Hi all
My 757 manual infront of me states that all TCAS RAs are inhibited in the climb until 1100 ft Rad alt. Descend RAs are inhibited in the climb until 1200 ft rad alt. and also inhibited from 1000 ft rad alt in the descent.
Also, if given a descend RA at just above 1200ft in the climb, it will be inhibited as soon as the EGPWS alert activates due to terrain floor closure!
So although you need to descend to avoid colliding with another aircraft, you may have to climb to avoid hitting the ground! Assuming that the other aircraft is TCAS equipped with RA capability, it should work out that you are not descending and tell it to increase climb! In technology we trust!!!
ACA