Auto-Towing - why is this not more popular?

At 04:29 06 October 2015, Frank Whiteley wrote:
On Monday, October 5, 2015 at 7:32:02 PM UTC-6, Sean Fidler wrote:
From the guy who ran the Cadilac auto-tow camp last year...
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"Auto-tow pointers" - Cadillac, MI camp
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Gliders: ASW12, ASK21, ASW15, RS15, and some others =20
Tow vehicle: Late model Ford Fairmont, V8, 305 cubic inch=20
Tow rope: Initially, dacron 1500 ft The next year spectra 1500ft
Runway length 5200 ft (field elevation - 800 msl)
Average altitude gain 1000 to 1200 ft (occasionally 1500ft)=20
Get away rate for cross country: 75%
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Highlights: =20
Six pilots auto-tow launch endorsed in one day and a 12-year annual
(Than=
k you Stan & Carol)
Over 100 hours of XC in the 12 from auto-tow in 1 yr=20
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Lowlights: introduced to a club with many solo pilots, not many tow
pilo=
ts, and left the unit with them for a year. They never used it!
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Auto-Tow unit description: 1500 ft.rope on a reel powered by a Ford
star=
ter motor 1950's vintage (exposed shaft beyond motor housing)
controlled
by=
a dead man type switch. Reel in time about 1 minute. Easily fits in
trun=
k. The emergency release mechanism is a larger copy of Schweizer tow
relea=
se mounted to a hitch with a rope to the driver. The driver has radio
comm=
unication to glider. The driver is any person that is willing. The
driver=
is instructed to accelerate smoothly until glider lifts off and then add
5=
mph unless told otherwise. Normally, this meant (after glider lift off)
fu=
ll to the floorboard (and to remember that the runway does have an
end!). =
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For those of you that think this technique is not proper well, ok. For
t=
hose that are willing, this is a way to launch sailplane with: 1) less
cost=
and 2) no need for a tow pilot or tow aircraft. This auto-towing
techniqu=
e is ideal for any "club" with a willing group of two or more. Oh yes,
the=
safety checks were performed on all gliders used. They all had properly
f=
unctioning, carefully inspected tow releases. =20
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Sean (still shaking my head at the sidenote).
7T

The former Enstone GC in the UK used autotow for several years. Parafil
wa=
s used as it could be dragged along the tarmac without appreciable
wear.
P=
arafil is not pulley friendly (they tried). It was easily spliced.
Case study,
http://linearcomposites.net/media/pa...e_study_13.pdf

The club moved on to winches before we wore out the parafil. 1500ft
plus
l=
aunches were done on a 500m length using an XJ-6 Jaguar with 275hp.
We
jus=
t pulled it back to the launch point at 65mph. Near tangled though we
did
=
snag a couple of things in the tall grass on the north side of the
runway.

That engine replaced the 150hp Bedford diesel in one of the ex-ATC
winches.=
Another winch was refitted with the motor and transmission from a
stolen
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Rolls Royce that was burned on the airfield one night.

I don't think the third ex-ATC winch was ever put into service before the
c=
lub folded.

Maybe some lurker knows the fate of those winches.

Frank Whiteley


For info
The winch with RR engine is at north wales gliding club,
our other winch destroyed it,s gearbox on sunday so the Rolls Royce is to
be put back to work this weekend with some luck.
KF