In article ,
Tom De Moor wrote:

In article ,
says...


Sustained flight as an aircraft =/= sustained flight as an ornithopter

Why? Why would the definition of "sustained flight" change depending on
the type of craft?



Because the subject is not sustained flight but sustained flight by an
ORNITHOPTER

So why does that change the definition of "sustained flight"?

Try an answer that is not begging the question this time.


The Wright Flyer is not an ornithopter but an airplane/glider.

The Flapper (jet powered or propellor pushed) was claimed to maintain
flight / propulsion by the sole use of flapping wings.

There was neither a jet nor a propellor involved.


http://en.wikipedia.org/wiki/UTIAS_Ornithopter_No.1

Right. Where's the jet or the propeller?


http://www.youtube.com/watch?v=a-qS7oN-3tA

Again, where?



'unless your eyes are cheated by some spell'

Sorry, but it's not there.


It is not certain that it achieved that because it is quite likely that
the lift originated from the small wing combined with the flapping wing
wether the big wing was flapping or not. So it is not certain that the
flapping did contribute to lift generation.

There was no other source of thrust involved.


See above

I did see. Moreover, I looked. You should try it.



Otherwise building an ornithopter would be quite ease: take a glider and
when in flight open the canopy and flap your arms. The glider won't fall
(immédiately) out the sky but I suspect that the armflapping will add
nothing but drag.

That won't meet the definition of "sustained flight" even if you don't
flap, because a glider cannot maintain both altitude and airspeed
simultaneously.


In fact the first claims for ornithopter were following this method by
iirc the same German engineer who develloped the Messcherschmidt Comet.
He added clapping paddles to a glider.

I'm sorry, but you're veering into weird, here...


http://www.ornithopter.org/a.schmid.shtml

Yup. "Sustained flight" requires constant altitude and airspeed. The
Comet didn't meet the second criterion.

--
Alan Baker
Vancouver, British Columbia
http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg