TCAS can issue commands that exceed the performance capability of the NG.
Why do we turn off the autothrottle on the NG? Simply because you don't know what you will get if you don't. If you are climbing with N1, a manual TCAS descent will not change this. You will then descend with climb N1 and enter overspeed really fast. You will get the overspeed clacker and will have to figure out why, at the same time as you need to fly the aircraft inside the TCAS safe zone. A very common pilot reflex to overspeed is to raise the nose of the aircraft. Not a smart thing to do in this situation.
I've had 3 real TCAS RA's, excluding Monitor VS. Click, click, fly outside the killzone smoothly. The passengers or cabin crew never noticed anything.
Monitor VS are being modified into Maintain altitude (or something to that effect), since pilots don't understand that a Monitor VS doesn't tell you to do anything but monitor. They start to manouver and often will make the situation worse.
I'm not surprised some pilots overreact to RA's. It is normally new pilots, or pilots new to TCAS who do this. I used to think it was a fast, emergency manouver myself when I was first introduced to TCAS. I have had a 200 hr marvel in the right seat who tried to point the aircraft skywards after a TA, not sure what he would hav done with a RA.
Last edited by ManaAdaSystem; 12th June 2013 at 08:22.