliding.co.uk/bgainfo/tec...iderandtug.pdf
See: Page 2 - item 14. Schweitzer type banner towing hooks.

You will not be able to view the mod. on-line, or download it; but I am sure
they will mail it to you (let me know if you have problems).

The release wire is attached to a double flat bar which pivots on a bolt at
the bottom through the fixed part of the hook. Half way along the bar is a
round stud which has to slide forward on the upward releasing fitting in
order to release. It is high friction between this stud and the releasing
fitting which causes the problem (high release loads when the towrope is
under high tension). The fix is to put in a roller bearing instead of the
round stud, so that it rolls off the releasing fitting instead of sliding.

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


"Shawn Curry" wrote in message
link.net...

Greetings,

Does anybody have any information about Tost or Schweizer tow hook STCs
for a Pawnee? Our A&P hasn't found any info. Does it require a field
approval or is their an STC out there?

Thanks,
Shawn

"W.J. \(Bill\) Dean \(U.K.\)." wrote in message ...

There is a modification to the Schweizer hook in the U.K., this was done
after we killed a few tug pilots.

There is also a modification to the Schweizer hook (actually, a mod to
the mount) that is approved in the US, it consists of turning the
release assembly upside down, so that any upward load is taken against
the fixed part of the release and not the hinged arm. This prevents an
excessive upward load from jamming the release. Contact Turf Soaring
at http://www.turfsoaring.com/ for more info on this mod (it was
apparently invented by one of Turf's tow pilots).

All of Turf's Pawnees have this mod installed.

Kirk

"W.J. \(Bill\) Dean \(U.K.\)." wrote in message ...
I know nothing at all about the regulations, paperwork etc. required for
fitting tow hooks in the USA. However, if you fit a Schweizer hook PLEASE
make sure that it is modified to make it easier to release under load.
Remember that it is a banner towing hook, and no-one gets killed if you
can't release the banner!

There is a modification to the Schweizer hook in the U.K., this was done
after we killed a few tug pilots.

The modification to Schweizer type banner towing hooks is approved and
highly recommended by the BGA.

It may be found at:
British Gliding Association.
http://www.gliding.co.uk/
Go to: Info for Clubs & Members.
http://www.gliding.co.uk/bgainfo/news.htm
Go to: Technical.
http://www.gliding.co.uk/bgainfo/technical/news.htm
Go to: Airworthiness Directives.
http://www.gliding.co.uk/bgainfo/technical/ads.htm
Go to: Motor Glider and Tug issues.
http://www.gliding.co.uk/bgainfo/tec...iderandtug.pdf
See: Page 2 - item 14. Schweitzer type banner towing hooks.

You will not be able to view the mod. on-line, or download it; but I am sure
they will mail it to you (let me know if you have problems).

The release wire is attached to a double flat bar which pivots on a bolt at
the bottom through the fixed part of the hook. Half way along the bar is a
round stud which has to slide forward on the upward releasing fitting in
order to release. It is high friction between this stud and the releasing
fitting which causes the problem (high release loads when the towrope is
under high tension). The fix is to put in a roller bearing instead of the
round stud, so that it rolls off the releasing fitting instead of sliding.

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


"Shawn Curry" wrote in message
link.net...

Greetings,

Does anybody have any information about Tost or Schweizer tow hook STCs
for a Pawnee? Our A&P hasn't found any info. Does it require a field
approval or is their an STC out there?

Thanks,
Shawn

Phila. Glider has installed Tost on Pawnee, contact me for details