Gyroscopic Precession in the WW1 rotary engine observed by a pilot

[Mano]

A WW1 Sopwith Pup with a rotary engine.



 It turns at a different rate going left vs going right.

 

[FLS]

It's easy to see gyroscopic precession in Aces High. Just pitch up or down and you'll see the resultant yaw. When you are banked for a turn the yaw from gyroscopic precession is what raises the nose in a right turn and drops the nose in a left turn. This happens in all the single engine fighters in AH but it's most noticeable with the massive torque of the rotary engine aircraft.

Gyroscopic precession doesn't occur in a steady state turn, it's only evident when you rotate the pitch axis so it's a momentary reaction to pitch or yaw input. When you yaw the resultant precession will pitch you up or down slightly. If you are correcting your aim with rudder pedals you might see the nose bounce.

[Mano]

From the pilots point of view there would be precession to the right as the rotary engine turned in a counter clockwise direction. The engine weighed about 850 lbs. Rotary engines of this era usually turned at approximately 1200 rpms. The pilot had to blip the engine to land because there was no way to throttle the fuel. Rotary engines were really difficult to land. A strong crosswind would make landing almost impossible.

 

[FLS]

You misunderstand Gyroscopic Precession. It's not a constant turning force, it's a reaction to a change in orientation. The "d" in the diagram is delta for change. The amount you change one axis affects the change in the other axis.

When you change pitch GP reacts with yaw, when you change yaw GP reacts with pitch.  Precession to the right would only result while pitching up. Pitching down would result in precession to the left. Level sustained turns are relatively steady in pitch so GP is not a factor, vertical turns are not, this is why loops are so much fun with the rotaries.

There is no way the Camel can have a higher sustained turn rate due to GP.  Sustained turn rate is simply thrust, lift, and drag.

It's true that if you are slow in a rotary engine fighter like the Camel a 270 degree descending turn can be faster than a 90 degree climbing turn.
But, if you start slow enough in any fighter the climbing turn will be slower than a descending turn. With a rotary engine like the Camel or Dr1, in a slow climbing turn, you can lose enough stability that you rotate on the yaw axis, reducing your lift enough to drop you straight down. So it's clear why pilots would avoid a right turn. It's a better turn left than right, but it's not higher sustained turn rate.

[nrshida]

I reliable use(d) gyroscopic precession as part of my Aces High ACM to outmanoeuvre better (conventional) turning opponents. The effect is indeed momentary but it doesn't matter when the angular change is so high / rapid.

Testament to AH's flight modelling.