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

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

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


'unless your eyes are cheated by some spell'

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


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


Tom De Moor