Pugilistic Animus & Bearfoil
Here are the bits from a manual that I'm specifically referring to:
Roll Rates
Speed brake usage, flap position, gross weight, altitude and hydraulic
system operation all affect roll rates. At the same airspeed with flaps down, roll capability increases withreduction in gross weight. In other words, roll rate capability is a function of angle of attack, and, for different gross weights at the same angle of attack, the roll rate is almost the same. Since all normal approaches to landings are made at approximately the same angle of attack regardless of weight, the pilot will probably not notice any
difference in roll capability on final approach. However you may notice
that the aircraft feels more responsive in roll when flying the fixed
speed schedule at light weights.
Yaw Control – Rudder
In comparison to the ailerons, the rudder is very powerful and, due to
the swept wing, small rudder movements cause considerable roll as a
secondary effect.
So Pugilistic Animus, I am talking about roll capability, which I interpret here as roll rate for a given control input. Might be wrong on this though. I just can't quite get my head round why a lower gross weight increases roll capability.
Bearfoil
Why wouldn't a straight, non-swept wing also gain more lift as the aircraft yaws? Doesn't it's outboard wing also speed up relative to the inboard wing as the aircraft yaws - and hence gain lift, inducing roll? Or indeed, why is this effect greater on a swept wing aircraft?