Vans RV-11

"
Gliders are extremely elegant and clean.
Turbines are also quite elegant and reliable,
with the only drawback being fuel consumption.
For self-launch gliders this is not very
important, since only minutes
of climb are needed anyway.

I agree with much of what you say but fuel consumption is actually important
to get the full utility of a self launcher. If you want to do a tour for
example and go from place to place then you often need to relaunch without
refuelling or you may want to cruise a while to get into wave or good
soaring. If you go on a long task and totally misjudge the weather you may
need forty minutes of engine time and most of your fuel in a petrol engine
machine just to get home.

John Mason wrote:

I agree with much of what you say but fuel consumption is actually important
to get the full utility of a self launcher. If you want to do a tour for
example and go from place to place then you often need to relaunch without
refuelling or you may want to cruise a while to get into wave or good
soaring. If you go on a long task and totally misjudge the weather you may
need forty minutes of engine time and most of your fuel in a petrol engine
machine just to get home.

A mini-turbine glider would really be a true self-launcher. It
would not be a multi-launcher or sustainer (due to the fuel
consumption). But fuel is quite easily available, and it isn't
much of a stretch to pick airports with fuel as landouts,
or have an FBO hold on to a can of it for you, or have crew bring
you some. A mini-turbine would be very similar
to an aerotow in capabilities and limitations...

Using a motorglider the way you mention is quite useful and
practical and flexible. On the other hand, that technique
makes me consider those applications as just flying an
airplane that has a very high glide ratio and turning off
the engine sometimes. I'd be very willing to forego that
option to avoid icky pylons and props and unreliability.

Mark James Boyd wrote:

A mini-turbine glider would really be a true self-launcher. It
would not be a multi-launcher or sustainer (due to the fuel
consumption). But fuel is quite easily available, and it isn't
much of a stretch to pick airports with fuel as landouts,
or have an FBO hold on to a can of it for you, or have crew bring
you some. A mini-turbine would be very similar
to an aerotow in capabilities and limitations...

Using a motorglider the way you mention is quite useful and
practical and flexible. On the other hand, that technique
makes me consider those applications as just flying an
airplane that has a very high glide ratio and turning off
the engine sometimes.

Bad analogy, because the ratio of soaring to engine time is still very
high - even my longest retrieve still had 3 hours of soaring and only 40
minutes of engine for about 140 return. No one else flew from our
airport, because the bad air had already arrived when I left.

I'd be very willing to forego that
option to avoid icky pylons and props and unreliability.

You don't have to wait for turbines to get this ability (simplicity and
reliability with limited duration). Go first class and get an Antares,
or kick it down a few notches and get the electric powered Silent. You
still have the pylon and prop, but those are not the unreliable parts of
the self-launching system. And they are quiet.

--
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change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

In article ,
Eric Greenwell wrote:
Mark James Boyd wrote:

A mini-turbine glider would really be a true self-launcher. It
would not be a multi-launcher or sustainer (due to the fuel
consumption). But fuel is quite easily available, and it isn't
much of a stretch to pick airports with fuel as landouts,
or have an FBO hold on to a can of it for you, or have crew bring
you some. A mini-turbine would be very similar
to an aerotow in capabilities and limitations...

Using a motorglider the way you mention is quite useful and
practical and flexible. On the other hand, that technique
makes me consider those applications as just flying an
airplane that has a very high glide ratio and turning off
the engine sometimes.

Bad analogy, because the ratio of soaring to engine time is still very
high - even my longest retrieve still had 3 hours of soaring and only 40
minutes of engine for about 140 return. No one else flew from our
airport, because the bad air had already arrived when I left.

I'd be very willing to forego that
option to avoid icky pylons and props and unreliability.

You don't have to wait for turbines to get this ability (simplicity and
reliability with limited duration). Go first class and get an Antares,
or kick it down a few notches and get the electric powered Silent. You
still have the pylon and prop, but those are not the unreliable parts of
the self-launching system. And they are quiet.

--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA


One small issue with the electric idea is that the batteries are heavy
and can't cheaply be ejected as ballast. And the useful time of running
the engine is directly related to weight. Reliability is certainly
improved over those pesky two-strokes, and perhaps the prop vs.
hot turbine exhaust on the tail is a satisfying tradeoff.

However, a quiet engine would likely be VASTLY preferred by glider
pilots due to the much lower noise vs. turbine. Additionally, the
idea that one could design such an engine so that one could thermal
and then descend with the engine out, using the engine to RECHARGE the
batteries, seems possible. Electric cars, for braking, can use
a generator instead of dissipating all the energy as friction.
The concept in gliders could possibly be similar. I don't know
the details of such a design, but the possibility is interesting
in theory.

Mr. VanGrunsven sent me an e-mail asking about these turbines, and
I referred him to AMT and Accurate Automation Corporation. In any
case, I really hope I get to see, and perhaps fly, all
different kinds of self-launchers (pylon, retract prop, electric,
and turbine). I find EAA and gliders and the creative minds
of tinkerers makes soaring a very fun sport. After all, we just do
this for FUN, right?

P.S. Holly Katherine Boyd, born Dec 30, 2003, 7lbs. 7oz.
Momma and baby are perfectly healthy and want to go SOARING!!

Mark James Boyd wrote:
P.S. Holly Katherine Boyd, born Dec 30, 2003, 7lbs. 7oz.
Momma and baby are perfectly healthy and want to go SOARING!!

Congratulations, Mark! Not much flying for you for a while, if my
experience as the happy father of a 5 year old applies...

Marc

In article ,
Marc Ramsey wrote:
Mark James Boyd wrote:
P.S. Holly Katherine Boyd, born Dec 30, 2003, 7lbs. 7oz.
Momma and baby are perfectly healthy and want to go SOARING!!

Congratulations, Mark! Not much flying for you for a while, if my
experience as the happy father of a 5 year old applies...

Marc

Thanks to all well-wishers. My wife has relatives near
several gliderports, so I'm hoping to sneak in excuses
to visit...

on 1/4/04 12:13 "Mark James Boyd" as in
3ff865df$1@darkstar posted the following:


After all, we just do
this for FUN, right?

P.S. Holly Katherine Boyd, born Dec 30, 2003, 7lbs. 7oz.
Momma and baby are perfectly healthy and want to go SOARING!!

Congratulations!


--
Jack

"Warum einfach machen wenn man es so schön komplizieren kann?"