motorgliders as towplanes

I know this has come up before in RAS. But thought I would bring up
the subject again.

For a club looking at long term projections, which at some point will
include either sticking a "new" engine on a Pawnee or getting rid of
it, does it make sense to start evaluating getting a 2 place
motorglider to serve as a tug and also as a touring/training tool?

Can a MG tug pull a loaded 2 place Blanik on a standard day at SL,
from a 1800' grass strip? Or perhaps such a tug could be used to tow
the members single place ships, and the heavier/ 2-place ships stow
behind the clubs remaining pawnee?

We are blessed with 3 towplanes in our club, there are upcoming
factors that will/are causing us to look at several different
scenarios and am wondering if tossing a MG into the mix might be one
such solution.

Brad

On Mar 8, 10:03*am, Brad wrote:
I know this has come up before in RAS. But thought I would bring up
the subject again.

For a club looking at long term projections, which at some point will
include either sticking a "new" engine on a Pawnee or getting rid of
it, does it make sense to start evaluating getting a 2 place
motorglider to serve as a tug and also as a touring/training tool?

Can a MG tug pull a loaded 2 place Blanik on a standard day at SL,
from a 1800' grass strip? Or perhaps such a tug could be used to tow
the members single place ships, and the heavier/ 2-place ships stow
behind the clubs remaining pawnee?

We are blessed with 3 towplanes in our club, there are upcoming
factors that will/are causing us to look at several different
scenarios and am wondering if tossing a MG into the mix might be one
such solution.

Brad

I recently flew a Lambada and was very impressed with it's take off
and climb performance. We didn't tow any gliders so I can't report on
that. I flew the 80 HP version. We were at sea level, two 200+lbs
guys and only 80 HP, takeoff and climb performance seemed to be better
than a Super Cub. The 80 HP version isn't used for towing but the 100
HP version is. It is reported to have about as good as a 150 HP Super
Cub performance in towing. The Lambada soared pretty well, I was
really impressed. The L/D is claimed to be about 30/1 and that seemed
about right while gliding between thermals. It's a well thought out
little machine.
Check out Urban Air USA. My demo ride was with the very sailplane
experienced pilot Jim Lee. Great guy and a great team.

good luck,
Dan

On Mar 8, 10:03*am, Brad wrote:
I know this has come up before in RAS. But thought I would bring up
the subject again.

For a club looking at long term projections, which at some point will
include either sticking a "new" engine on a Pawnee or getting rid of
it, does it make sense to start evaluating getting a 2 place
motorglider to serve as a tug and also as a touring/training tool?

Can a MG tug pull a loaded 2 place Blanik on a standard day at SL,
from a 1800' grass strip? Or perhaps such a tug could be used to tow
the members single place ships, and the heavier/ 2-place ships stow
behind the clubs remaining pawnee?

We are blessed with 3 towplanes in our club, there are upcoming
factors that will/are causing us to look at several different
scenarios and am wondering if tossing a MG into the mix might be one
such solution.

Brad

You don't say what type of motorglider you are thinking of (seems even
sustainers count as motorgliders if you believe Soaring Magazine)

But having said that there is not one touring (i.e. non pylon style)
motorglider I can think of that I'd want to tow behind in any
sailplane, well certainly not a two place glider. A Kstana or
something with a big engine might be able to tow a light glider but it
is not going to touch a good Pawnee or simmilar and so what then you
are left with a not great tug and a not very good XC trainer (or XC
anything). But I don't understimate how the appeal of being flexible/
multi-purpose and doing something clever/different might just suck
people in...

As a self-launch motorglider owner in general I tend to think good XC
trainers do *not* have motors. Think Duo Discus or DG-1000S class two
seater. Motorgliders are compelx and expensive to operate and most
have more vices than a modern two-seater, so you are not going to let
newer pilots (the very ones you want to be encouraging to go XC) go
fly them solo etc. And if you only do dual in that glider and send
them solo in an a conventional glider you are sending the XC student/
mentoree a very bad signal.

Motorgliders can be great for some things, inluding orientatiion
flights, etc. but you can also do those in a two place power plane.

Darryl

We spent quite some time looking at this. We currently have 2xPawnee 235's
and a Super Cub 180. We also have a Falke 2000 motorglider. Normally we
only need on tug, except on busy periods when we occationally need two.
The motorglider is underutilised, so the idea of a motorglider that can
tow seemed attractive.

To keep operations simple, we assumed that one of our Pawnees would be
servicable, so that the Motorglider could tow single seaters (which is
usually the cause of our peak demand), and therefore the utilisation of
the motorised fleet would increase and we would need one less aircraft.

Initially we evaliated the 100hp fixed pitch Rotax Falke. It did tow, but
seemed a bit marginal from our operation. Also it needed careful
management of the engine temperature to avoid long term issues.

Then we looked at the Grob 109 Turbo. This gives about 130hp for the
initial takeoff and was substantially better than the Falke whilst still
delivering economy which was more than two times better than the Pawnee. I
would say that it was the best we looked at and also better than the super
dimona, which we also studied briefly.

In the UK a G109T has been towing from a grass strip for almost two years
now, towing a variety of single and two seat gliders (including duo's
etc) and has very few problems, I understand.

The concept is certainly worth considering. In the meantime, we continue
to watch developments, as well as plans to re-engine Pawnees with 230hp
Diesel Engines.

Craig Lowrie, UK

At 17:28 08 March 2009, Darryl Ramm wrote:
On Mar 8, 10:03=A0am, Brad wrote:
I know this has come up before in RAS. But thought I would bring up
the subject again.

For a club looking at long term projections, which at some point will
include either sticking a "new" engine on a Pawnee or getting rid of
it, does it make sense to start evaluating getting a 2 place
motorglider to serve as a tug and also as a touring/training tool?

Can a MG tug pull a loaded 2 place Blanik on a standard day at SL,
from a 1800' grass strip? Or perhaps such a tug could be used to tow
the members single place ships, and the heavier/ 2-place ships stow
behind the clubs remaining pawnee?

We are blessed with 3 towplanes in our club, there are upcoming
factors that will/are causing us to look at several different
scenarios and am wondering if tossing a MG into the mix might be one
such solution.

Brad

You don't say what type of motorglider you are thinking of (seems even
sustainers count as motorgliders if you believe Soaring Magazine)

But having said that there is not one touring (i.e. non pylon style)
motorglider I can think of that I'd want to tow behind in any
sailplane, well certainly not a two place glider. A Kstana or
something with a big engine might be able to tow a light glider but it
is not going to touch a good Pawnee or simmilar and so what then you
are left with a not great tug and a not very good XC trainer (or XC
anything). But I don't understimate how the appeal of being flexible/
multi-purpose and doing something clever/different might just suck
people in...

As a self-launch motorglider owner in general I tend to think good XC
trainers do *not* have motors. Think Duo Discus or DG-1000S class two
seater. Motorgliders are compelx and expensive to operate and most
have more vices than a modern two-seater, so you are not going to let
newer pilots (the very ones you want to be encouraging to go XC) go
fly them solo etc. And if you only do dual in that glider and send
them solo in an a conventional glider you are sending the XC student/
mentoree a very bad signal.

Motorgliders can be great for some things, inluding orientatiion
flights, etc. but you can also do those in a two place power plane.

Darryl

Hi Craig.

I landed out at Sackville Farm in the 15s last year and was ear bashed for
about an hour by Tim on how good the Grob109T was for towing. Unfortunately
he was not able to give me a tow out as the undercarriage had been damaged
and it was in repair.

I think you need a very good surface to operate off and that the Grob (and
probably similar SLMGs) are too lightly built for anything more than
occasional tugging.

At BGC our tugs do c. 2000 cycles p.a. each. I doubt that a MG would stay
that pace.

Jim


At 18:00 08 March 2009, Craig Lowrie wrote:

On 9 Mar 2009 08:30:04 GMT, Jim White wrote:


I think you need a very good surface to operate off and that the Grob (and
probably similar SLMGs) are too lightly built for anything more than
occasional tugging.

Their strength is completely sufficient for towing all dyearlong -
lots of clubs in Germany are using motorgliders as their primary tug
plane. The only problem is that they usually need a long grass or a
paved runway to be safe.



At BGC our tugs do c. 2000 cycles p.a. each. I doubt that a MG would stay
that pace.

No problem at all for a motorglider.

In message , Jim White
writes
Hi Craig.

I landed out at Sackville Farm in the 15s last year and was ear bashed for
about an hour by Tim on how good the Grob109T was for towing. Unfortunately
he was not able to give me a tow out as the undercarriage had been damaged
and it was in repair.

I think you need a very good surface to operate off and that the Grob (and
probably similar SLMGs) are too lightly built for anything more than
occasional tugging.


I also landed there last year and got a ride with Tim in his Grob. He
also did a tow for another arrival from Shennington who wasn't feeling
too euphoric to fly back.

Apparently the same one visited my own club the previous year to
demonstrate how good it was a towing, and they gave it our heaviest
two-seater with one of our heaviest crew combos, and it got them off the
ground. I believe our aerotow strip is just shy of 800m, and it rises
slightly at the end they took off towards. So far as I know the Grob
performed admirably.

At BGC our tugs do c. 2000 cycles p.a. each. I doubt that a MG would stay
that pace.

--
Surfer!
Email to: ramwater at uk2 dot net

On Mar 8, 1:03*pm, Brad wrote:
I know this has come up before in RAS. But thought I would bring up
the subject again.

For a club looking at long term projections, which at some point will
include either sticking a "new" engine on a Pawnee or getting rid of
it, does it make sense to start evaluating getting a 2 place
motorglider to serve as a tug and also as a touring/training tool?

Can a MG tug pull a loaded 2 place Blanik on a standard day at SL,
from a 1800' grass strip? Or perhaps such a tug could be used to tow
the members single place ships, and the heavier/ 2-place ships stow
behind the clubs remaining pawnee?

We are blessed with 3 towplanes in our club, there are upcoming
factors that will/are causing us to look at several different
scenarios and am wondering if tossing a MG into the mix might be one
such solution.

Brad

I remember reading about a Pipistrel Sinus motorglider towing an LS8
to 2400 feet AGL in 6 minutes in Italy.............
I assume that a lighter gliders should climb even better!
There is also a video on Youtube showing a Lambada motorglider
towing a double seater metal glider.
The Sinus with an 80 HP Rotax
The Lambada with a 100 HP Rotax
Motorgliders will tow into the future!!!!!
Maybe at 3 gallons an hour car fuel.

On Sun, 8 Mar 2009 12:28:24 -0700 (PDT), wrote:


I remember reading about a Pipistrel Sinus motorglider towing an LS8
to 2400 feet AGL in 6 minutes in Italy.............
I assume that a lighter gliders should climb even better!
There is also a video on Youtube showing a Lambada motorglider
towing a double seater metal glider.
The Sinus with an 80 HP Rotax
The Lambada with a 100 HP Rotax
Motorgliders will tow into the future!!!!!
Maybe at 3 gallons an hour car fuel.


Once airborne a 100hp tow plane (motorglider, ultralight) climbs well,
even with a heavy double seater in tow.

The limiting factor is initial acceleration - high density altitudes
and muddy gound might prevent a safe tow.
In my opinion a paved runway is necessary if you want safe tows even
at high density altitudes.

In Sweden it is quite common to use Super Dimonas as tugs and we tow two
seaters with no problem. Climb rate is like a 150 hp PA-18. But the
ground run is a bit longer.

The big advantages are less fuel consumption and that that you can tow
with a gliding license only.

Robert
ASW 28-18E
RD


Brad skrev:
I know this has come up before in RAS. But thought I would bring up
the subject again.

For a club looking at long term projections, which at some point will
include either sticking a "new" engine on a Pawnee or getting rid of
it, does it make sense to start evaluating getting a 2 place
motorglider to serve as a tug and also as a touring/training tool?

Can a MG tug pull a loaded 2 place Blanik on a standard day at SL,
from a 1800' grass strip? Or perhaps such a tug could be used to tow
the members single place ships, and the heavier/ 2-place ships stow
behind the clubs remaining pawnee?

We are blessed with 3 towplanes in our club, there are upcoming
factors that will/are causing us to look at several different
scenarios and am wondering if tossing a MG into the mix might be one
such solution.

Brad