roll comes from torque and gyroscopic procession

engine making the prop spin clockwise will force the engine block anti-clockwise

:rolleyes:

I know, you are 11 posts to late ;) see

http://forum.1cpublishing.eu/showpos...2&postcount=10

you failed to mention the engine though, which is the major part. ;) [ the propeller is nothing more than basically (though not exactly) another wing going 'round in circles... an airscrew ]
and which is what makes a motor vehicle lurch to the side when the (predominantly N/S) engine is revved up suddenly

regardless....

I thought a larger influence was that the airflow from the propeller is not straight, but spirals rearwards across the fuselage and wings. It strikes the stabilizer from one side constantly for example, pushing the tail in that direction. I don't know if these forces are contrary or reinforce the actual torque effect from the propeller.

its like this:

A helicopter had to have the tail rotor put on it for what reason?

that's right... to prevent the main rotor and the main body (housing the engine) from spinning in opposite direction.

double main rotor 'copters spin in the opposite direction: why?







and there is no prop on the ever popular car anology, when the engine is revved hard causing lurch.

piston drives the cranshaft which turns the prop. the piston moves down bwcause the explosion, which causes the movement because it forces the piston to move down using the block/ head as the base. the engine block is mounted securely to the vehicle, etc, etc, etc

no but there is a large 'flywheel' so it's not completely invalid.

for the spitfire it's like this....


torque: prop rotates clockwise, aircraft rotates anti-clockwise, has the smallest effect of all 3.

propwash: causes the aircraft to yaw left with increased power...right rudder required to counter

gyroscopic precession: pitch up causes yaw right, pitch down causes yaw left, this seems to be the strongest effect, if you are trimmed with a pitch up bias the aircraft will want to roll right.

all these forces will change according to power setting and control inputs, only rudder and elevator can be trimmed, therefore there will tend to be a requirement to keep hands on stick to counter all the secondary roll forces induced by yaw, and this is largely felt as a roll right, even a fixed aileron 'tab' will only be effective at a set speed range.

flywheel is part of the crankshaft though and has no air drag as such


"torque: prop rotates clockwise, aircraft rotates anti-clockwise"

crankshaft rotates (on which the prop is attached) clockwise, inside the engine block. the crankshaft rotates because of the pistons driving the shaft, the pitons push against the engine block, because the pistons/ cranshaft is the movable object when the engine block is securely mounted on a firm surface. when there is no firm mount, the engine block floats... so the crankshaft/ pistons pushes against the engine block which in turn is moved in the opposite direction

prop wash is applicable until airspeed is greater

torque is not really an effect purely of air resistance, it is more to do with inertia, the flywheel is a heavy mass (just like a prop) and causes resistance to the power of the engine, that energy needs to find its way somewhere, inevitably it will cause the whole engine block to rotate in the opposite direction, I know.. I've seen it, an engine on a static test bench being revved will lurch in the opposite direction of crankshaft rotation, essentially we are in agreement on this effect but with slightly differing perceptions on its cause.

propwash is a factor as soon as the power is applied and is harder to control at low speeds because the aerodynamic controls havent got a 'bite' on the airflow

basic law of motion... "For every action there is an equal and opposite reaction"





http://www.aerospaceweb.org/question...s/q0015a.shtml

might help/ might not

Me personally no, I studied enough of that on my ATPL theory, so I am fully up to speed on all these effects.