Bonus Jet glider demo weekend

I think a turbo prop would be ideal for smoothness and better fuel
efficiency. I don't guess a small light turbine powered prop has been
developed.

On Apr 25, 9:50*pm, Mark Jardini wrote:
I think a turbo prop would be ideal for smoothness and better fuel
efficiency. I don't guess a small light turbine powered prop has been
developed.

The model airplane guys have developed working turboprop engines
though possibly not at the scale we need.

The little turbojets have many advantages starting with their
simplicity, small size and low residual weight after the fuel is
gone. Adding a prop adds complexity and weight of a gearbox while
reducing the "self-retrieval" speed.

On Apr 25, 8:50*pm, Mark Jardini wrote:
I think a turbo prop would be ideal for smoothness and better fuel
efficiency. I don't guess a small light turbine powered prop has been
developed.

Ah I don't thinks so. The gear reduction, drive and prop retract and/
or folding mechanisms and need for a belt or high mounted jet engine
are all likely horrible complications. The sorts of current
motorglider complications we want to get away from.

BTW there are small jet turboptops in use for models etc. (e.g.
http://www.jetcatusa.com/spt5.html).

Darryl

On 4/25/2011 8:50 PM, Mark Jardini wrote:
I think a turbo prop would be ideal for smoothness and better fuel
efficiency. I don't guess a small light turbine powered prop has been
developed.

The company that makes the turbine used on the BonusJet makes a
turboprop version.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

Is there any danger to the vertical stabilizer from the exhaust heat?
I asked this of the owner of the Silent jet and they said that the
skin temperatures were "within tolerances". Hmmmm.

I just worry that given enough time the heat may affect the structure
of the tail (glass? carbon fiber?) with the potential of loosing the
tail. While I might be able to live with loosing a rudder, loosing
the elevator is a whole other matter. If this was a conventional
tail, rather than a T tail, there would be an additional safety
factor. Are there other aircraft with a configuration like this? All
I can think of are private, commercial or military jets in which
engine heat is definately not directed against an airframe member.

I believe that safety dictates adding a metal heat shield formed to
the shape of the vertical stab. This would include a thin air gap
(glued on non-metallic blocks) so no heat would transfer. Pretty
simple to create and install. This wouldn't decrease the performance
of the glider to any great degree (or any at all?) as the vertical fin
is a non-lifting surface (might affect rudder performance?) - - but
would greatly increase my comfort level.

I can hear those infamous last words now, "Don't worry, we've never
had a problem." ;-)

John "My $0.02 of Safety" DeRosa