Posted: 2/21/2011 22:25:08
I have always been an avid follower of burt rutan's designs combined a strong love composite aircraft. I find it only natural for me to dream of new ways to push the bounds with composite aircraft design. Today my question what would happen if you combined almost sailplane fuselage with glider wings but trimmed them slightly in length to reduce some drag since it would be a powered aircraft. Then put all this on a very clean and low tri cycle configuration. Everything of course being made from composite material. My design goal would be an efficient aircraft with a reasonable cruise speed 110 - 140 range and capable of higher flight due to the lifting abilities of the wing.
Posted: 2/21/2011 22:59:30
Actually it would look very similar to an aircraft called the electra flyer x my plan would be to put a gas burner on it instead maybe a turbo charged corvair think that would perform nicely in the 10,000 to 12,000 foot range.
Posted: 2/22/2011 11:29:15
You'd have a Diamond Katana.
But keep thinking that way. With electric aircraft in the spotlight and with electric batteries not yet competitive with gasoline, electric aircraft will need to eke-out every ounce of airframe efficiency to make up the difference.
And what's more efficient that a sailplane? They don't even need motors, electric or otherwise.
Posted: 2/22/2011 12:30:39
Another example would be the Europa XS. The standard wings are removable and can be replaced with a set of sailplane wings. Cruises in the 130-150 kt range at ~4 gph with a Rotax 9xx series engine. see http://www.europa-aircraft.co.uk/ Yup, you guessed it, I built one.
Blue skies & tailwinds,
Little Toot Sport Biplane
Posted: 2/22/2011 12:35:20
True, however as you know a da-20 is not a home built aircraft. Nor is it as aerodynamically clean as a glider in the fuselage department. My idea would essentially be a chopped up AS28 glider bring the wings down to a more manageable 44ft and place a tear drop cockpit on or slightly aft of wing centerline to help offset the extra weight of the engine. And the perfect engine would be a turbo charged diesel all though on the heavy side of things. This would look very similar to modern high performance gliders much more so then a DA20 same concept though.
Posted: 2/22/2011 12:37:57
The europa is almost identical to the aircraft i have in mind and it is truly an amazing airplane.
Posted: 2/25/2011 12:57:26
I think you have a great idea, not new, but certainly not explored much either. Check out the airplane that had the distance record before the Voyager. http://www.aviastar.org/air/usa/bede_bd-2.php
The Europa and Diamond are nice but too pricy for my budget. I would like a tandem seat motorglider, maybe along the lines of a Sky Arrow 600. I need to find plans or make my own to build.
Why composite? Jim Bede did OK with the SGS 2-32 platform. I think wood might be a less expensive way to construct.
Posted: 2/26/2011 15:38:07
what Justin describes remindes me alot of several motorglider designs which I've flown, e.g. the RF5 and RF5b a design by Rene Fournier and built by Sportavia Pützer in Germany, the Scheibe SF 28 and SF 32, the Grob 109, the Diamond Super Dimona, Taifun 17E and the very advanced Stemme S10. All these designs combine the high efficiency of a glider-like wing lay-out (large span width, high aspect ratio, high L/D ratio) with a fuselage that is more powered aircraft like. The engine power ranges from 65 HP to 80 HP enabling cruise speeds of up to about 100 kts. You can also fly with the engine off and the prop feathered. The handling characteristics of these airplanes are comfortable and easily manageable for the everage pilot also for flying in thermals.
Posted: 2/26/2011 16:44:38
Do you know of any place to find planse for these aircraft?
Posted: 2/27/2011 04:41:46
I'm not shure if there are plans available for all of these aircraft, since that are all certified designs and all industrially built. If I'm not wrong the only excemption is the RF5 motorglider, which was originally intended for amateur construction in the late 1960s before it was aquired by Sportavia Pützer. Maybe you find something in the net when you check for "Rene Fournier". By the way Fournier also designed a motorglider RF10 which in the 1990s was built in Brasilia under the name Ximango. I remember having seen it on an AERO exhebition are at Friedrichshafen. I f I recall it right the RF10 was rather heavy (at least the Brasilian made) but had a excellent surface quality.