DG Differences...

Greg Arnold wrote:
g l i d e r s t u d wrote:
Marc in a feild landing you would touch down at 60mph?

I would NOT touch down at 60mph (I must have had one of those special
unflapped gliders that stalled less than 60)? I did say low energy and
nose high. Im not a math guy but isnt energy=velocity squared?

Snip

What speed do you land at in order to stop in 130 feet?

For short, obstructed-approach, field-landings, you can't have too much
disposable drag. The shortest non-abbie-normal landing I ever witnessed
was from the cockpit of my HP-14, on an unpaved, alluvial-fan airfield,
in a 5-knot breeze, at 5300' msl. After nailing the approach (easy to
do with high drag) and a tail-first flare, I paced off the main-wheel
roll at 3 fuselage lengths...accomplished w/o nose-dragging braking.

I have no idea what actual touchdown speed was, though the last part of
final was flown at 40 knots indicated (utterly benign conditions, and,
well above indicated stall speed). Point being, lots of drag and lift
can't be beat for steep, slow approaches, and short landing rolls.
Personally, I find high-drag ships much easier to consistently land than
low-drag ones.

Regards,
Bob W.

P.S. Kinetic Energy = 1/2*Mass*(Velocity*Velocity), so touchdown energy
is proportional to velocity squared. Your wheel brake knows only
velocity-squared in energy dissipation terms (though aerodynamic drag is
its friend early-on in the landing roll).