In article PiPld.610968$8_6.562540@attbi_s04,
"Marc J. Zeitlin" wrote:

Wayne Paul wrote:

..... For example, a Schreder HP-14's
40:1 glide ratio is decreased to 2:1 when the flaps are lowered to 90
degrees.

Wow! That's an amazing change.

...This gives an approach angle of 30 degrees which requires the nose
to be 45 degrees below the horizon.

I think you've got this a little backwards - if the approach angle is 30
degrees, the nose can't be BELOW that - you'd have a negative angle of
attack. I think that the nose would be somewhere in the 20 degree down
range, to provide a positive AOA of somewhere around 10 degrees. 20
degrees nose down is VERY down, however - it would certainly LOOK like
you're pointing straight down.....

You're forgetting the effect of lowering the flaps on the actual as
opposed to nominal AOA of the wings.

Ask yourself how much you'd have to lower the nose after lowering the
flaps in order to (for instance) stay at the zero lift AOA relative to
the fuselage...

--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard."