Fixing Roll

[BlackbusheFlyer]

I agree with the principal that adverse yaw/roll should exist within the sim however I can not help but feel it is applied in too linear a fashion. Test flight on Spitfire at 67% throttle, 2200 RPM no trim, you need a boot full of right rudder to counteract yaw and about 10-20 degree of left aileron to balance the aircraft. Apply rudder trim to remove skid and still require a 10-20 degree aileron deflection to counter roll.

This makes sense at high RPM/power settings but not at cruise power. No real life aircraft I have flown is rigged where you need substantial cross control to maintain straight and level at cruise.

Personally I think the torque effect curve needs looking at.

There are written accounts of spitfires trimmed to fly hands off (Wingleader by J.E.Johnson for one). In CoD at the moment that is just not possible, you can not remove the need to hold aileron no matter what power setting and to me that is not quite right. Something like a pitts special which is extremely twitchy and a real split arsed aircraft will cruise along quite happily with the lightest touches.

[bongodriver]

Originally Posted by BlackbusheFlyer

I agree with the principal that adverse yaw/roll should exist within the sim however I can not help but feel it is applied in too linear a fashion. Test flight on Spitfire at 67% throttle, 2200 RPM no trim, you need a boot full of right rudder to counteract yaw and about 10-20 degree of left aileron to balance the aircraft. Apply rudder trim to remove skid and still require a 10-20 degree aileron deflection to counter roll.

This makes sense at high RPM/power settings but not at cruise power. No real life aircraft I have flown is rigged where you need substantial cross control to maintain straight and level at cruise.

Personally I think the torque effect curve needs looking at.

There are written accounts of spitfires trimmed to fly hands off (Wingleader by J.E.Johnson for one). In CoD at the moment that is just not possible, you can not remove the need to hold aileron no matter what power setting and to me that is not quite right.

Neither of us have time on a spitfire, and I'm not sure what time you have on vintage, but the stearman I fly has a 'huge' prop with a 220hp radial driving it, it is fairly torque'y, I think a 1,000hp merlin driving a 10' prop even at cruise will produce lots of torque and even more gyroscopic effect, without aileron trim I don't see how an aircraft can be hands off and in balance.

[BlackbusheFlyer]

Originally Posted by bongodriver

Neither of us have time on a spitfire, and I'm not sure what time you have on vintage, but the stearman I fly has a 'huge' prop with a 220hp radial driving it, it is fairly torque'y, I think a 1,000hp merlin driving a 10' prop even at cruise will produce lots of torque and even more gyroscopic effect, without aileron trim I don't see how an aircraft can be hands off and in balance.

Well I stand to be corrected, however it just doesn't feel right to me. The rigger should adjust manual trims to counter for the cruise. My current CAA examiner has flown the spitfires for the BoB memorial flight, I mean to ask his opinion on this.

[BlackbusheFlyer]

Just to add a heavyweight to the argument:

"The Spitfire looked good and was good. But my first reaction was that it was bad for handling on the ground; its long straight nose, uptilted when the tail wheel was on the ground; its long straight nose, uptilted when the tail wheel was on the ground, made taxing difficult since it was not easy to see ahead. It was necessary to to swing from side to side to look in front. The view at take-off was restricted in the same way until you were travelling fast enough to lift the tail; only then could you see over the nose.

Once accustomed to these minor inconveniences, they were no longer apparent, and once in the air, you felt in the first few minutes that here was the aeroplane par excellence. The controls were light, positive and synchronized; in fact, the aeroplane of one's dreams. It was stable; it flew hands and feet off; yet you could move it quickly and effortlessly into any attitude. You brought it in to land at 75 mph and touched down at 60-65 mph. Its maximum speed was 367 mph. You thus had a wide speed range which has not been equalled before or since.

It had eight machine guns of .303 calibre each, mounted four in each wing. The guns were spaced one close to the fuselage, two mid-wing, one further out. The eight guns were normally synchronized to 250 yards. In other words the four in each wing were sighted so that the bullets from all eight converged at that distance, in front of the Spitfire. Experienced fighter pilots used to close the pattern to 200 yards. The successful pilots succeeded because they did not open fire until they were close to the target."

Douglas Bader in 1940 on the Spitfire Mk1.

[bongodriver]

It always has been described as a 'pilots dream' in flight, the gound handling aspect is not an unfamiliar scenario for alot of taildraggers, again I put the stearman into it with its very high ground angle and large round front end it is impossible to see ahead until the nose is lowered, the spitfire pilots I have spoken to would describe something similar to your extract....but hands off might be a bit of interpretation, I consider the Stearman to be more hands off than the Tiger Moth but it is only a relative term.

[Voyager]

On prop torque, I recall descriptions of the the F4F Wildcat having enough torque that if you ran up the engine all to full power on the ground, that the tire on the down side would be pressed flat.

I seem to recall that being in the book "Ace", the one about the Hellcat night fighter ace pilot. I believe that one also involves the story about going inverted for the first time to discover that the ground crew had left a wrench in the plane.

Even jets have torque effects. The F-16's engine has enough momentum that if it suddenly stops, it will kick the plane over about a quarter roll before the fly-by-wire compensates for it. The early GE engines when installed in the F-16 had a tendency to vent all of their oil overboard. It's not a feature, just a bug.

[BlackbusheFlyer]

Alex Henshaw wrote:

"After a thorough pre-flight check I would take off and, once at circuit height, I would trim the aircraft and try to get her to fly straight and level with hands off the stick ..."

Yes I agree it is relative (I too have flown more than 1 moth) however it would be stretching the term a bit far carrying quite as much deflection as present within CoD. I wonder if DB or Henshaw would use those same terms after flying the CoD spitfire (which after-all is what we aiming for right, that those same highly emotive comments could come from the CoD spit as the real thing).

I am not suggesting that the principal implementation is wrong, just that the curve needs some further examination. Possibly more benign in the middle and more extreme at the end, for example... stalling the spit then shoving in full power would (I can very well imagine) torque roll like a beast.

[bongodriver]

I should have mentioned I don't seem to be struggling with the same problem on my hardware, in actual fact I have been cruising the spit almost hands off, so I will grant that I may be making an assumption and some of you guys may be experiencing a problem, seems there are a few 'bugs' that affect some more than others.