Boeing makes it clear.
U cannot land with the AT engaged. It would simply increase thrust to maintain speed...causing a low level flyby in the landing config.
They also say, if the AP is off, the AT should not be engaged.
Now i don,t remember wx or not it's explicitly stated, but it's safer to fly the approach with the AT armed, since the pushing the TOGA swiches in this setup wil initiate the GA sequence. Same thing on the 777. Flying with the AT OFF, it can be stalled, however, if u fly the approach with the AT ARMED, it will "wake up" to prevent a stall.
Last edited by Check Airman; 20th July 2006 at 21:17.