 |
Aviation Forums
Aviation discussions newsgroups
|
| View previous topic :: View next topic |
| Author |
Message |
Brad
Guest
|
 Posted: Sun Mar 08, 2009 5:03 pm Post subject: 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 |
|
| Back to top |
|
 |
Dan
Guest
|
| Posted: Sun Mar 08, 2009 5:23 pm Post subject: Re: motorgliders as towplanes |
|
|
On Mar 8, 10:03 am, Brad <apispi...@gmail.com> wrote:
| Quote: | 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 |
|
| Back to top |
|
|
Darryl Ramm
Guest
|
| Posted: Sun Mar 08, 2009 5:28 pm Post subject: Re: motorgliders as towplanes |
|
|
On Mar 8, 10:03 am, Brad <apispi...@gmail.com> wrote:
| Quote: | 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 |
|
| Back to top |
|
|
Guest
|
| Posted: Sun Mar 08, 2009 7:28 pm Post subject: Re: motorgliders as towplanes |
|
|
On Mar 8, 1:03 pm, Brad <apispi...@gmail.com> wrote:
| Quote: | 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. |
|
| Back to top |
|
|
Robert Danewid
Guest
|
| Posted: Sun Mar 08, 2009 9:12 pm Post subject: Re: motorgliders as towplanes |
|
|
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:
| Quote: | 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 |
|
|
| Back to top |
|
|
Craig Lowrie
Guest
|
| Posted: Sun Mar 08, 2009 9:12 pm Post subject: Re: motorgliders as towplanes |
|
|
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:
| Quote: | 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
|
|
|
| Back to top |
|
|
brianDG303
Guest
|
| Posted: Sun Mar 08, 2009 9:29 pm Post subject: Re: motorgliders as towplanes |
|
|
I'm struggling with a similar question, and it relates to rebuilds. I
guess different rebuilds cost very different amounts, and it seem that
a Pawnee rebuild is $35K and a little more. Could it be that a cheaper
to rebuild tow plane could be a better choice? |
|
| Back to top |
|
|
Martin Gregorie
Guest
|
| Posted: Sun Mar 08, 2009 10:23 pm Post subject: Re: motorgliders as towplanes |
|
|
On Sun, 08 Mar 2009 14:29:37 -0700, brianDG303 wrote:
| Quote: | I'm struggling with a similar question, and it relates to rebuilds. I
guess different rebuilds cost very different amounts, and it seem that a
Pawnee rebuild is $35K and a little more. Could it be that a cheaper to
rebuild tow plane could be a better choice?
|
Seems to me that you need to total up several factors:
1) The cost of replacing/rebuilding the tow plane
2) The cost of insuring the replacement for the time you'll keep it
3) The total operating cost for the time you'll keep it, i.e. include
both overhauls/part replacement as well as fuel and oil.
Then calculate the total cost per annum of each course of action.
--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org | |
|
| Back to top |
|
|
Darryl Ramm
Guest
|
| Posted: Sun Mar 08, 2009 11:53 pm Post subject: Re: motorgliders as towplanes |
|
|
On Mar 8, 3:23 pm, Martin Gregorie
<mar...@see.sig.for.address.invalid> wrote:
| Quote: | On Sun, 08 Mar 2009 14:29:37 -0700, brianDG303 wrote:
I'm struggling with a similar question, and it relates to rebuilds. I
guess different rebuilds cost very different amounts, and it seem that a
Pawnee rebuild is $35K and a little more. Could it be that a cheaper to
rebuild tow plane could be a better choice?
Seems to me that you need to total up several factors:
1) The cost of replacing/rebuilding the tow plane
2) The cost of insuring the replacement for the time you'll keep it
3) The total operating cost for the time you'll keep it, i.e. include
both overhauls/part replacement as well as fuel and oil.
Then calculate the total cost per annum of each course of action.
--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |
|
SO let's make it an even dozen.
Some other things that apply to all choices (including the Pawnee...)
4) who will maintain the tow plane, what experience on type/model do
they have and how many others doing similar things are available to
learn/get help from?
5) Vendor/product risk - a risk factor for chance the vendor will go
out of business or there will be a nasty AD etc. (yes nastier than the
spar mounts on Pawnee, and yes this risk applies to Pawnees etc. as
well)
6) Parts risks/costs - for some models where the vendor is no longer
making them, what is the risk parts won't be available, will be hard
to find or will be expensive to fabricate if at all possible? (And yes
this risk applies to Pawnees etc. as well, but is reduced somewhat by
their wide use)
7) Operational limitations - find out how whatever you are looking at
tows on the days you need to, on the surfaces, at the temperatures and
density altitudes etc. (e.g. more than a few motor gliders have
cooling issues when it gets hot outside).
 The expected TBO of the engine - I'd be pretty cautious about
assuming anything based on published TBOs - in general and especially
if the motorglider is towing. I'd go talk to real owners who have been
doing something similar. I have a lot less confidence in the engines
in some of these motorgliders doing as well there say compared to a
Lycoming in a Pawnee - but that is just my bias, unconfirmed by
reality either way. Bear in mind that with towing you may be putting a
lot more time on the engine than others so you'll be the canary in the
coal mine.
9) The utility at all of the motorglider as a XC glider/training
glider (you may just maintain it as a tow plane).
10) Insurance costs, pilot experience requirements and other issues. I
have no idea there, but I'd be calling my insurance agent early on in
the process (like now). Especially if some of the desire is to get
glider pilots with a motorglider endorsement towing - I cringe a bit
at that unless those folks have some power experience and/or a lot of
time in the motorglider.
11) Experimental category issues (if it's an experimental motorglider)
in the USA - I'd expect you would run into issues towing with
motorglider with an contest and exhibition certification.
12) You need to know that a tow release system is available or what
one involve/will cost to put through as a 337 only (if the FSDO would
do that?) and what issues that involves. One of the appeals of the tow
setup on many Pawnee's is the retractable tow rope. I'm guessing there
may not be space to install that in many motorgliders.
Anyhow just more brain food.
Darryl |
|
| Back to top |
|
|
Andreas Maurer
Guest
|
| Posted: Mon Mar 09, 2009 1:11 am Post subject: Re: motorgliders as towplanes |
|
|
On Sun, 8 Mar 2009 12:28:24 -0700 (PDT), silent2027 (AT) gmail (DOT) com wrote:
| Quote: | 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. |
|
| Back to top |
|
|
rlovinggood
Guest
|
| Posted: Mon Mar 09, 2009 1:13 am Post subject: Re: motorgliders as towplanes |
|
|
On Mar 8, 1:03 pm, Brad <apispi...@gmail.com> wrote:
| Quote: | 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
|
Brad,
Assuming we are talking about towing with MG in the US; can you get
insurance to do this?
Ray Lovinggood
Carrboro, NC, USA |
|
| Back to top |
|
|
Jim White
Guest
|
| Posted: Mon Mar 09, 2009 9:11 am Post subject: Re: motorgliders as towplanes |
|
|
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: |
|
| Back to top |
|
|
The Real Doctor
Guest
|
| Posted: Mon Mar 09, 2009 12:58 pm Post subject: Re: motorgliders as towplanes |
|
|
On 8 Mar, 17:03, Brad <apispi...@gmail.com> wrote:
| Quote: | Can a MG tug pull a loaded 2 place Blanik on a standard day at SL,
from a 1800' grass strip?
|
Mendip GC in the UK tows two seaters very successfully witha Rotax
Falke. As Andreas Maurer writes, initial acceleration is a little low
(a little? I damn nearly wet myself as the upwind wall approached) but
the climb feels like anything else.
Ian |
|
| Back to top |
|
|
Guest
|
| Posted: Mon Mar 09, 2009 3:14 pm Post subject: Re: motorgliders as towplanes |
|
|
On Mar 8, 1:03 pm, Brad <apispi...@gmail.com> wrote:
| Quote: | 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?
Brad
|
http://www.youtube.com/watch?v=5UYPyNgf4Q4
Lambada motorglider towing
UFM 13 Rotax 912 100hp |
|
| Back to top |
|
|
bildan
Guest
|
| Posted: Mon Mar 09, 2009 3:30 pm Post subject: Re: motorgliders as towplanes |
|
|
On Mar 9, 9:14 am, silent2...@gmail.com wrote:
| Quote: | On Mar 8, 1:03 pm, Brad <apispi...@gmail.com> wrote:
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?
Brad
http://www.youtube.com/watch?v=5UYPyNgf4Q4
Lambada motorglider towing
UFM 13 Rotax 912 100hp
|
I watched a Lambada tow an LS-3 from Boulder (elev 5300) on a hot day
and it looked about the same as the SSB 180HP Supercub. The LS-3
pilot reported the same. I can't speak to the maintainability of the
Lambada but keep in mind that the Pawnee isn't sterling in that
department either. |
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
