Jet Cat P200 read ad ......

Eric Greenwell wrote in message ...
In article ,
says...
That price Ian gave and trust of 42 lbs. was before the motor was completed.
The ad even says available this fall. Its on Jet Cat USA web page, and its a
old ad. I have been in touch with the dealer and the price is about $3200 bucks
and the Jet Cat P200 now produces 50 lbs of thrust. There are several other
companys that make small Jet turbines, I have seen thrust ratings now at 150
lbs. which would be more than enough for self launch. The fin idea was thought
of, but remember that some of the thrust comes from the sucking action of the
motor. The exhaust is 660 C's. If you mount it like a motorglider engine it
will have to high enough so you don't burn your tail feathers off,

Or mount it on a metal Vee tail glider, like an HP-18.

For sustainer use (in-flight use only), vortex generators mounted on
the engine nacelle might mix enough slipstream air with the exhaust to
provide sufficient cooling.

if it drops
out of the belly, then self lauch could cause fob injestion. Shop around and go
out to a rc field where you can see and talk to the guys who have them.
Overhaul is now at 50 hrs. Thats only for inspection and maybe a bearing. No
big thing. 50 hrs is alot of time....about 600 climbs of 2500 ft.

Even for a self-launcher, that's about 5 years of flying, based on my
experience (200 hours a year, about 50 launches and 10 air restarts a
year).

Mounted on a
retractable pod boom with a arm that extends might be a idea. Food for though.
Tom

Even just fixed on a strut about 12" above the fuselage it would have
little effect on thermalling and speeds up to best L/D +10 knots or
so.

I would think that mounting a couple of small jets at or just behind
the wing/fuselage junction could also serve to remove some of the low
speed turbulence in that area. Also, if the engine had a tight
cowling around it then perhaps some water could be sprayed or drizzled
onto the outside of the engine and the resulting steam would mix with
the exhaust to provide some additional thrust. SWB Turbines in
Neenah, WI (SWBTurbines.com)has a Mamba turbojet which puts out 11
Lbs. of thrust. It is only 3.5 inches in diameter and would fit
nicely at the wing junction interface. SWB also has 45, 60 and a
100Lb thrust engine.

In article ,
says...

I would think that mounting a couple of small jets at or just behind
the wing/fuselage junction could also serve to remove some of the low
speed turbulence in that area. Also, if the engine had a tight
cowling around it then perhaps some water could be sprayed or drizzled
onto the outside of the engine and the resulting steam would mix with
the exhaust to provide some additional thrust. SWB Turbines in
Neenah, WI (SWBTurbines.com)has a Mamba turbojet which puts out 11
Lbs. of thrust. It is only 3.5 inches in diameter and would fit
nicely at the wing junction interface. SWB also has 45, 60 and a
100Lb thrust engine.

Perhaps a simple, straight forward way to test the concept is to
remove the engine from a current self-launcher like the PIK 20 E and
replace it with a P200 turbine or similar unit. The mast can already
take the forces, and it wouldn't be necessary actually have it
retractable for the initial tests. A fuel tank is already in the
glider, along with a big battery for starting.

My major concern is the heat of the exhaust, so perhaps the very first
thing to do is measure the air temperature about 12 feet behind one of
these turbines. Maybe it's OK; maybe you find out full power can't be
used on the ground, but enough power to taxi can be used; maybe it's
just too hot, even when mixing with air at 50 knots in climb.

If it worked out, making it retractable would be easy.

I still think someone with a metal vee-tail glider ought to jump on
this idea, and just mount the engine on a short pylon.

--
!Replace DECIMAL.POINT in my e-mail address with just a . to reply
directly

Eric Greenwell
Richland, WA (USA)

Earlier, Eric Greenwell wrote:

I still think someone with a metal vee-tail glider ought to jump on
this idea, and just mount the engine on a short pylon.

Please send one (1) turbojet engine in a stamped, self-addressed envelope...



Bob K.

In article ,
says...
Earlier, Eric Greenwell wrote:

I still think someone with a metal vee-tail glider ought to jump on
this idea, and just mount the engine on a short pylon.

Please send one (1) turbojet engine in a stamped, self-addressed envelope...

I'll send you the stamped, self-addressed envelope if you will put a
HP-18 into it...

Actually, a turbojet self-launcher sounds like a natural business for
someone that knows his way around HP gliders. Not get-rich-quick
business, but a fun one!
--
!Replace DECIMAL.POINT in my e-mail address with just a . to reply
directly

Eric Greenwell
Richland, WA (USA)

Eric Greenwell wrote in message ...

[]
I still think someone with a metal vee-tail glider ought to jump on
this idea, and just mount the engine on a short pylon.

Fiberglass forward fuselage, metal rear fuselage and metal V-tail.
Hmm. Didn't Udo Rumph show us that this formula can still lead to a
very high performance glider (ref. Dick Johnson's recent tests on
Udo's modified HP-18 published in Soaring)?

I think Eric may be onto something...

-Doug

I still think someone with a metal vee-tail glider ought to jump on
this idea, and just mount the engine on a short pylon.

Fiberglass forward fuselage, metal rear fuselage and metal V-tail.
Hmm. Didn't Udo Rumph show us that this formula can still lead to a
very high performance glider (ref. Dick Johnson's recent tests on
Udo's modified HP-18 published in Soaring)?

I think Eric may be onto something...

-Doug

It would be fun the to explore a sustainer jet with the HP18.
A 42 lb thrust jet should do to job, provided it has the same or better
reliability
for starting as a conventional engine.
I would reject a self launching jet version on environmental grounds.

Udo Rumpf

It might get a pit toasty for the wing runner in self-launch mode, but
how about one at each wing tip?

It seems most gliders these days already have some sort of interchangable
tip, so make a new set with a jet built in.

Fuel storage would be the main issue. If you give up the water
ballast option though, there's plenty of room in the wing.

Chris

Slingsby wrote:

I would think that mounting a couple of small jets at or just behind
the wing/fuselage junction could also serve to remove some of the low
speed turbulence in that area. Also, if the engine had a tight
cowling around it then perhaps some water could be sprayed or drizzled
onto the outside of the engine and the resulting steam would mix with
the exhaust to provide some additional thrust. SWB Turbines in
Neenah, WI (SWBTurbines.com)has a Mamba turbojet which puts out 11
Lbs. of thrust. It is only 3.5 inches in diameter and would fit
nicely at the wing junction interface. SWB also has 45, 60 and a
100Lb thrust engine.

Seems to me that a flameout at one tip might be a concern...

How about right at the end of the tailboom? It would require specific
engineering: the glider would have to be designed for it, both to fit
the engine there and from a c.g. point of view - although now that I
think of it, my glider already has tail weights to bring the c.g. aft!
The hot exhaust would be no issue. You'd have to duct inlet air from
the top of the tailboom to avoid ingesting foreign objects. Existing
gliders might be a little tough to retro-fit, but I'd imagine some
clever shops could do it (converting all the certificated gliders to
Experimental in the process, presumably...) As Chris says, you'd put
the fuel in the wings, displacing some (probably not all) of the
water, or put it between the wings in the fuselage. You'd have the
engine so far from the pilot and fuel, the exhaust aft of the
structure, and no complicated swinging arms, bomb bay doors, etc.

The noise in the cockpit would be pretty nasty, though...



Chris Ashburn wrote in message ...
It might get a pit toasty for the wing runner in self-launch mode, but
how about one at each wing tip?

It seems most gliders these days already have some sort of interchangable
tip, so make a new set with a jet built in.

Fuel storage would be the main issue. If you give up the water
ballast option though, there's plenty of room in the wing.

Chris

Slingsby wrote:

I would think that mounting a couple of small jets at or just behind
the wing/fuselage junction could also serve to remove some of the low
speed turbulence in that area. Also, if the engine had a tight
cowling around it then perhaps some water could be sprayed or drizzled
onto the outside of the engine and the resulting steam would mix with
the exhaust to provide some additional thrust. SWB Turbines in
Neenah, WI (SWBTurbines.com)has a Mamba turbojet which puts out 11
Lbs. of thrust. It is only 3.5 inches in diameter and would fit
nicely at the wing junction interface. SWB also has 45, 60 and a
100Lb thrust engine.

asemetrical thrust is one thing near the inboard section of the
wing... but at the outboard end of a high aspect ratio wing! All I can
say is holly crap hold on for one hell of a ride when one engine shuts
down early.

Is my brain fading or did that huge german transport sailplane in WW2
have a jato fail and the with the yaw created by the one rocket cause
it to take out the glider as well as 2 Junkers tow planes at the same
time?

Its a better world with centerline thrust! Mount two engines above the
fusalage and angle them so the thrust is directed to the side of the
tail feathers. The vector would be small and concentrated at the
center of mass if one engine failed just add rudder.

Rocket Science (for people that am smart like I is)



Chris Ashburn wrote in message ...
It might get a pit toasty for the wing runner in self-launch mode, but
how about one at each wing tip?

It seems most gliders these days already have some sort of interchangable
tip, so make a new set with a jet built in.

Fuel storage would be the main issue. If you give up the water
ballast option though, there's plenty of room in the wing.

Chris

Slingsby wrote:

I would think that mounting a couple of small jets at or just behind
the wing/fuselage junction could also serve to remove some of the low
speed turbulence in that area. Also, if the engine had a tight
cowling around it then perhaps some water could be sprayed or drizzled
onto the outside of the engine and the resulting steam would mix with
the exhaust to provide some additional thrust. SWB Turbines in
Neenah, WI (SWBTurbines.com)has a Mamba turbojet which puts out 11
Lbs. of thrust. It is only 3.5 inches in diameter and would fit
nicely at the wing junction interface. SWB also has 45, 60 and a
100Lb thrust engine.