Tow plane types/mods for high density altitude glider towing

On Monday, August 12, 2019 at 7:38:43 PM UTC-6, son_of_flubber wrote:
What are your favorite aircraft types (and modifications) for glider towing in high density altitude and/or short runways?

Mark Keene once told me about towing with one of these at Uvalde making a 2000ft tow and return in under three minutes. https://en.wikipedia.org/wiki/SIAI-Marchetti_SM.1019

28 variants on the US registry.

Frank Whiteley

On Tuesday, August 13, 2019 at 2:57:24 PM UTC-4, Frank Whiteley wrote:
On Monday, August 12, 2019 at 7:38:43 PM UTC-6, son_of_flubber wrote:
What are your favorite aircraft types (and modifications) for glider towing in high density altitude and/or short runways?

Mark Keene once told me about towing with one of these at Uvalde making a 2000ft tow and return in under three minutes. https://en.wikipedia.org/wiki/SIAI-Marchetti_SM.1019

28 variants on the US registry.

Frank Whiteley

I towed behind Mark in my '28. We had 2000 feet in 1:40. He told me he was using 40% power.
UH

On Tuesday, August 13, 2019 at 1:42:14 PM UTC-6, wrote:
On Tuesday, August 13, 2019 at 2:57:24 PM UTC-4, Frank Whiteley wrote:
On Monday, August 12, 2019 at 7:38:43 PM UTC-6, son_of_flubber wrote:
What are your favorite aircraft types (and modifications) for glider towing in high density altitude and/or short runways?

Mark Keene once told me about towing with one of these at Uvalde making a 2000ft tow and return in under three minutes. https://en.wikipedia.org/wiki/SIAI-Marchetti_SM.1019

28 variants on the US registry.

Frank Whiteley

I towed behind Mark in my '28. We had 2000 feet in 1:40. He told me he was using 40% power.
UH

Now that I think about it, I believe Mark said his tow cycle time was 2.5 minutes. Must have been an interesting view from the glider;^)

Frank

Regarding mods, the eTug deserves mention.
A Pawnee with a 350 cubic inch Chevy LS1 running on Mogas. Early experiments provided too steep a climb angle, so the original 4-blade prop was adjusted to decrease the climb rate. Now it has a different prop.
I've hooked many gliders up to eTug, yet to tow behind it.

https://www.glidingclub.org.au/membe...aircraft/etug/

These days a crate LS3 engine can be purchased for about $8000 and produces 430HP on Mogas. Car engines require a PSRU (speed reduction).

https://www.gmperformancemotor.com/p... AhPlEALw_wcB

Not much concern about shock cooling or leaded Avgas going away.
Jim

At 20:08 13 August 2019, JS wrote:
Regarding mods, the eTug deserves mention.
A Pawnee with a 350 cubic inch Chevy LS1 running on Mogas. Early
experiments provided too steep a climb angle, so the original 4-blade
prop
was adjusted to decrease the climb rate. Now it has a different prop.
I've hooked many gliders up to eTug, yet to tow behind it.

https://www.glidingclub.org.au/membe...aircraft/etug/

These days a crate LS3 engine can be purchased for about $8000 and
produces
430HP on Mogas. Car engines require a PSRU (speed reduction).

https://www.gmperformancemotor.com/parts/19370416.html?
gclid=Cj0KCQjwv8nqBRDGARIsAHfR9wC30A7wF3SFSrhYOBoL dkinr_7M
GZMpHxignUEhA1qfW5iBSSEbHwAaAhPlEALw_wcB

Not much concern about shock cooling or leaded Avgas going away.
Jim

A Zlin Z-137t would seam to do the job. This is turbine powered and
there is a video on U tube of one towing 9 x L13 Blanics in one tow.

That is super!

Was there any difficulty with your CAA or was the GFA authorized to make
those mods?

On 8/13/2019 2:08 PM, JS wrote:
Regarding mods, the eTug deserves mention.
A Pawnee with a 350 cubic inch Chevy LS1 running on Mogas. Early experiments provided too steep a climb angle, so the original 4-blade prop was adjusted to decrease the climb rate. Now it has a different prop.
I've hooked many gliders up to eTug, yet to tow behind it.

https://www.glidingclub.org.au/membe...aircraft/etug/

These days a crate LS3 engine can be purchased for about $8000 and produces 430HP on Mogas. Car engines require a PSRU (speed reduction).

https://www.gmperformancemotor.com/p... AhPlEALw_wcB

Not much concern about shock cooling or leaded Avgas going away.
Jim

--
Dan, 5J

On Wednesday, August 14, 2019 at 7:33:57 AM UTC-7, Dan Marotta wrote:
That is super!

Was there any difficulty with your CAA or was the GFA authorized to make
those mods?

On 8/13/2019 2:08 PM, JS wrote:
Regarding mods, the eTug deserves mention.
A Pawnee with a 350 cubic inch Chevy LS1 running on Mogas. Early experiments provided too steep a climb angle, so the original 4-blade prop was adjusted to decrease the climb rate. Now it has a different prop.
I've hooked many gliders up to eTug, yet to tow behind it.

https://www.glidingclub.org.au/membe...aircraft/etug/

These days a crate LS3 engine can be purchased for about $8000 and produces 430HP on Mogas. Car engines require a PSRU (speed reduction).

https://www.gmperformancemotor.com/p... AhPlEALw_wcB

Not much concern about shock cooling or leaded Avgas going away.
Jim

--
Dan, 5J

Akaflieg Stuttgart just flew their concept of an optimized towplane. Congratulations to all the students and their mentors.

https://akaflieg.hg.stuvus.uni-stutt...EvgsGCyBGeZLCI

Craig

On Wednesday, August 14, 2019 at 10:35:01 AM UTC-6, Craig Funston wrote:
On Wednesday, August 14, 2019 at 7:33:57 AM UTC-7, Dan Marotta wrote:
That is super!

Was there any difficulty with your CAA or was the GFA authorized to make
those mods?

On 8/13/2019 2:08 PM, JS wrote:
Regarding mods, the eTug deserves mention.
A Pawnee with a 350 cubic inch Chevy LS1 running on Mogas. Early experiments provided too steep a climb angle, so the original 4-blade prop was adjusted to decrease the climb rate. Now it has a different prop.
I've hooked many gliders up to eTug, yet to tow behind it.

https://www.glidingclub.org.au/membe...aircraft/etug/

These days a crate LS3 engine can be purchased for about $8000 and produces 430HP on Mogas. Car engines require a PSRU (speed reduction).

https://www.gmperformancemotor.com/p... AhPlEALw_wcB

Not much concern about shock cooling or leaded Avgas going away.
Jim

--
Dan, 5J

Akaflieg Stuttgart just flew their concept of an optimized towplane. Congratulations to all the students and their mentors.

https://akaflieg.hg.stuvus.uni-stutt...EvgsGCyBGeZLCI

Craig

That looks promising. Now to make them "affordable".

On Wed, 14 Aug 2019 09:34:59 -0700, Craig Funston wrote:

On Wednesday, August 14, 2019 at 7:33:57 AM UTC-7, Dan Marotta wrote:
That is super!

Was there any difficulty with your CAA or was the GFA authorized to
make those mods?

On 8/13/2019 2:08 PM, JS wrote:
Regarding mods, the eTug deserves mention.
A Pawnee with a 350 cubic inch Chevy LS1 running on Mogas. Early
experiments provided too steep a climb angle, so the original 4-blade
prop was adjusted to decrease the climb rate. Now it has a different
prop.
I've hooked many gliders up to eTug, yet to tow behind it.

https://www.glidingclub.org.au/membe...aircraft/etug/

These days a crate LS3 engine can be purchased for about $8000 and
produces 430HP on Mogas. Car engines require a PSRU (speed
reduction).

https://www.gmperformancemotor.com/parts/19370416.html?
gclid=Cj0KCQjwv8nqBRDGARIsAHfR9wC30A7wF3SFSrhYOBoL dkinr_7MGZMpHxignUEhA1qfW5iBSSEbHwAaAhPlEALw_wcB

Not much concern about shock cooling or leaded Avgas going away.
Jim

--
Dan, 5J

Akaflieg Stuttgart just flew their concept of an optimized towplane.
Congratulations to all the students and their mentors.

https://akaflieg.hg.stuvus.uni-stutt...erstflug-fs35-
harpyie/?
fbclid=IwAR1rgq8zp1xdRFvQTqvAQGbklVeiF76CE0bKvKbdx jlFvEvgsGCyBGeZLCI

I remember a couple of specialist tow planes appearing a few years ago,
apparently to disappear without trace a bit later. One came from an
Akaflieg and was dual purpose: two seat aerobatic aircraft and tow-plane.
The other was from the Finnish Akaflieg equivalent - the PIK-27.

Are either in use as tow-planes now?

Has more than the prototype of either type been built?


--
Martin | martin at
Gregorie | gregorie dot org

The Mü30 Schlacro from Akaflieg Munich is in use and serves as an excellent towplane. Schlacro comes from "Schlepp" (Tow) and "Acro". It will probably be around at WGC 2020 at Stendal. Currently it is working there during Idaflieg summer camp. Since it was built by the students, it unfortunately is a unique aircraft.

The fs35 is a very interesting concept indeed, combining a motorglider similar to a HK36 Super Dimona with a 155hp turbocharged aircraft diesel engine..