Lowest power tow

Well, let's see...Â* There are self launching gliders, winches, ground
launches, bungee, gravity...Â* We're really spoiled in the US with our
aero tows.Â* How about an air boat?

On 1/20/2020 7:34 AM, wrote:
"Is it time to design the sailplane towing version of the Dragonfly for when we run out of Pawnees? Be interesting to see what the soaring brain trust could come up with."

If only there was a way to get gliders in the air that didn't require dangerous and expensive rare airplanes... if only there was a "brain trust" elsewhere in the world we could look to for answers. Sigh... well it looks like we're alone with this mystery.

--
Dan, 5J

On Monday, 20 January 2020 06:37:06 UTC-7, wrote:
On Sunday, January 19, 2020 at 9:20:04 AM UTC-5, Ron Gleason wrote:
On Saturday, 18 January 2020 22:30:51 UTC-7, wrote:
What's the lowest power tow plane you've ever seen or towed by? An Examiner of mine said his was a C150 with 100hp. I also once saw paperwork for an 85hp Luscombe to tow.

Dragonfly Ultralight used to tow hang gliders, equipped with Rotax 914S.. Towed my DG303 at Big SPring TX during the 2008 HG worlds so we could assist the organizers with spotting 'cloud flyers' amongst the competitors.

Many gliders have been towed out of Sheets airport, north of Seminole, when they landed short getting back to Seminole.

We have a turbo Dragonfly at our place. Lots of power but a slow airplane.. How fast was your tow speed behind the Dragonfly?
UH

I believe I lifted off the runway around 50 MPH and we towed between 48-55 MPH. The maximum speed of a Dragonfly is around 62 MPH according to the designer Bobbie Ballie due to the airfoil and all the drag.

Used lots of runway ~2,000 ft, the Dragonfly takes off within 100 feet of TO roll so the tow pilot has to stay low as speed increases. Glider pilot has to be patient to stay on the ground till desired speed and yes you are looking up at the Dragonfly. I kept low tow position for maximum visibility and to 'follow' the Dragonfly as it moved around.

Yes the Dragonfly is very lite weight and it is easy to disrupt it. The conditions at Big Spring are strong thermic so yes I threw the Dragonfly around a few times. Plus we only towed to 1,500 AGL as conditions were quite good to get away.

The Dragonfly pilot was Russell Brown, IMHO one of the top 5 Dragonfly pilots and mechanics in the world so I had confidence there.

Other folks have used the Dragonfly as a tow ship, Gary Osaba in Zapata TX towed a Silent, Sparrowhawk and others. In Zapata we accomplished dual HG tows with the Dragonfly and I believe a few triple tows to 3,000 AGL.

I would not try this at higher elevations with high density altitudes.

The Dragonfly pilot was Russell Brown, IMHO one of the top 5 Dragonfly pilots and mechanics in the world so I had confidence there.

Other folks have used the Dragonfly as a tow ship, Gary Osaba in Zapata TX towed a Silent, Sparrowhawk and others. In Zapata we accomplished dual HG tows with the Dragonfly and I believe a few triple tows to 3,000 AGL.

I would not try this at higher elevations with high density altitudes.

With higher density altitudes, the turbo-914 is OK but as Ron has noted the tow speeds are limited with the Dragonfly. The normally aspirated Dragonfly's would be challenged at the higher density altitudes. I've had good, but careful tows from Russell Brown, Bobby Bailey, and Rhett Radford in Dragonfly's towing half a dozen types of lighter gliders. The turbo-914 has successfully towed my ASW-27B many times, but dry. It was borderline, and both pilots really need to know what they are doing.

The lowest powered tows I've experienced were behind a flex-wing Trike, forgotten make, flown by Neal Harris with a Rotax 377 and 35 hp at Hearne, TX. With this, we set two World Records in a Woodstock I- out and return distance and 100km speed triangle for DU class gliders. These were later eclipsed by more modern designs.

As another poster wrote, Garland Pack's early work in this area is notable. A cogent paper was written showing the effectiveness of completely stripping the tow plane to reduce all unnecessary weight- and matching props to the job. I have a copy somewhere but cannot locate it right now. As another poster wrote, the key figure of merit here is excess power. Penaud diagrams are effective in portratying the pertinent relationships and variables.

Please do not construe any of this as a general recommendation. More power = more safety, more options.

Gary Osoba

On Monday, January 20, 2020 at 12:23:46 PM UTC-5, wrote:
The Dragonfly pilot was Russell Brown, IMHO one of the top 5 Dragonfly pilots and mechanics in the world so I had confidence there.

Other folks have used the Dragonfly as a tow ship, Gary Osaba in Zapata TX towed a Silent, Sparrowhawk and others. In Zapata we accomplished dual HG tows with the Dragonfly and I believe a few triple tows to 3,000 AGL.

I would not try this at higher elevations with high density altitudes.

With higher density altitudes, the turbo-914 is OK but as Ron has noted the tow speeds are limited with the Dragonfly. The normally aspirated Dragonfly's would be challenged at the higher density altitudes. I've had good, but careful tows from Russell Brown, Bobby Bailey, and Rhett Radford in Dragonfly's towing half a dozen types of lighter gliders. The turbo-914 has successfully towed my ASW-27B many times, but dry. It was borderline, and both pilots really need to know what they are doing.

The lowest powered tows I've experienced were behind a flex-wing Trike, forgotten make, flown by Neal Harris with a Rotax 377 and 35 hp at Hearne, TX. With this, we set two World Records in a Woodstock I- out and return distance and 100km speed triangle for DU class gliders. These were later eclipsed by more modern designs.

As another poster wrote, Garland Pack's early work in this area is notable. A cogent paper was written showing the effectiveness of completely stripping the tow plane to reduce all unnecessary weight- and matching props to the job. I have a copy somewhere but cannot locate it right now. As another poster wrote, the key figure of merit here is excess power. Penaud diagrams are effective in portratying the pertinent relationships and variables.

Please do not construe any of this as a general recommendation. More power = more safety, more options.

Gary Osoba

The Garland Pack tugs were the topic of a Soaring magazine article.
Searching the archive should find it.
UH

On Sunday, January 19, 2020 at 12:30:51 AM UTC-5, wrote:
What's the lowest power tow plane you've ever seen or towed by? An Examiner of mine said his was a C150 with 100hp. I also once saw paperwork for an 85hp Luscombe to tow.

My club used to own a British-made Taylorcraft 'Auster'. It had an inverted inline four (or six? - can't remember) engine which seemed very underpowered. We soon switched to a 150HP Super-Cub, which made a huge difference.

Uli
'AS'

On Sun, 19 Jan 2020 08:06:08 -0800, AS wrote:

On Sunday, January 19, 2020 at 12:30:51 AM UTC-5,
wrote:
What's the lowest power tow plane you've ever seen or towed by? An
Examiner of mine said his was a C150 with 100hp. I also once saw
paperwork for an 85hp Luscombe to tow.

My club used to own a British-made Taylorcraft 'Auster'. It had an
inverted inline four (or six? - can't remember) engine which seemed very
underpowered. We soon switched to a 150HP Super-Cub, which made a huge
difference.

That engine would have been the De Havilland Gypsy Major, 130hp, four
cylinder inverted. It was fitted to a lot of 30s and 40s DH designs as
well as the Auster III, the most common Auster variant.

A lot of towing in the mid-50s in NZ, and probably in Britain as well,
was done with DH82 Tiger Moths, which all used the 130hp Gypsy Major
engine. As ex-wartime primary trainers they were plentiful and very
cheap. IIRC around 1950 you could pick them up for £25 in Britain. They
were also very common in Australia and NZ, where a lot were crashed in
early attempts at spreading superphosphate by air on hill pastures[*].

In 1958, in NZ, I remember getting a ride in a Schleicher
Ka-4 Rhonlerche. That was an aero-towed launch behind a Tiger Moth.
[*] Several years later, when Tiger Moths had been replaced by the
Fletcher FU-24 as the topdressing aircraft of choice, I remember seeing a
Cessna 180 with a bomb rack under each wing - this was an ill-advised
attempt to deliver fencing material on hill farms, the 'bomb' being a
bundle of angle-iron fence posts, etc. The problem was that the bundles
either arrived end-on and went in so far that it wasn't worth digging
them out or they landed sideways and rolled down to the bottom of the
hill, from where the farmer had to use a tractor/jeep/pack-horse to cart
them up the hill to where they were wanted. It was simpler and cheaper to
cart the fencing material up the hill along the same track the fencers
used, so that delivery method as soon abandoned.


--
Martin | martin at
Gregorie | gregorie dot org

In the 1960's-70's my Dad, Fritz Compton, would tow me in our Cirrus(Open Class) out of our 1,900' grass runway gliderport south of Miami, FLA using a 65 HP Piper J3 Cub with a climb prop. Later we upgraded to a 100 HP 1959 Cessna 150 with a climb prop. If the grass is tightly mowed, the glider pilot is very smooth on the controls (to minimize drag) and a discussion of a mandatory abort point is accomplished, it worked for us but You must evaluate and make your own decision!

My other "slow tow" experiences include aerotows in Germany behind motorgliders and the European category of ultralight airplanes.

The legendary Dick Johnson told me at a Marfa Wave Camp that he preferred a lower powered towplane because a slow climb on tow allowed him to evaluate and mark the thermals before release.

Those "old school" aviators had some interesting ideas and observations. Ask me sometime about my Dad's observation of the engine sound of an airplane flying overhead on a cold day - how the sound can indicate if thermals are present and if we should launch. Dad also observed that hawks and eagles often flew in the core of a thermal but buzzards and vultures preferred a slower climb on the edge of a thermal. True or not, soaring is primarily about the observations you make by looking outside.

Looking forward to further discussions at the SSA Convention in Little Rock, FEB 19-22, 2020.
Find me at the Soaring Safety Foundation booth near the entrance to the convention hall.

On Saturday, January 18, 2020 at 10:30:51 PM UTC-7, wrote:
What's the lowest power tow plane you've ever seen or towed by? An Examiner of mine said his was a C150 with 100hp. I also once saw paperwork for an 85hp Luscombe to tow.

Essex & Suffolk GC had an Auster A5J and a Rollason Condor D.62C (130hp). After a mishap with the Auster, the club acquired another Condor D.62A (100hp). The A version only towed single seaters. I could see the stall warning light going on and off in the Condor panels at times from the glider end..

I believe the benchmark lowest power tow was by a 1600 VW powered D31
Turbulent, from the Tiger Club at Redhill, UK, in the 1960's. A 15m
Slingsby Dart
was the victim. The tow was never repeated.


At 19:09 19 January 2020, Frank Whiteley wrote:
On Saturday, January 18, 2020 at 10:30:51 PM UTC-7,
wro=
te:
What's the lowest power tow plane you've ever seen or towed by? An
Examin=
er of mine said his was a C150 with 100hp. I also once saw paperwork for
an=
85hp Luscombe to tow.

Essex & Suffolk GC had an Auster A5J and a Rollason Condor D.62C (130hp).

=
After a mishap with the Auster, the club acquired another Condor D.62A
(100=
hp). The A version only towed single seaters. I could see the stall
warni=
ng light going on and off in the Condor panels at times from the glider
end=
..

On Sunday, January 19, 2020 at 12:30:51 AM UTC-5, wrote:
What's the lowest power tow plane you've ever seen or towed by? An Examiner of mine said his was a C150 with 100hp. I also once saw paperwork for an 85hp Luscombe to tow.

I once took a tow in my HP-14 behind a Citabria or Luscombe. I don't know the horsepower - that plane had a tow hook mostly for use towing banners. It was a wild windy wave day and the tow seemed to take forever as I was using full-control-deflections in all directions in the turbulence. After release at 4000 AGL or so I hit consistent sink and beat the towplane back to the airport.