Tow Hook on Cessna 180 - Update
Stuart Grant
for a legal installation yet but I am now relatively certain it is
possible. Neal Pfeiffer was kind enough to put me in touch with
Charles Pate at Cessna's Structural Engineering Department. Charles
directed me to the FAA's Advisory Circular 43.13-2A figure 8.9 which
is online at:
http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular
.nsf/1ab39b4ed563b08985256a35006d56af/e533bb05389c90e486256a54006e47b2/$FILE
/Chapter%201-8.pdf
If it wraps cut and paste it as required to make a link. It gives
general guidelines for installing tow hooks on tailwheel and tricyle
gear airplanes.
He also forwarded a document file which described Cessna's testing of
100 series aircraft for towing and how nearly all structurally handle
1,200 lbs x 150% at various tow angles. This document is probably
available on letterhead from Cessna's Structural Department. Allow at
least a couple of weeks if you need a copy. Mr. Pate also sent photos
of an installation he saw in Texas.
The best information he sent were some unofficial copies of the
Javelin Aircraft STC for the tow-hook installation. He said that David
Blanton Sr. who passed away a few years ago donated the tow-hook STC
to the SSA. The STC drawing shows how to fabricate a steel bracket
that connects to the tailwheel using longer versions of the original
through-bolts. It is a very clean installation. I have been told
Gasser Banner can supply the bracket and the Schweizer hook. I have
contacted the SSA about purchasing the STC and Gasser Banner about
getting the Bracket and Hook. Interesting that the Javelin STC uses a
nylon cord running from the hook along the outside of the fuselage
through the pilot side window tied to the "assist strap" with a
specified amount of slack. To release the tow line you pull on the
cord. Seems like a very elegant solution - especially if you only plan
on towing ocassionally.
I hope the SSA has its act together enough to market the STC.
Hope this will be helpful to someone else in the future.
Vaughn
"Stuart Grant" <smg...@bellsouth.net> wrote in message
news:121d239b.03100...@posting.google.com...
> Charles Pate at Cessna's Structural Engineering Department. Charles
> directed me to the FAA's Advisory Circular 43.13-2A figure 8.9 which
> is online at:
>
>
http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular
>
.nsf/1ab39b4ed563b08985256a35006d56af/e533bb05389c90e486256a54006e47b2/$FILE
> /Chapter%201-8.pdf
Try this one: http://tinyurl.com/qe6d
Vaughn
roger druce
a. Any use of the Schweizer release for a tow hook. >> It doesn't work
under high side loads. It is outdated and should be discarded. Use a Tost
release.
b. Any use of a rope along the fuselage for release actuation. >> Too
much stretch plus doesn't give you any force multiplication when things go
wrong and you need to ensure the ability of the tow pilot to release.
AC 43.13 Part 2A figure 8.3 shows a 5:1 lever. This is what you need to get
leverage and ensure that the tow pilot can release. But then also with a
lever there are issues with ensuring pilot access to the lever in emergency.
So a lot of thought as to the lever design and location is required.
AC43.13 Part 2A para 132c talks about 1/16" steel cable minimum. Again over
a long length this is too stretchy. Use 1/8" aircraft cable.
Try for best modern practice, not just using old data because it is
available.
A search of r.a.s archives will probably turn up more useful commentary.
Roger Druce
"Stuart Grant" <smg...@bellsouth.net> wrote in message
news:121d239b.03100...@posting.google.com...
Chip Fitzpatrick
believe our tow pilots would highly endorse the set up for safety
considerations.
contact me if you want to talk to someone about the approval process.
Chip Fitzpatrick
Rod Pool
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
W.J. (Bill) Dean (U.K.).
http://www.glidingmagazine.com/ListFeatureArticleDtl.asp?id=327 ,
by Chris Rollings.
Note also that the BGA has a modification to the Schweizer hook, approved
by the U.K. C.A.A., to incorporate a roller bearing in the hook to make
release under heavy load much easier.
W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.
>
> "Rod Pool" <rp...@midwestcc.net> wrote in message
> news:faaf6494.0310...@posting.google.com...
>
> Stuart
>
> Before using a Schweizer tow rig give serious consideration to the
> info on this website
>
> http://home.att.net/~jdburch/index.htm
>
> I too would recommend a tost tow rig only. Far safer for both the tow
Pete Brown
Stuart Grant
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
aasa...@gmail.com
Thank you for all the information. I am planning to install tow hook on our C180 in India. I badly need STC for installing hook otherwise local regulatory authority will not spar me. Please advise,How can get SSA copies of STC's issued to Javelin Aircraft Company for tow hook installation on Cessna 180. rasool...@gmail.com
regards
Ahmed
Curt Cole
>Hello Stuart,
>
>Thank you for all the information. I am planning to install tow hook on
Cessna
>180. rasool...@gmail.com=20
>
>regards
>Ahmed
> =20
>
>Should be Cessna Drawing #1291. Factory approved drawing, and AC43.13-2B,
Chapter 8 should do for "Approved Data.
rec.aviation.soaring
> Hello Stuart,
>
> Thank you for all the information. I am planning to install tow hook on our C180 in India. I badly need STC for installing hook otherwise local regulatory authority will not spar me. Please advise,How can get SSA copies of STC's issued to Javelin Aircraft Company for tow hook installation on Cessna 180.
>
> Ahmed
Ahmed,
Have you contacted the Soaring Society of America about getting copies of the STC SA65CE Drawing? The Soaring Society of America (SSA) owns the STC rights (like a patent) and you may need to buy an SSA membership or otherwise pay for the right to use the STC.
I have a poor quality scan of the drawing for the bracket which I got from the SSA. The STC was for a part (bracket) that was manufactured by Javelin Aircraft. The STC Drawing does not give all the dimensions needed to fabricate the bracket but I was able to fabricate a workable version from the drawing by using dimensions from the Scott Tail Wheel assembly on my Cessna 180.
The type of tow release that the STC is for was a Schweizer and a similar tow release is now manufactured by McFarlane Aviation Products (Part number 6029) See here: http://www.mcfarlane-aviation.com/pdfDocuments/6038%20Tow%20Hook%20Instructions.pdf
Here is a 2005 FAA Service Advisory Bulletin regarding the SA65CE STC: http://www.cessna.org/documents/public_info/saib/saib-ce-06-17.pdf
Here is a now-cancelled FAA Advisory Circular 43.13-2A about installation of Glider Tow Hooks:http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/list/AC%2043.13-2A/$FILE/Chapter%201-8.pdf
rec.aviation.soaring
> Hello Stuart,
>
> Thank you for all the information. I am planning to install tow hook on our C180 in India. I badly need STC for installing hook otherwise local regulatory authority will not spar me. Please advise,How can get SSA copies of STC's issued to Javelin Aircraft Company for tow hook installation on Cessna 180.
>
> Ahmed
Ahmed,
Curt's post above had a better link.
Look at the AC-43.13-2B this may be what you need: https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2043.13-2B.pdf
It has a photograph of the Cessna 180 Tow hitch Bracket
Stuart
craig....@gmail.com
>>>The SSA was kind enough to mail me nice copies of STC's issued to Javelin
If you still have copies they may be the only copies in existence. By any chance do you have copies of the Javelin drawings or any drawings from Gasser?
Thanks
Craig
rec.aviation.soaring
> Stuart
>
> >>>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
>
> The SSA have lost some of the pages required for the STC and Gasser is no longer in business and the company who bought them no longer have drawings of the bracket. I'm trying to help find them find what information exists.
>
> If you still have copies they may be the only copies in existence. By any chance do you have copies of the Javelin drawings or any drawings from Gasser?
>
> Thanks
>
> Craig
>
>
I think I have the complete STC for a towhook on Cessna 180 and 185. Who did you contact at the SSA? I prefer to end it to them so they will have it on file. They are the owner. Once they have it on file they can respond to requests.
Stuart