The SSA was kind enough to mail me nice copies of STC's issued to Javelin
Aircraft Company for tow hook installation on Cessna 180, 185 & 321
Aircraft (STC SA271CE) and for Cessna 120, 140, 170 & 305 Aircraft (STC
SA268CE). The STC's include many variants of the models listed. Both STC's
reference Cessna Report No. S-000-134 (Page iii) Revision B dated 5/3/62
- which is probably the Cessna Engineering Analysis.

Gasser Banner says they have not manufactured brackets and hooks for the
Cessna 180 under their STC for many, many years but will sell the
documents needed for fabrication for $75 - which is a modest cost
considering the hassle. I may purchase just to see how it compares with
the Javelin method.

I have gotten lots of e-mail recommending using a TOST hook or inverted
installation of the Schweizer hook. I have e-mailed TOST hoping to get
information on their E85 release - mainly so I can figure out how to mount
it on the 180 tailwheel (not a leaf spring) and rig a release. I am still
assembling material for review by my A&P/IA so I don't buy anything I
won't actually be able to get approved. None of the experts liked the idea
of pulling the rope for release and pointed out that the FAA Advisory
Circular recommends a lever with a 5:1 mechanical advantage.

Rod's link below shows 337-approved inverted installation of Schweizer
hook on a Pawnee leaf spring tailwheel.

Thanks for all the comments. I will post what I find out from TOST.

Stuart

Rod Pool wrote:

Stuart

Before useing a Schweizer tow rig give serious consideration to the
info on this website

http://home.att.net/~jdburch/index.htm

I too would reccommend a tost tow rig only. Far safer for both the tow
pilot and glider.

NTSB stats show on average one tow pilot death each year- upsets on
tow with no chance of recovery.

I think the FAA data is way out of date and should have been revisited
long ago.
Good luck
Rod