So its under elevatored then.

Al

"Marske Flying Wings" wrote in message
...
No this is where you are quite wrong! There is pleanty of up elevator on
the
trailing edge of the main wing.... the air going over the top is
separating
due to the high angle of attack and this makes the elevator ineffective,
so
the nose lowers slightly and the glider picks up airspeed and it resumes
normal flight.


"spektr" wrote in message
...


Bravo.
So you are flying a glider with insufficient up elevator to cause a
stall
equipped
with an airspeed indicator that doesn't register well on the low end of
the
spectrum.
All wings stall when their critical angle of attack is exceeded. In its
most benign
form a stall will be recognnized as a slight vertical oscillation
without
a
discernable
break. If you had more elevator authority, it would get into this
flight
mode. Its inability
to do so indicates a lack of elevator authority at slow speed.

Your airspeed indicator reading zero means you are flying at a speed
less
than the minimum
required to move the needle. You are probablu using a run of the mill
ASI
for airplanes.
Nothing wrong with that, it just means you are slower than the gauge can
indicate. You
might consider an ASI for helicopters, they are much more sensitive at
the
lower end
of the spectrum and will probably give you a better indication of whats
going on.
If you want to make your glider even more efficient, replace the ASI
with
a
Mach Meter.
Then you can get 30 something to one l/d with an indicated airspeed of
ZERO.

OBTW, Its impossible to fly with an airspeed of zero, lift requires air
movement over the wing
on any conventional fixed wing airplane. You by definition still have
airspeed if you are flying.

Scott

Scott did you miss the part in my posting where I said this airspeed was
calibrated by itself and then while in the glider at differing airspeeds
from 40 mph to 80 mph. using a GPS method posted on our website. It is
also
helicopter airspeed. Now I do think that at about 20 mph the airpspeed
goes
to zero... but again I did not test it in the aircraft for this slow a
flight. What did confuse me was the low sink rate... but I could have been
in rising air... and next time I will check my GPS groundspeed. But I have
this on video and will post it for all to see.

I was actually quite surprised myself and do not really know what to think
of it. By the way this aircraft has a 3.6 lbs per sq ft wing loading and I
easily fly at 90 to 100 mph. and I have videos of that too. Again that
part
of the spectrum has not been calibrated but it is interesting to see how
well it flies at that speed. I will push for 130 mph in the sping when I
have redone the canopy and fuselage.

-mat