Can someone walk me through the propeller effects on stability?
1) I know there's a major destabilizing effect for a tractor, stabilizing for a pusher; is this due to the turning of the free stream air to align with the propeller axis with change in angle of attack? We've discussed numbers here recently, and I know the WWII fighters tended to lose about 5% stability. I'd expect this effect to decrease with decreasing engine power, and decrease with distance to the center of gravity, but haven't found estimation techniques.
2) I'd imagine that the "masking" effect of the propeller slip stream over tails, etc, would have a destabilizing effect (as the impact of an angle of attack change is less visible to the surface, causing less of a change in lift on the tail). This should be destabilizing for centerline tractors and pushers, and potentially stabilizing for wing-mounted twins (wings in propwash, stab not in propwash)... right? How does this compare to the first effect?
3) Any other effects I should think about?
1) I know there's a major destabilizing effect for a tractor, stabilizing for a pusher; is this due to the turning of the free stream air to align with the propeller axis with change in angle of attack? We've discussed numbers here recently, and I know the WWII fighters tended to lose about 5% stability. I'd expect this effect to decrease with decreasing engine power, and decrease with distance to the center of gravity, but haven't found estimation techniques.
2) I'd imagine that the "masking" effect of the propeller slip stream over tails, etc, would have a destabilizing effect (as the impact of an angle of attack change is less visible to the surface, causing less of a change in lift on the tail). This should be destabilizing for centerline tractors and pushers, and potentially stabilizing for wing-mounted twins (wings in propwash, stab not in propwash)... right? How does this compare to the first effect?
3) Any other effects I should think about?