On 8/11/2011 8:01 AM, Tony wrote:
The biggest downside to flaps is that they are hard to train for,
since there are few two-seaters that have them. And too many gliders
that do have them (I'm looking at you, SGS 1-35), don't have enough of
them, so it's too easy to float down the runway. Flaps that go to only
60 degrees aren't enough; it takes at least 85 to reliably kill the
float and get onto the ground with authority.

Bob I've got to send you a picture of the NG-1 with full flaps out. In
fact I need to shoot some landings in it sometime and get some photos
of it from the ground. That thing is impressive! I'm pretty sure the
handle is limited to about 60 degrees or so but that is more than
enough flap. In fact it takes about all the strength in my left arm
to get that much flap at a typical 60 mph approach speed. The flaps
are the same as a BG-12/16 and run from the root to the aileron. On
the few full flap approaches i've done SeeYou has shown an L/D of
somewhere around 5.

Using crude distance measuring methodology (altimeter for vertical/paced-off
distance for horizontal), I eventually concluded the HP-14 I flew, achieved a
full-flap final-approach L/D, at 45 knots indicated, of somewhere between 3:1
and 1:1, the latter number being easily approached in even the lightest
headwind. I was simply curious, and didn't really care what the 'real' number
was, once it became (more or less instantly [happy memory!]) apparent that the
risk of undershooting in such an immensely 'approach capable' ship was
non-existent.

Nonetheless, despite the immense drag of that particular ship's
fully-deflected flaps, it remained possible for Joe Pilot to 'throw away'
some/all of the flaps' short-field landing capability by flaring 'too fast,'
in which case - as others have noted the possibility of doing - you *would*
float long and far in ground effect. I don't mean to suggest that every
flare/landing need/ought to be a low-energy affair, but if you're flying a
large-deflection-landing-flapped ship and routinely taking a longer distance
to flare, touchdown and roll-out than your buddies in otherwise similar
spoilered ships, you might want to continue learning how to safely extract the
unused landing performance that *does* reside in your ship.

Regards,
Bob W.