I don't think that does a very good job of explaining it.

Basically the way it works is that a spinning mass will act like a gyroscope. There are two primary characteristics of a gyro:

1) Rigidity in space: the gyro has a tendency to resist forces applied to it, it is stable on the axis it spins. This is the principle behind which a spinning top stays upright, and the incorporation of gyroscopes in flight instrument have resulted in instruments like the artificial horizon which by maintaining rigidity in space allow for flight solely by reference to the instruments.

(http://upload.wikimedia.org/wikipedia/commons/d/d5/Gyroscope_operation.gif)

2) Precession: when a force is applied perpendicular to a spinning rotor the rotor will resist the force where it is applied and the force will manifest 90 degrees later in the direction the rotor is spinning.

(http://upload.wikimedia.org/wikipedia/commons/thumb/3/35/Gyroscope_wheel-text.png/800px-Gyroscope_wheel-text.png)

(http://upload.wikimedia.org/wikipedia/commons/2/26/Gyroscope_wheel_animation.gif)

If you have have spun a bicycle tire that was not mounted to the bike you have no doubt noticed the somewhat peculiar nature of a gyroscope:

Gyroscope precession (http://www.youtube.com/watch?v=IEwAry0GARw#normal)

MIT Physics Demo -- Bicycle Wheel Gyroscope (http://www.youtube.com/watch?v=8H98BgRzpOM#noexternalembed-normal)


To put that into flight dynamics terms the propeller/propeller + rotary engine will act like the gyro, and any pitch or yaw changes of the aircraft can be thought of forces applied to the disk of the rotor. For example, pitching up as in a loop can be thought of like pulling the propeller disk at the 12 oclock position (applied force), assuming the propeller rotates clockwise (as viewed by the pilot) the force will manifest 90 degrees later, at the 3 oclock position as if the pull on the prop disk happened there. In other words the airplane will yaw to the right you pull the nose up for the loop, it will yaw the nose to the left when you push forward on the stick, it will cause the nose to rise when you apply left rudder pressure, and the nose will be driven down when the pilot applies right rudder.The more abruptly the pitch or yaw deviation, the more obvious this gyroscopic precession will be. Also, the greater the RPM/diameter/mass of the gyro, the greater the resultant gyroscopic action.

In a plane like the DrI, Sopwith Camel and the N17/N28 to a lesser extent a pilot trying to make a level turn will roll the airplane and then apply aft elevator inputs, as we've already discussed this means the nose of the airplane will be driven to the right and the pilot will need to compensate with a left rudder application. This happens in both left or right turns since the elevator input is what is driving the gyroscopic effects and that is common to conventional turns in either direction. This is different than a pilot of a modern aircraft who would generally need to apply rudder in the direction of the turn to prevent a slipping turn (uncoordinated flight). This same dynamic will manifest when applying abrupt rudder commands, pitch inputs will need to be made in order to compensate for gyro effects.


Here's some greater details:

http://www.history.com/encyclopedia.do?vendorId=FWNE.fw..gy117200.a#FWNE.fw..gy117200.a (http://www.history.com/encyclopedia.do?vendorId=FWNE.fw..gy117200.a#FWNE.fw..gy117200.a)

Great!!  and it's illustrated :)

I belive it might be appropriate at this point to point out that the issue over at Neoqb with Gyroscopic Precession is not about it's existance or about Petrovich understanding the principle;

The issue is about the Quantity of Gyroscopic Presession present in the latest public release...

At least that's how I understand it....

S~

Gunny

Quite right gunny. . .but I also know that a community that doesn't understand these things will not relate well to them if they encounter them in the sim and don't understand the nature of them. In other sims I've found many people complain about realistic additions to the flight physics of a sim and even call it a bug. Gyroscopics are strange to many people, as are things like adverse yaw etc.

Yes - As always the instructional material and presentation is priceless to me :)

This is why I've started and will continue to start numerous threads concerning sound and sound engineering in simulation.

I feel sometimes that if we don't step in and summarize occasionally - folks might leave a thread without current context...

Thanks..

S~

Gunny

Select DrI
Take off
Turn Left

Yeah, there it is....

1. Roll DrI left
2. watch gyro precession pull nose up over the horizon - more elevator you put in the quicker it climbs to stall

Better

1. Roll DrI left, gradually applying left rudder to counteract the precession and finally to hold nose on horizon for turn..... decrease rudder deflection to product left hand sprial......

S!

Gunny