I have been noodling over a motorglider that I would want to own. Basically, I have always been polar to sailplane designs, and I have never liked clubs so self launching and operation from anywhere has been a fascination. Power planes that perform like Cessna 150s are about as boring to me as an airplane can get and they have kept me out of the sport for a long time. Mild aerobatics should be part of sport aviation so for me that should always be a mandatory part of design.
So the questions I had were:
Why can't a motorglider have adequate power, range, baggage carrying capability and cruising speed?
Why can't a motorglider taxi as a normal airplane so it can operate from any airport?
Why can't a motorglider have an adequate engine that can run at high power settings and cruise for long periods of time so it can double as a cross country ship?
Why can't all of this be done without compromising horribly on gliding performance?
I know the answers for most of those things and the Stemme does a good job at a high price with narrow gear and some odd systems and a HUGE wing but with high performance. Most of the other motorglider configurations seriously compromise something to get something else. What I also know is that a modern standard class dedicated sailplane is a marvelously efficient machine in that it can cruise at high speeds at high wing loadings compared to most general aviation aircraft like the C150. With the HP of a C150 and slightly more drag than a modern standard class competition glider you would have something somewhat revolutionary. HP to sustain a standard class sailplane is trivial. HP to sustain high speed cruise is actually fairly small. Water ballast is used to give the wingloading and foster the "g" part of the momentum equation for high speed cruise so if you had fuel there instead of water you could go a long way at that speed.
Other things I would like in an airplane are:
A LARGE and comfortable cockpit with intuitive controls that seems more like a fine sports car than the insides of a 50's science experiment lab. My Audi A6 is the goal to hit there. Great cockpit.
Baggage capacity enough to be useful as a cross country machine.
Large fuel capacity optionally so that you can go cross country sometimes but most times just sport flying around the local airfield.
Approaching 200mph cruise with a low fuel consumption per mile.
Outstanding visibility cruising, landing, taxiing, taking off...
Removable outer wings, drive up on normal trailer, store in garage.
Major crashworthiness with robust roll over protection.
More than adequate climb performance.
Transition from gliding to powered cruise without hassle or dangerous time lags with drag buildup and trim changes. Push button, engine starts, push throttle, go flying power plane. No mixture controls, no breakers to set.... Altitude compensating fuel injected regular old engine technology.
And this is what I came up with. 15 Meter span. Thunder Aviation 4 stroke dry sump (and maybe a turbo... hint). Conventional differential braking taxiing with castering tailwheels, retracts, yadda. Folding pusher prop, blades geared together so they open and close in unison, custom hub with existing stock blades from Warpdrive or equivalent. Integrated aileron and flap mechanism to knock down CL of the profile for high speed cruise. Regular tanks in center section between booms. Aux tanks in removable wings with electric transfer pumps for both filling and fuel transfer (Autoreply gets all credit for that).
I know, looks like all my other designs. Whaddya gonna do?
So the questions I had were:
Why can't a motorglider have adequate power, range, baggage carrying capability and cruising speed?
Why can't a motorglider taxi as a normal airplane so it can operate from any airport?
Why can't a motorglider have an adequate engine that can run at high power settings and cruise for long periods of time so it can double as a cross country ship?
Why can't all of this be done without compromising horribly on gliding performance?
I know the answers for most of those things and the Stemme does a good job at a high price with narrow gear and some odd systems and a HUGE wing but with high performance. Most of the other motorglider configurations seriously compromise something to get something else. What I also know is that a modern standard class dedicated sailplane is a marvelously efficient machine in that it can cruise at high speeds at high wing loadings compared to most general aviation aircraft like the C150. With the HP of a C150 and slightly more drag than a modern standard class competition glider you would have something somewhat revolutionary. HP to sustain a standard class sailplane is trivial. HP to sustain high speed cruise is actually fairly small. Water ballast is used to give the wingloading and foster the "g" part of the momentum equation for high speed cruise so if you had fuel there instead of water you could go a long way at that speed.
Other things I would like in an airplane are:
A LARGE and comfortable cockpit with intuitive controls that seems more like a fine sports car than the insides of a 50's science experiment lab. My Audi A6 is the goal to hit there. Great cockpit.
Baggage capacity enough to be useful as a cross country machine.
Large fuel capacity optionally so that you can go cross country sometimes but most times just sport flying around the local airfield.
Approaching 200mph cruise with a low fuel consumption per mile.
Outstanding visibility cruising, landing, taxiing, taking off...
Removable outer wings, drive up on normal trailer, store in garage.
Major crashworthiness with robust roll over protection.
More than adequate climb performance.
Transition from gliding to powered cruise without hassle or dangerous time lags with drag buildup and trim changes. Push button, engine starts, push throttle, go flying power plane. No mixture controls, no breakers to set.... Altitude compensating fuel injected regular old engine technology.
And this is what I came up with. 15 Meter span. Thunder Aviation 4 stroke dry sump (and maybe a turbo... hint). Conventional differential braking taxiing with castering tailwheels, retracts, yadda. Folding pusher prop, blades geared together so they open and close in unison, custom hub with existing stock blades from Warpdrive or equivalent. Integrated aileron and flap mechanism to knock down CL of the profile for high speed cruise. Regular tanks in center section between booms. Aux tanks in removable wings with electric transfer pumps for both filling and fuel transfer (Autoreply gets all credit for that).
I know, looks like all my other designs. Whaddya gonna do?
