To expand on the earlier statement I made that flaps essentially 'quit
working' if a glider so-equipped is landed 'too fast,' even a short-span
(55') HP-14 with original (long) length flaps exhibits the behavior.
Understand we're talking a rather fine point here when considering HP
gliders (which generally have LOTS of flap compared to other flapped gliders
with which I'm reasonably familiar...Zuni's, Concept 70's, Nuggets and
PIK-20A/B's).

At the time I sold my '14 I felt I could easily put it into any field an
experienced 1-26 pilot would go for...and some unavailable to 1-26's
(because of the HP's steeper approach capability). May not have been
correct, but that's the confidence I felt in the bird. (Prior to the HP, I
flew a 1-26; it, too, is a ship that helps pilots build confidence in the
basics.)

I'd encourage any driver of a flapped ship to experiment at the home field
to convince himself to what degree his or her ship exhibits the 'quits
working' behavior. Once you're comfortable and consistent making
_full-flap_ approaches, roundouts and touchdowns under reasonable
conditions, start adding a speed increment coming downhill. Use the same
aiming point as for your normal landings. For example, if you're consistent
at 45 knots, pick up the next landing to 50 knots, then to 55, etc. Do the
flare carrying the extra speed, so's to end up nose-down a foot or so off
the deck, waiting for the speed to bleed off. Not 'too far' above your
normal approach speed, you'll find you're amazed at how much farther the
bird will float before 'drag overcomes downwash.'

The weaker the flaps, the more noticeable the effect.

The only reason I mentioned the effect is because discovering it on a
short-field outlanding made in dicey conditions that may encourage the pilot
to carry some extra speed (e.g. gusty winds, conditions conducive to wind
shear, etc.) is likely to set off some more ill-considered 'flaps are spawn
of the devil' stories!

For the record, I never experienced an indicated airspeed change due to
windshear in my HP-14 when making full flap approaches. I _have_
experienced them in my Zuni making full flap approaches. I'm reasonably
satisfied the difference lies in the flaps...the HP's were draggier,
necessitating a considerably nose-lower attitude. Get nose down enough, and
horizontal wind shear speed deltas in essence decouple from the glider's
airspeed. Imagine being able to do a vertical approach - your touchdown
spot will change due to horizontal windshear, but not your indicated
airspeed.

Since not all windspeed changes occur in the horizontal plane, a prudent
pilot may opt to carry extra speed despite powerful flaps, but the way to
shoehorn into a small field under those conditions is to begin bleeding the
extra speed off earlier/higher in the flare.

Regards,
Bob W.


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