Adverse Yaw

[Duckwing6]

Hyas!
maybe just my oppinion but from my flying experience no powered airplane (especially HIGH powered airplane) has such a strong adverse yaw (e.g. if you roll right the nose swings left and vice versaw) than the AH planes (pretty much all of them).

They feel more like gliders in that respect.. I see the need of alot of rudder for turque and P effects countering on these planes but roll yaw coupling needs to be worked on.

SC-Duckwing6

[funked]

I remember reading that the F4U had a significant adverse yaw.

[Duckwing6]

well as i said maybe Torque, Slipstream, Gyroscopic effects and P-factor when you are slow and/or have a high AOA but not that strong adverse yaw when you make an aileron input during cruise... I mean these things have short and straight wings both not really prone to Dutch roll and adverse yaw phenomena...



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[funked]

Yes, but they don't have much vertical stab area in most cases.

[CombatWombat]

Despite the small vertical tail adverse yaw still shouldn't be a problem.  It's caused by one aileron creating more drag than the other for a moment (or so I believe).  From what I've heard this was only a problem in a few aircraft, most notably the P38L.  

Despite it's large wingspan and wideset ailerons, the standard controls couldnt exert enough force to expose the ailerons into the airflow.  Hence, no (or little) adverse yaw.  The L model with it's hydraulic controls was more prone to yawing.  

As for normal shorter-winged singles, AH seems to over-do the yaw.  In my expierience this is the cause of most of my "nose bouncing".  Once at speed the side of the fusalauge should offer plenty of stability.  

[Duckwing6]

true wombat.. the longer the wingspan the more adverse yaw.
Also Rudder input at high speed should be way more damped.. unless the plane had hydraulic controls the pedals must have been VERY stiff at higher speeds .. given the big maximum deflection angle.

[-lynx-]

Well all planes suffer from adverse yaw - it's caused by the same thing that keeps them in the air   . The pressure on the underside of the wing is higher than the pressure on the upper side (hence lift  ). Therefore an aileron deflected down would create more drag as the pressure on it's surface is higher than that on the other side causing the whole thing.

I'd have thought that later war plane with all hydraulics and stuff should be free of adverse yaw effects? Certainly it shouldn't be THAT noticeable when 7,000-10,000lbs is moving at 300+mph. Same goes for the dreaded nose bounce...

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-lynx-
13 Sqn RAF

[This message has been edited by -lynx- (edited 12-21-1999).]

[funked]

Wombat:  America's Hundred Thousand has handling qualities reports for the US fighters, and there are plenty of mentions of adverse yaw and directional stability problems.

[CombatWombat]

At what airspeed?  The thought of 10,000 lbs moving at 350mph and bobbing back and forth kinda boggles the mind.


>Wombat: America's Hundred Thousand has handling qualities reports for the US fighters, and there are plenty of >mentions of adverse yaw and directional stability problems.

[funked]

I don't remember the airspeed, but I agree that at 350 mph things should be pretty stable.

[Duckwing6]

how about asking -ZOLL- on the F4U he has the firsthand experience on moving an F4U around at 350mph ... i doubt that he's using the rudder too much while manouvering (unless you do a WIDE speed range in your manouvers)

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[flakbait]

No kidding about that adverse yaw. I was driving a 190 around today and every time I moved the ailerons I would slide around like I was on ice. It needs to get fixed.

Flakbait
Admin, Delta 6's Flight School

[BBGunn]

Most all of the basic flight manuals I have come across state plainly that if you roll right you have to use right rudder and if you roll left you have to use left rudder to compensate for aileron induced yaw.  You really cannot just roll the plane and expect a smooth turn.  Even in something as docile as a Cessna 172 you have to use some rudder or the nose will go high on you.  

[Duckwing6]

well i've my share of flying experience in the 172 . and other planes .. but belive me they WILL turn smoothly when you just use the yoke (to make a REALLY nice coordinated turn you'll hardly have too look at the rudde pedals) .. That's why all the Cessna jokeys forget what the rudder's for  
i'm flying gliders a lot too and THERE you need a LOT of rudder but as said that's 17m (56 ft) wingspan to act as a lever for the drag created by the down alieron...

[Swoosh]

Its easy to tell the guys who don't get the "bungee bounce" effect.