aircraft weight

[catch 22]

Can anyone shed light on why aircraft feel more stable and seem to be more predicable on landing when they are heavy? On large aircraft the Vref is based on weight, so why should a very light weight aircraft feel so different?

Thanks :confused

[Genghis the Engineer]

Two reasons by and large,

Firstly gust response (that is how much the aircraft is moved by turbulence) is a function of airspeed divided by wing loading. So a heavier aircraft, or one flying slower will suffer less grief in turbulence.

Secondly, if you're flying a 2-seat light aircraft, extra weight in the form of a passenger is Fwd of the centre of lift, so bringing the CG forwards. So the heavier aircraft is usually one with a more forward CG, which hence has more pitch stability.

G

[john_tullamarine]

Plus at lighter weights one would expect lower rotational inertias about each axis .. the lighter aircraft is the twitchier ...

[Checkboard]

... and at the higher speeds for the higher weights the aerodynamic damping is better, and the control response improves. Roll rates and pitch rates aren't affected by aircraft weight much (although the flight path is.)