Originally Posted by
Leonakua
Yes. If the plane bounces, it has not landed. In less than three seconds all four translating cowls could shut and Toga would be two seconds away. So, yes.... TCMA can NOT be programmed to frustrate or foul a feasible escape maneuver.
With respect, Leo
(During a landing, if a pilot initiates a go-around after having already deployed the thrust reversers, they must first manually stow the reverse levers before the TOGA switches can be effectively used or the forward thrust levers advanced.) GEnx. Do cascade reversers actually reverse thrust? Or, divert N1 sideways.
- Airbus and Boeing both state that once thrust reversers have been selected, you are committed to landing. Failure of reversers to stow occurs, especially as reversers are usually locked out (stow or retract) while airborne. If you leave the ground with a reverser deployed, it will not stow until you return to the ground. So you are potentially trying to do a go around with one engine stuck in auto-idle with the doors open causing high drag.
- The classic case for when TCMA would be critical is if you attempted to deploy or stow a reverser and the engine returned to full power uncommanded. You could then have one engine in full forward thrust and one engine in full reverse thrust. TCMA would activate to ensure that the engine is either a) doing what you ask it to, b) at idle because the reverser has failed, or c) shut down because the FADEC can't return the engine to idle.
See this video for an example of why you don't try to go around after reverse is selected. This is a 767, without TCMA. Once off the ground, the reversers cannot deploy or stow and are stuck where they are, with the engine stuck at auto-idle because the reversers are not in the commanded position.