Re: To Steal an F-86

[Dudley Henriques]

"Stephen Harding" > wrote in message
...
> Stephen Harding wrote:
>
> > "Smithsonian Air and Space" has an interesting article describing Soviet
> > attempts to get their hands on an F-86 during the Korean War.
>
> As an addendum, the US of couse badly wanted a MiG-15, and eventually got
> one flown over to it by a defecting NK pilot ($100K bonus for the pilot).
>
> My father flew the MiG to the US via Okinawa I think (by transport
aircraft
> that is). Wish he was around to be quizzed on the details.
>
> A very hush hush operation at the time!
>
>
> SMH
I actually met the pilot of this Mig in a back room meeting one night. His
name was No Kum Suk or something similar if I recall. Nice guy too! I
remember how stupid it all was trying to keep him a secret when everybody in
sight was interviewing him. In fact, I seem to recall talk in the fighter
community at the time about him being sent to the University of Delaware for
some promised education. I believe he actually did end up there. I lost
track of him after this period. I do know that Yeager, Boyd, and Collins
went to Okinawa to fly the damn thing.

Dudley Henriques
International Fighter Pilots Fellowship
Commercial Pilot/CFI
Retired

[Peter Stickney]

In article >,
Stephen Harding > writes:

<Snip - a precis of the Kremlin's hare-brained scheme to capture a
Sabre in Korea Note that Peplayev was much less charitable than I in
his characterization of the plan. >

> One of the most useful knowledge gains was with the radar controlled gunsight
> used on the F-86. Very accurate and helping tilt the balance of light
> weaponry of the F-86 (6 .50 MG) against the MiG (37 and 23mm cannon).
>
> The Soviets developed a reciever that listened specifically for the wavelength
> of the gunsight radar, thus giving the Soviet pilot some warning of
> approaching USAF Sabers. It was prone to give false readings, but was an
> overall invaluable feature. The life of its developer was probably saved
> by its success since he had the misfortune of being "politically incorrect"
> enough to be "denounced" at a time when it meant the Gulag or worse.
>
> This electronic device is standard part of any modern fighter aircraft
> indicating "radar lock" from targeting AAA/missiles.

And AN/APG radar was certainly a "find" I don't think that a
dedicated receiver was the result, though. The APG=30 was basically
as sinple as a Police Speed Radar (Well, pulsed instrad of CW Doppler,
but not much more complicated) It was very low power, adn didn't scan,
radiating in an 18 degree fized fan. Range was limited to 'bout
3,000 yds. Even granting that a radar receiver would be able tp pick
up the radar's emissions at longer range, by the time that you'd pick
up the APG-30, teh Sabres would be in sight.

One thing they did profit from was examining teh boosted control
system and (IIRC, it was an F-86E that they got) the flying tail.
This didn't help the MiG-15 or -17 very much, but it made all the
difference in the MiG-19.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[Stuart Chapman]

> One of the most useful knowledge gains was with the radar controlled
gunsight
> used on the F-86. Very accurate and helping tilt the balance of light
> weaponry of the F-86 (6 .50 MG) against the MiG (37 and 23mm cannon).

In use, did this radar provide a lead point in the HUD at which to aim??

Stupot

[John Carrier]

> In use, did this radar provide a lead point in the HUD at which to aim??

Not a HUD, merely a gunsight. Lead computing gunsights adjust for bullet
trajectory based on gravity and aircraft load factor (G). The pilot could
adjust the sight for target range and (sometimes, usually?) wingspan of the
target aircraft (the better to estimate range by). Once engaged, you had a
sight that provided a correct lead solution for a particular range
(typically 800-1000 feet).

With radar input, the range setting is based on actual target range vice a
fixed input, thereby eliminating a variable in what is typically a highly
dynamic environment.

R / John

[Stephen Harding]

Peter Stickney wrote:

> One thing they did profit from was examining teh boosted control
> system and (IIRC, it was an F-86E that they got) the flying tail.
> This didn't help the MiG-15 or -17 very much, but it made all the
> difference in the MiG-19.

They first got an F86-A and later an E.


SMH

[William Donzelli]

(Peter Stickney) wrote in message >...

> And AN/APG radar was certainly a "find" I don't think that a
> dedicated receiver was the result, though. The APG=30 was basically
> as sinple as a Police Speed Radar (Well, pulsed instrad of CW Doppler,
> but not much more complicated) It was very low power, adn didn't scan,
> radiating in an 18 degree fized fan. Range was limited to 'bout
> 3,000 yds.

The range computer in the AN/APG-30 is pretty slick - not overly
complex, all electronic, and in a pretty small package (actually in
the same box as the power supply).

Uhh...anyone have any spare AN/APG-30 antenna units they would part
with?

--
William Donzelli

[Peter Stickney]

In article >,
Stephen Harding > writes:
> Peter Stickney wrote:
>
>> One thing they did profit from was examining teh boosted control
>> system and (IIRC, it was an F-86E that they got) the flying tail.
>> This didn't help the MiG-15 or -17 very much, but it made all the
>> difference in the MiG-19.
>
> They first got an F86-A and later an E.

Ah, O.K.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[Peter Stickney]

In article >,
"John Carrier" > writes:
>> In use, did this radar provide a lead point in the HUD at which to aim??
>
> Not a HUD, merely a gunsight. Lead computing gunsights adjust for bullet
> trajectory based on gravity and aircraft load factor (G). The pilot could
> adjust the sight for target range and (sometimes, usually?) wingspan of the
> target aircraft (the better to estimate range by). Once engaged, you had a
> sight that provided a correct lead solution for a particular range
> (typically 800-1000 feet).
>
> With radar input, the range setting is based on actual target range vice a
> fixed input, thereby eliminating a variable in what is typically a highly
> dynamic environment.

If I may amplify a bit, here - The sight itself wasn't all that much
different than any other gyro gunsight. The Gyro sights measured teh
precession of a pair of gyroscopes in the sight to measure the
azimuth/elevation rates when the pilot (or gunner, if it was a turret
installation) tracked the target, cross-referenced that with bullet
Time of Flight, which is affected mostly by range, but also by the
bullet's drag (deceleration after leaving the barrel), and a couple of
other factors (Jump, which is a fudge for the gun moving when the
bullet's fired) and gravity frop (again, propotional to time of
flight). The sight, using the range, jump, and bullet drop factors to
adjust the tension of springs hooked to the gyroscopes, would move the
piipper (Aiming Mark) to the spot calculated to be the correct lead
necessary to hit the target. As you can see, it's really imortant to
have the proper range (and range rate, in more sophisticated sights).
In WW 2, when the sights first came out, this was done using
stadiametric techniques. You dialled in the opponent's wingspan on
the sight, and, using a twist grip like a motorcycle throttle
(Actually on the throttle for fighters, or one of the sight grips for
bombers) adjusted a circular range reference reticle to fit the
wingspan of the target's image. Of course, if the target wasn't quite
head on, you had to fudge it a bit, to get it right. This means,
though, that your pilot or gunner is a busy guy, working the stick &
throttle to smoothly track a jinking target, or a target making a
Curve-of-Pursuit pass, where the range and elevation/azimuth rates are
changing all the time, and trying to be as smooth as possible while
tracking the target so that the sight settles down. The biggest
errors that occurred with the sights were range measurement and
tracking. In the late 1940s, teh Air Force and Navy decided that it
would be a good thing to use a small, non-scanning radar that only
tracked range to feed accurate range measurements to the sight. This
was the genisis of the AN/APG-5 and AN/APG-30 that ended up in all the
U.S. swept-wing jets that didn't have a bigger air-intercept radar.
Thae AN/APG-30 was a small pulse set, that swept a range gate
(it would only look for an echo for a small part of the time that a
pulse was going out & bouncing back, that correponded to a particular
range) out through its max range of 6,000', and would lock onto and
track the range of the nearest target in its field of view. (Well,
it's a little more complicated than that - there was a button on the
pilot's stick that would tell the radar to ignore the target it was
tracking and move out to the next one). This, whne it worked,
provided fairly smooth, accurate range measurements to the signt, and
allowed it to compute a better lead. With teh high closing speeds
that jet fighters had, and the large lead angles needed to track
crossing targets, it was a very useful item indeed.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[Peter Stickney]

In article >,
(William Donzelli) writes:
> Stephen Harding > wrote in message >...
>
>> The Soviets developed a reciever that listened specifically for the wavelength
>> of the gunsight radar, thus giving the Soviet pilot some warning of
>> approaching USAF Sabers. It was prone to give false readings, but was an
>> overall invaluable feature.
>
> This is interesting, but I must wonder why the Soviets were not clued
> in sooner. The radars were X band units, not some oddball frequency. I
> would think their countermeasures guys would have received the
> emissions almost as soon as the radars were deployed.

Becasue fighter airplanes, especially Soviet-built fighter airplanes,
didn't carry ELINT gear. Panoramic receivers back then ere heavy and
complicated beasts that required very specially trained operators.

They'd also have to be looking at those frequencies, as well. Soviet
stuff at that time tended to be on the lower end of the mifrowave
scale, with most sets being in the VHF & UHF bands, and a few AAA Fire
Control systems being as high as S band. Ther actually was quite a
lot of controversy about the wisdom of fitting S-band jammers (APT-6?)
to the FEAF and SAC B-29s that were bombing the DPRK at night. The
bomber crews wanted the protection, but the PLanning and Strategy
people were worried about losing some over North Korea, and providing
the Soviets with examples of our latest jamming technology and
high-power S-Band transmitting tubes.


--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[[email protected]]

(Peter Stickney) wrote:

>
>Radiop Research, in Waterbury CT, has complete units listed in the
>Thomas Register. And all sort of other neat toys. I'm saving up for
>the MD-5 system (B-52 tail turret, including tboth th eradars and the
>turret) myself.

But not the twenties Pete?...you disappoints me... :)

(picturing your turret mounted on your pickup truck with a B & W
just slashing in 10 feet behind you with lights and sirens
blaring and these twin 20's swinging around and depressing to
point right into his windscreen !!!... HooWee!...)
--

-Gord.

[Blair Maynard]

On Fri, 04 Jul 2003 15:44:19 GMT, "Gord Beaman" )
wrote:

(Peter Stickney) wrote:
>
>>
>>Radiop Research, in Waterbury CT, has complete units listed in the
>>Thomas Register. And all sort of other neat toys. I'm saving up for
>>the MD-5 system (B-52 tail turret, including tboth th eradars and the
>>turret) myself.
>
>But not the twenties Pete?...you disappoints me... :)
>
>(picturing your turret mounted on your pickup truck with a B & W
>just slashing in 10 feet behind you with lights and sirens
>blaring and these twin 20's swinging around and depressing to
>point right into his windscreen !!!... HooWee!...)

Might explain why his local police preordered the new "stealth" model
police cruisers.

[Peter Stickney]

In article >,
Blair Maynard > writes:
> On Fri, 04 Jul 2003 15:44:19 GMT, "Gord Beaman" )
> wrote:
>
(Peter Stickney) wrote:
>>
>>>
>>>Radiop Research, in Waterbury CT, has complete units listed in the
>>>Thomas Register. And all sort of other neat toys. I'm saving up for
>>>the MD-5 system (B-52 tail turret, including tboth th eradars and the
>>>turret) myself.
>>
>>But not the twenties Pete?...you disappoints me... :)

You just wouldn't believe the paperwork involved. A .50 cal can be
done, but anything over that, and you enter Destructive Device
territory. Think of it as teh difference between a Secret and a Top
Secret Clearance.

>>
>>(picturing your turret mounted on your pickup truck with a B & W
>>just slashing in 10 feet behind you with lights and sirens
>>blaring and these twin 20's swinging around and depressing to
>>point right into his windscreen !!!... HooWee!...)

Nah, we're all friendly folks down here. The big car chases only
happen in the movies. For that matter, they never gave me any flak
about the tanks - or when we registered an M20 Armored Scout Vehicle
as a 1943 Ford Convertable.

I woldn't mind one of those 1&1/2 ton Chevys with the Martin turret
that they used for gunnery training, though. with a lead-computing
gunsight and a pair of autofeeding 12-Gauges I might actually hit one
of those danged ducks. (Spent years shivering in the swamps - the only
duck I get I hit with the truck on the way home. He was executing a
missed approach while overgrossed & couldn't climb out of the way)

> Might explain why his local police preordered the new "stealth" model
> police cruisers.

Actually, I had the Chief LEO come by a couple of years back wanting
me to broker a deal for some Armo[u]red Cars. (Money to use, and
nifty toys, basically). I was able to talk him out of it, though by
pointing out that he'd never be able to afford the supporting infantry
he'd need to go with them. They were much better off spending teh
dough on communications gear.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[Bill Silvey]

"Peter Stickney" > wrote in message

> In article >,
> Blair Maynard > writes:
>> On Fri, 04 Jul 2003 15:44:19 GMT, "Gord Beaman" )
>> wrote:
>>
>>> (Peter Stickney) wrote:
>>>
>>>>
>>>> Radiop Research, in Waterbury CT, has complete units listed in the
>>>> Thomas Register. And all sort of other neat toys. I'm saving up
>>>> for the MD-5 system (B-52 tail turret, including tboth th eradars
>>>> and the turret) myself.
>>>
>>> But not the twenties Pete?...you disappoints me... :)
>
> You just wouldn't believe the paperwork involved. A .50 cal can be
> done, but anything over that, and you enter Destructive Device
> territory. Think of it as teh difference between a Secret and a Top
> Secret Clearance.
>
>>>
>>> (picturing your turret mounted on your pickup truck with a B & W
>>> just slashing in 10 feet behind you with lights and sirens
>>> blaring and these twin 20's swinging around and depressing to
>>> point right into his windscreen !!!... HooWee!...)
>
> Nah, we're all friendly folks down here. The big car chases only
> happen in the movies. For that matter, they never gave me any flak
> about the tanks - or when we registered an M20 Armored Scout Vehicle
> as a 1943 Ford Convertable.

You could get a flatbed deuce-and-a-half and do a Guntruck-workup ala the US
Army in Vietnam.

Some of those SOB's had 7.62 miniguns!

--
http://www.delversdungeon.dragonsfoot.org
Remove the X's in my email address to respond.
"Damn you Silvey, and your endless fortunes." - Stephen Weir
I hate furries.

[William Donzelli]

(Peter Stickney) wrote in message >...

> Becasue fighter airplanes, especially Soviet-built fighter airplanes,
> didn't carry ELINT gear. Panoramic receivers back then ere heavy and
> complicated beasts that required very specially trained operators.

Certainly the fighters did not have the equipment, but I would think
that the Soviets would have flown ELINT missions, or perhaps a ground
station picking up the emissions.

> They'd also have to be looking at those frequencies, as well. Soviet
> stuff at that time tended to be on the lower end of the mifrowave
> scale, with most sets being in the VHF & UHF bands, and a few AAA Fire
> Control systems being as high as S band.

The Soviets knew we liked X band for aircraft radars - it was
available in small quantities on the surplus market at the time.

--
William Donzelli

[Merlin Dorfman]

According to something I saw on the History Channel yesterday,
the F-86 had an all-flying tail (though they used another term)
first developed for the X-1 (called XS-1). It enabled pitch control
in the transonic region, without which supersonic flight could not
have been achieved, and it made the F-86 a much better dogfighting
aircraft at transonic speeds.
Did the Soviets learn about the all-flying tail from the
captured F-86, and put it on their later fighters>
------------------------------------------
Stephen Harding ) wrote:
: "Smithsonian Air and Space" has an interesting article describing Soviet
: attempts to get their hands on an F-86 during the Korean War.

: A first plan was developed to use specially trained pilots of MiG-15s to
: actually box in a candidate F-86 and force him down at a Communist base.

: The Russian CO of the Soviet AF unit actually fighting in Korea (USAF pilots
: had come to suspect they were fighting Russians rather than NKs or Chinese
: but there was still nothing official known about their presence), thought
: the plan idiocy, and this was proven with the gradual shoot down of many
: in the unit attempting to corral a Saber.

: But an F-86A eventually went down and was hauled off, barely making an
: escape from an attacking B-26. The aircraft was tested and quite a few
: features found their way into MiG-15 and 17.

: One of the most useful knowledge gains was with the radar controlled gunsight
: used on the F-86. Very accurate and helping tilt the balance of light
: weaponry of the F-86 (6 .50 MG) against the MiG (37 and 23mm cannon).

: The Soviets developed a reciever that listened specifically for the wavelength
: of the gunsight radar, thus giving the Soviet pilot some warning of
: approaching USAF Sabers. It was prone to give false readings, but was an
: overall invaluable feature. The life of its developer was probably saved
: by its success since he had the misfortune of being "politically incorrect"
: enough to be "denounced" at a time when it meant the Gulag or worse.

: This electronic device is standard part of any modern fighter aircraft
: indicating "radar lock" from targeting AAA/missiles.


: SMH

[Peter Stickney]

In article >,
Guy Alcala > writes:
> Emmanuel Gustin wrote:
>
>> "Merlin Dorfman" > wrote in message
>> ...
>>
>> > Did the Soviets learn about the all-flying tail from the
>> > captured F-86, and put it on their later fighters>
>>
>> The F-86A did not have the flying tail, this feature was
>> introduced by the F-86E. This model entered combat in
>> Korea in September 1951.
>>
>> The first Soviet fighter with the flying tail appears to
>> have been the SM-9/2 prototype of the MiG-19, which
>> was built in 1954.
>>
>> So it is quite likely that the Soviets were aware of the use
>> of a slab tailplane on the F-86E when they designed the
>> SM-9/2. On the other hand, NASA's adoption of the
>> 'flying tail' appears to have been inspired by British
>> data.
>
> There's a common misconception here. The "all-flying tail" on the
> F-86E and F wasn't a slab, it was a movable stabilizer with
> separate (but linked) elevator, as developed for the XS-1 (and
> credited by Yeager with allowing the a/c to be controllable through
> the Mach). The slab came in on the F-100, IIRR. From what I
> recall, there'd come a Mach number when the shock wave from
> compressibility would make the elevator ineffective (usually
> leading to tuck under), but the stabilizer itself would then be
> forward of the shock and retain its effectiveness. So the
> stabilizer was made movable (i.e. trimmable like a Buff, but
> directly connected to the joystick instead of just the trim switch)
> and linked to the elevator around a center pivot. The two surfaces
> were geared to move in a certain relationship to each other. I
> don't know the specific details (whether it was based on IMN or
> just a pure mechanical relationship). Hopefully Mary, Pete or
> someone else can fill in the details.

F-86D/Ls and Hs had a one-piece slab.
The reason for th all-moving tails (dangit, no chalkboard again! Assume a
chalkboard, and a lot of Fighter-Pilot hand talking)
Think of the stabilizer/elevator combination as a wing (Wich, after
all, it is) At subsonic speeds, deflecting the elevator affects the
airflow over the entire surface, so that the entire are of the
stabilizer is used to control pitch. As the flow over the stabilizer
gets transonic, and the shockwaves form, elevator deflection begins t
only effect the flow over the elevators themselves, greatly reducing
effectiveness. The solution is to move the entire stab (stabilator),
which lets the entire surface develop whatever lift needs to be
created to counterbalance the wing. (It's early yat - I've only had 1
cuppa Coffee) Why doesn't every airplane use this? (The Wright
Brothers did) The problem is that once the stabilizer had to get
above a certain small size, it's danged hard to move manually, no
matter how much you balance it. It took the advent of powered
controls, (The electric screw jack on the XS-1, or the hydraulics on
the F-86E) to make it practical.

You can certainly fly a transonic or supersonic airplane without using
a slab, but what happens is that your pitch authority (Ability to
raise or lower the nose) decreases, and, depending on the
configuration, teh airplane may not be able to be trimmed at all.
(The pitchup of the F-84s, for example.)

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[Merlin Dorfman]

Peter Stickney ) wrote:

....

: You can certainly fly a transonic or supersonic airplane without using
: a slab, but what happens is that your pitch authority (Ability to
: raise or lower the nose) decreases, and, depending on the
: configuration, teh airplane may not be able to be trimmed at all.
: (The pitchup of the F-84s, for example.)

Is this the "control reversal" at transonic speed mentioned in
the British film, "Breaking the Sound Barrier?" (I know that
opinions vary as to whether or not control reversal is real.)

[[email protected]]

"ian maclure" > wrote:

>In article >, "Merlin Dorfman"
> wrote:
>
>> Peter Stickney ) wrote:
>>
>> ...
>>
>> : You can certainly fly a transonic or supersonic airplane without using
>> : a slab, but what happens is that your pitch authority (Ability to :
>> raise or lower the nose) decreases, and, depending on the :
>> configuration, teh airplane may not be able to be trimmed at all. : (The
>> pitchup of the F-84s, for example.)
>>
>> Is this the "control reversal" at transonic speed mentioned in
>> the British film, "Breaking the Sound Barrier?" (I know that opinions
>> vary as to whether or not control reversal is real.)
>
> Control reversal is a real aeroelastic effect.
> Nothing mythical about it.
> Basically moving the control surface bends the airfoil which overpowers
> whatever effect the movibale control surface was supposed to provide.
>
> IBM
>
But why wouldn't this merely reduce any intended effect?...IOW
you want 'that wing' up, you put 'that aileron' down but the
slipstream is so strong that the aileron moves only half as far
as you commanded and the wing flexes the opposite way to make up
the difference?...I think it has to do with the shock 'spike'
which moves erratically with small changes in transonic speeds
and this provides the actual reversal.
--

-Gord.

[Peter Stickney]

In article >,
Merlin Dorfman > writes:
> Peter Stickney ) wrote:
>
> ...
>
>: You can certainly fly a transonic or supersonic airplane without using
>: a slab, but what happens is that your pitch authority (Ability to
>: raise or lower the nose) decreases, and, depending on the
>: configuration, teh airplane may not be able to be trimmed at all.
>: (The pitchup of the F-84s, for example.)
>
> Is this the "control reversal" at transonic speed mentioned in
> the British film, "Breaking the Sound Barrier?" (I know that
> opinions vary as to whether or not control reversal is real.)

Well, the movie's a movie, and then, well, there's reality.
In the early days of flight into the transonic reagion, airplanes
would display all manner of behavior. Some would pitch down, (Meteor)
SOme would pitch up (F-84) Some would pitch down & then pitch up
(Canberra, IIRC), some would porpoise divergently, eventually risking
breaking up (Vampire), and soem would just keep right on going with
the pilot more passenger than director. (Venom). I suppose it would be
possible for an airplane to pitch up and then pitch down, but usually
the pitchup was so severe that it bled off a lot of speed, and bent
the airplane.
This was due to the various shifts of the Center of Moment of the
airfoil as shockwaves began to form and move along the wing and tail
surfaces. What gets felt in the cockpit is the change in trim force
as this happens, and the perceived feel of what's going on. For
ecample, you're hauling back in the stick, with nothing happening, and
then the airplane pitches up to the extent that holding the stick in
place feels like you're pushing it. Elevators don't work backwards,
or anything like that. It was possible to get situations where
aileron deflection at high speeds would bend the wing in the opposite
direction, reducing and eventually reversing roll control. B-47s were
quite prone to this, which led to the redline limit of 425 kts IAS.
F-86s were somewhat subject to it, and some of the thinner winged
transonic fighters like the FJ-4 Fury and F3H Demon could, it hey had
a tendency to roll a bit be "fixed" by slamming the stick hard over at
high IAS, bending the wings into rig. (Sort of like warping the
wingtip of a balsa glider to make it fly straight)
This concern about bending the wings is what led to the inboard
ailerons of the F-100 and F-8 Crusader.
Nowadays, (Post 1955 or so), we seem to have a handle on it, and
passing through the transonic range is a bit dull. All you notice is
a bit of change in the trim feel on some airplanes, the ASI jumps, and
the fuel goes away fast.

If you get a chance, go check out the NACA Technical
Reports Server, for teh period between 1943 and 1953. There's a lot
of stuff in there on the transonic behavior of a lot of airplanes,
ranging from dive tests of a glider P-51 to the pitchup tendencies of
various swept-wing jets. Most of it is, well, technical, (saves
changing the name), but the abstracts can be rather clear.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[Michael Williamson]

wrote:

>> Control reversal is a real aeroelastic effect.
>> Nothing mythical about it.
>> Basically moving the control surface bends the airfoil which overpowers
>> whatever effect the movibale control surface was supposed to provide.
>>
>> IBM
>>
>
> But why wouldn't this merely reduce any intended effect?...IOW
> you want 'that wing' up, you put 'that aileron' down but the
> slipstream is so strong that the aileron moves only half as far
> as you commanded and the wing flexes the opposite way to make up
> the difference?
>
> -Gord.


Depending upon the relative strength of the wing and its size,
it may or may not cause reversal (control reversal doesn't
happen with EVERY airfoil, and in some designs happens well
below the transonic range). But if the wing is weak enough,
then the aileron acts as a trim tab on an elevator or aileron,
and the overall effect is to reverse the results of the control
input.

Mike