"BllFs6" wrote in message
...
Hi Guys

Thanks for the replies Bill and Vee Duber!

Given that gliders are sooo darn efficient fuel wise and that it would
take a
pretty minimal engine for one to self launch (20hp is my WAG for a single
seater).....

More like 50 - 60 HP to get a decent ROC.

why do we not see more airplanes that a cross between a glider and
a conventional plane?

We do, they are called "Touring Motorgliders" and are widely available.
See Grob 109 or the Super Ximango. They use Rotax 912's.


Glider pilots hate engines? Powered pilots want barrel rolls and roaring
engines? Never the twain shall meet?

Aerobatic gliders are very common. Engines make aerobatics less capable
because of the weight and reduced load factors. Silent aerobatics in a
glider are a wonder to behold.

OTOH, Bob Carlson of Albuquerque has an ultralight sailplane with two model
airplane turbojets on it - goes like a scalded cat. We call it the "Dog
Whistle" behind his back. Bob has an airshow act doing aerobatics in it.

Self launch gliders are getting more popular all the time. In Europe, over
half the new gliders sold have self launch capability.


Seems to me if cost and the amount of time airborne are your primary
desire
drivers then a "overpowered" glider would be the ticket...

If you want air time and low cost, go for a pure sailplane. Most of my
buddies are out on 300 mile, 6 hour flights every weekend. 6 hours from a
$20 tow is less than $4 an hour. Pure gliders stay in the air so long they
have to be plumbed for relief tubes.

BTW, I always thought of an X-15 or the Space Shuttle as an overpowered
glider.....

Am I right in the main disadvantage of a powered glider is long take off
rolls
and lack of fancy aerobatics? Other considerations I am missing?

The disadvantage is cost, maintenance and complexity. The number of bells
and whistles in a motorglider darn near equals a twin.


And another question just popped into my head...anyone ever seen a canard
glider?

Yup, Burt Rutan's "Solitare". Probably his worst design which is why you
haven't heard of it. Canards are very inefficient at low speeds and high
AOA - they make lousy gliders.


Bill Daniels