More on the electric verses turbojet

[cdubya]

The more I read the more intrigued I become. Certainly if a turbojet can be
fitted to a hang glider successfully
http://www.users.zetnet.co.uk/flylight/doodlebug/news.htm
then one can be fitted to a sailplane. After reading a lot on the subject
I believe that a 100 or 150 lb thrust motor would be sufficient. Testing
could be done with the larger motor and then the throttle limited once
performance figures are taken and thrust in different configurations
calculated. Microjet engineering (a UK company) makes the APS 150
http://www.microjeteng.com/ which should do the trick.

I was also thinking electric but so far the electric motor companies I have
contacted are not interested. Probably once they hear the word airplane
they run for cover.

[BD5ER]

>I was also thinking electric but so far the electric motor companies I have
>contacted are not interested. Probably once they hear the word airplane
>they run for cover.

Tell them your developing a quiet airboat for biologist to observe endangered
nocturnal swamp critters. <G>

[TomnKeyLargo]

The Jet Cat P200 develops 50 lbs. of thrust. Its price is about $3250 I
believe. On a modern 15 meter ship it should be able to be used as a substainer
engine and be able to give you about 400 fpm climb rates. It burns 23 ozs of
fuel per minute at full throttle and comes with a ECM for start. Carring about
3 gals of fuel should give you four 2500 ft climbs Weights about 5 pds. Tom

[tango4]

$4795 from JetCats website and only 42lbs thrust.

The size of these things might lend them to being installed in the fin. No
heavy and complicated extension mechanism or bomb bay doors.

Ian


"TomnKeyLargo" > wrote in message
...
> The Jet Cat P200 develops 50 lbs. of thrust. Its price is about $3250 I
> believe. On a modern 15 meter ship it should be able to be used as a
substainer
> engine and be able to give you about 400 fpm climb rates. It burns 23 ozs
of
> fuel per minute at full throttle and comes with a ECM for start. Carring
about
> 3 gals of fuel should give you four 2500 ft climbs Weights about 5 pds.
Tom

[Vaughn]

"tango4" > wrote in message
...
> $4795 from JetCats website and only 42lbs thrust.
>
> The size of these things might lend them to being installed in the fin. No
> heavy and complicated extension mechanism or bomb bay doors.
>
> Ian

TBO? I looked at the site mentioned in a previous post and there were
no TBO specifications given. They did mention that one of their prototypes
had 150 cycles. This does not sound too impressive to me.

At least they are self-starting now, a couple years ago they were still
using leaf blowers.

Vaughn

[Martin Gregorie]

On Mon, 15 Sep 2003 05:28:04 +0000 (UTC), "tango4"
> wrote:

>$4795 from JetCats website and only 42lbs thrust.
>
>The size of these things might lend them to being installed in the fin. No
>heavy and complicated extension mechanism or bomb bay doors.
>
I keep wondering what the drag penalty would be for a fixed
installation, possibly a nacelle on a short pylon with pop-down
intake and exhaust fairings.

I like your fin mount idea, but it would probably need to be designed
in to the glider. OTOH a fixed non-fin installation could be
retro-fitted.


--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

[Martin Gregorie]

On Mon, 15 Sep 2003 05:47:37 -0700, "cdubya" >
wrote:

>None !!!! Ok, maybe a little bit of drag from the intakes. I am thinking
>of mounting it at the rear of a Bowlus Baby Albatross Pod. Seams to me this
>glider is perfect for such a propulsion system since it was done already
>with a prop on The Nelson BB-1. Other pod type designs also lend themselves
>to bury this motor in the rear of the pod with little or no drag penalty.
>Got any areonautical engineers out there in the Denver area that are
>interested in helping?
>
That does sound neat. NACA ducts would add a nice touch with brass
rims to match the polished ply.

I was visualising a backpack with the pylon just long enough to avoid
cooking nearby plastic provided the fin is far enough away for normal
mixing to have cooled the exhaust to below harmful temperatures.

<asbestos suit="on">Your idea should work for a certain Polish World
Class glider too - PW-5J anybody? </asbestos>


--
martin@ : Martin Gregorie
gregorie : Harlow, UK
demon :
co : Zappa fan & glider pilot
uk :

[cdubya]

None !!!! Ok, maybe a little bit of drag from the intakes. I am thinking
of mounting it at the rear of a Bowlus Baby Albatross Pod. Seams to me this
glider is perfect for such a propulsion system since it was done already
with a prop on The Nelson BB-1. Other pod type designs also lend themselves
to bury this motor in the rear of the pod with little or no drag penalty.
Got any areonautical engineers out there in the Denver area that are
interested in helping?

Craig

Martin Gregorie > wrote in message
...
> On Mon, 15 Sep 2003 05:28:04 +0000 (UTC), "tango4"
> > wrote:
>
> >$4795 from JetCats website and only 42lbs thrust.
> >
> >The size of these things might lend them to being installed in the fin.
No
> >heavy and complicated extension mechanism or bomb bay doors.
> >
> I keep wondering what the drag penalty would be for a fixed
> installation, possibly a nacelle on a short pylon with pop-down
> intake and exhaust fairings.
>
> I like your fin mount idea, but it would probably need to be designed
> in to the glider. OTOH a fixed non-fin installation could be
> retro-fitted.
>
>
> --
> martin@ : Martin Gregorie
> gregorie : Harlow, UK
> demon :
> co : Zappa fan & glider pilot
> uk :
>

[Robert Ehrlich]

Martin Gregorie wrote:
>
> On Mon, 15 Sep 2003 05:47:37 -0700, "cdubya" >
> wrote:
>
> >None !!!! Ok, maybe a little bit of drag from the intakes. I am thinking
> >of mounting it at the rear of a Bowlus Baby Albatross Pod. Seams to me this
> >glider is perfect for such a propulsion system since it was done already
> >with a prop on The Nelson BB-1. Other pod type designs also lend themselves
> >to bury this motor in the rear of the pod with little or no drag penalty.
> >Got any areonautical engineers out there in the Denver area that are
> >interested in helping?
> >
> That does sound neat. NACA ducts would add a nice touch with brass
> rims to match the polished ply.
>
> I was visualising a backpack with the pylon just long enough to avoid
> cooking nearby plastic provided the fin is far enough away for normal
> mixing to have cooled the exhaust to below harmful temperatures.
>

I think for a sustainer only, a nice place for a glider with a retractable
gear would be to have twin engines on both sides of the wheel. The retracting
mechanism is already there, but the space for the wheel and the weel doors
should probably be enlarged. And if no engine starts, the landing gear is already
extended for an emergency landing.