Alternate law has a low speed and a high speed stability (1.27.30 2/3)both of which can be overridden by a pilot.
At low speed a nose down demand referenced to IAS is introduced and the law changes to direct(stick to surface).High speed stability introduces a nose up demand but pitch protection is lost.
To answer BOACs question the answer is there is no button to force a law change.
Last edited by tubby linton; 18th May 2011 at 15:56.
Reason: speeling!