Why is Yaw 2nd effect of Roll? (and explain Trim)
Why is Yaw 2nd effect of Roll? (and explain Trim)
Why is Yaw 2nd effect of Roll?
You need to qualify that statement, yaw is the secondary effect of UNCORECTED roll
When the aircraft is banked the resultant of lift is inclined away from the vertical producing a decrease in the lift required to maintain level flight. The loss of lift causes the nose to fall towards the downgoing wing which can be seen as yaw. Corrected roll, whereby level flight is maintained by an increase in CC back pressure does not produce the secondary effect.(needs supporting diagram or model)
explain how the trim works accurately and simply - why when we change airspeed does the plane need re-trimming and therefore why trim cannot be finalized until airspeed stabilizes?
Speed is directly proportional to the production of lift so when airspeed is changed this produces a change in lift which either produces a nose up moment or nose down moment, (normally speed up, nose up and vice versa) If the pilot attempts to maintain the original attitude this trim change is felt through the CC by the pilot as a loading. This loading can be removed by aerodynamically producing an equal and opposite force by moving a small aerofoil surface known as a trim tab.(needs supporting diagram or model). As the speed changes so generally will the trim loading , when the speed stablises the trim loading change will remain constant.
I would also mention that the Tiger Moth has a trim wheel which uses a mechanical opposite force EG a big spring! This helps to explain force.
The above are very simple explanations and I am amazed there have been so many posts without adequate simple replies.
ASK CAPTAIN JON
Last edited by rondon9897; 28th Mar 2007 at 13:36.