Flaperons

recall one similar to what you've described Warren, where somebody (some
stupid maintenance guy) ejected into the hangar overhead.


Is this the one where the retracted basketball net kept him from falling back
to the deck?
CV45, off coast of Korea. F9F. I was there but did not see it.
Warren

Nils Rostedt wrote...

Speaking of gliders, I wonder if any gliders have
an arrangement whereby both ailerons can be moved
in unison to a really high negative (up) angle,
in effect acting as spoilers or speedbrakes...

What you describe sounds like "crow" mixing,
where the flaps go down and the ailerons (both)
reflex up. It's still used in RC gliders, and
given that there are several powered airplanes
that use it or something similar I'd bet that
there are full-size gliders that use it as well.
There's also trailing edge reflex, where flaps
and ailerons all move *slightly* trailing edge up,
but not a lot, and that's for drag reduction in
cruise, not drag increase for approach. Some
full-size gliders use this as well.

Dave 'poor man's DLC' Hyde

"Dave Hyde" wrote in message
...
Nils Rostedt wrote...

Speaking of gliders, I wonder if any gliders have
an arrangement whereby both ailerons can be moved
in unison to a really high negative (up) angle,
in effect acting as spoilers or speedbrakes...

What you describe sounds like "crow" mixing,
where the flaps go down and the ailerons (both)
reflex up. It's still used in RC gliders, and
given that there are several powered airplanes
that use it or something similar I'd bet that
there are full-size gliders that use it as well.
There's also trailing edge reflex, where flaps
and ailerons all move *slightly* trailing edge up,
but not a lot, and that's for drag reduction in
cruise, not drag increase for approach. Some
full-size gliders use this as well.

Dave 'poor man's DLC' Hyde






The most successful high-drag device is a Shempp-Hirth trailing edge dive
brake. The half span flaps go to 80 degrees down and a surface of equal
span and width rotates up from the upper wing surface on the same hinge line
as the flaps. This results in a surface twice the chord of the flaps at
right angles to the airflow. The effect is dramatic. Several pilots have
had police meet them on the ground after landing to investigate the 'crash'.

The view from the cockpit is scary at first. The nose is so far down that
it looks like a 'lawn dart' maneuver. Precision spot landings are very easy
when you get the hang of it. Just aim the nose at the touch down spot. If
you see you are long, just push the nose further down - the airspeed won't
increase. The flare has to be timed right but the feel is very slow and
"floaty" with a soft touchdown and short roll. You get the feeling that you
could land on a 'postage stamp'.

Bill Daniels

"Bill Daniels" wrote in message
news:GILld.337003$wV.41042@attbi_s54...

The most successful high-drag device is a Shempp-Hirth trailing edge dive
brake. The half span flaps go to 80 degrees down and a surface of equal
span and width rotates up from the upper wing surface on the same hinge
line
as the flaps. This results in a surface twice the chord of the flaps at
right angles to the airflow. The effect is dramatic. Several pilots have
had police meet them on the ground after landing to investigate the
'crash'.

The view from the cockpit is scary at first. The nose is so far down that
it looks like a 'lawn dart' maneuver. Precision spot landings are very
easy
when you get the hang of it. Just aim the nose at the touch down spot.
If
you see you are long, just push the nose further down - the airspeed won't
increase. The flare has to be timed right but the feel is very slow and
"floaty" with a soft touchdown and short roll. You get the feeling that
you
could land on a 'postage stamp'.

Bill Daniels


Though off the subject. The approach described above is similar to that
experienced in sailplanes that depend solely on large span flaps. (SGS 1-35,
PIK-20B and the Schreder HP/RS/RHJ series.) For example, a Schreder HP-14's
40:1 glide ratio is decreased to 2:1 when the flaps are lowered to 90
degrees. This gives an approach angle of 30 degrees which requires the nose
to be 45 degrees below the horizon. It takes some getting use to; however,
once mastered it makes short field landings "a piece of cake".

See:
http://www.soaridaho.com/Schreder/HP...NG_THE_14.html
http://www.soaridaho.com/Schreder/St..._HP_flight.htm
http://www.soaridaho.com/Schreder/Large-span_flaps.html
(Other stories can be found at:
http://www.soaridaho.com/Schreder/Sc...e_Stories.html)

Wayne
http://www.soaridaho.com/Schreder

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.....

--
Marc J. Zeitlin
http://marc.zeitlin.home.comcast.net/
http://www.cozybuilders.org/
Copyright (c) 2004

"Marc J. Zeitlin" wrote in message
news:PiPld.610968$8_6.562540@attbi_s04...
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.....


The stall speed of a HP-14 with a 90 degree flap setting is only 30 mph.
The approach is flown at 55 mph (the best L/D speed with 0 degree flap
setting) to provide the ability to take of a little flap while raising the
nose if you are tracking short of the desired touch down point. Lowering
the flaps changes the effective angle of incidence of the wing with
relationship to the fuselage. In the case of the HP-14 this is about 15
degrees.

The attitude of the HP-14 sitting on the runway is the approximate attitude
at which it stalls with a 90 degree flap setting. As you fly the approach
at 55 with full flap you look landing aim point is well above the nose of
the glider. In fact it is almost up to the canopy bow.

(Pictures of HP-14 large span flaps:
http://www.soaridaho.com/Schreder/HP...41/N8041_1.jpg more links
http://www.soaridaho.com/Schreder/HP...-14_Links.html)

Respectfully,
Wayne
http://www.soaridaho.com/Schreder

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."