Straight / sideways lift

[moot]

Is it an impression only, or do planes lift more when yawed sideways?  If not, why do they?

[bozon]

What do you mean by "lift more"?

If you refer to uncoordinated flight, you loose lift but mostly indirectly - the increase in drag slows you down and the reduction in airspeed reduces the lift. As overall aerodynamics go, the airflow diagonally along the wing means a different effective wing profile and shape - this could have different effects depending on the exact details. I would guess that the biggest disturbance would be near the wing roots where the flow past the stream edge is disturbed by the fuselage being in the way. This would kill the trailing vortex that is crucial for producing the lift.

If you refer to the tendency to lift a wing when kicking rudder, this is caused by the outer wing traveling faster than the inner one (the one pointing into the turning direction) during the yaw motion. It is a momentary effect and will be more noticeable, the larger the wingspan. If you continue into a slide, then the above mentioned start to take effect.

There are other secondary effect associated with yawing, such as roll torque applied by the tail and gyro-effect of the prop. The latter was extremely pronounced in WWI rotary engines where the entire engine was rotating. This caused a pronounced pitch up when turning in the one direction. I didn't notice this in AH when yawing, but when pitching I notice the ball being kicked sideways. It is quite pronounced in the mosquito (two props in the same direction).

[moot]

I mean that if you are taking off, a plane will usualy have enough lift to get airborne at a lower speed if it's put sideways (as far to the side as the rudder allows), wings level, than if its nose is kept straight forward.

Thanks for the explanation.

[swareiam]

Originally posted by moot
Is it an impression only, or do planes lift more when yawed sideways?  If not, why do they?

Moot,

In most single engine aircraft once the aircraft leaves the ground; and is producing high speed and a high angle of attack. The torque effect of the spinning propeller causes the nose of the aircraft to pull to the left. The is counteracted by applying right rudder pressure during the climb.

The only way normal aircraft produce additional lift from straight and level flight is to increase acceleration. If you introduce any sort of rudder action during normal straight and level flight, less wing surface will be exposed to the oncoming air which will decrease the lift capacity of the wing. The introduction of rudder pressure causes a maneuver called a CRAB. This is when the side of aircraft is moving into the oncoming air, in turn causing the aircraft to loose altitude.

Pilots use this maneuver to slow the aircraft down abruptly. It can be used at any altitude and just about any speed, depending on the aircraft. It is definetly good ACM.

So, if your on take-off roll you rotate and your kicking anything but right rudder to counteract torque effect at high speed and high AoA. There are two things that will happen; 1) You will be off coarse drifting to your left, this is with no correction. 2) You will feed into the torque effect of the prop and the aircraft will begin to loss lift capacity with a big turn to the left. This is adding left rudder pressure during take-off, which is not recommended by any means. HTC was nice enough to take care of these little flight dynamic issues for us, so that we can have some fun fighting.

Anyway, aircraft produce lift in straight and level acceleratted flight.

THRUST + LIFT > DRAG + WEIGHT

Cheers:aok

[hitech]

You could also be seeing the decrease in IAS do to the side slip changing the angle on the pitot tube relative to the wind. So it appears you are lifting of at a slower speed.

[hitech]

Also has anyone else had there airspeed indicator stick for the first time when on the vertical up line of a hammer head?

[moot]

Thanks guys