frederick wilson

Thanks Kevin.

Other than the stall info, wing loading is pretty much the same as blade
loading in helicopters. I guess that is why the Blackhawk is so stable in
the rear. The tailrotor produces something like 10% of the total lifting
force for a given gross weight. That is a lot of lift for those little
paddles back there. But they are spinning quiet fast.

Fred

corrie

Wing loading is the weight supported by each square foot of wing. Two
aircraft with the same weight and the same wing area must have the
same wing loading. A light airplane with a small wing can have the
same wing loading as a heavy airplane with a large wing.

Aircraft with low wing loading bounce around more in bumpy air. They
also have lower stall speeds, take-off speeds, and landing speeds.
Disregarding structure, an aircraft with lower wing loading can pull
more g's without stalling than an a/c with high wing loading. The
massive six-prop B-36 bomber of the 1950's had lower wing loading than
contemporary jet fighters, depending on how it was loaded. It could
could often out-turn them, especially at altitude. Very embarrassing
for the jet jockeys.


Corrie

big john

Corrie

----clip----

The massive six-prop B-36 bomber of the 1950's had lower wing loading
than contemporary jet fighters, depending on how it was loaded. It
could could often out-turn them, especially at altitude. Very
embarrassing for the jet jockeys.


How true. At altitude, I many times went into a high speed stall and
'fell out of the sky' while trying to turn with some ex 'fighter jock'
flying a B-36 (


Big John

corrie

And adding insult to injury, not only were they tracking you with
several pair of 20mm cannon during your gyrations, when you finally
departed the area, the aircraft commander probably unstrapped and went
downstairs for a cup of coffee!

todd pattist

This assumes a larger wing on one plane (and presumably
about the same weight for both aircraft). That's possible,
but it's also possible that we're talking about two
identical aircraft (same size wing on both) and one is just
carrying more weight. In that case, the "change in amount
of lift" would be roughly the same for both since the
coefficient of lift changes roughly linearly with AOA.

You'd still get less g-load in the higher wing loaded
aircraft simply because the heavier aircraft accelerates
more slowly when the same amount of lift is applied.


So true :-)

Todd Pattist
(Remove DONTSPAMME from address to email reply.)
___
Make a commitment to learn something from every flight.
Share what you learn.

kevin horton

Agreed. My explanation only covered one case, but the logic and result
(higher wing loading = lower g excursions in turbulence) are valid over a
wide range of scenarios. The premise falls apart a bit if the aircraft
with lower wing loading also has a very low aspect ratio (e.g. 60 deg
delta wing), as the lift curve slope is lower on the lower aspect ratio
wing. Lower lift curve slope = lower increase in lift for the same change
in angle of attack. While the effect of very low aspect ratio on ride
quality in turbulence is technically interesting, it probably isn't
relevant to many homebuilt aircraft.

--
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://go.phpwebhosting.com/~khorton/rv8/