Originally Posted by
OnTheNumbers
First Officer is pf, weather is at minimums. They are expecting to see the runway at minimums. At minimums they see the runway and the first officer disangages the autopilot but at the same time he presses the toga buttons. Captain takes over and lowers the nose and retards both thrust levers to idle, they land at idle thrust and aircraft was dispatched with one reverser inop. The captain deploys the thrust reverser of the left engine and releases the right engine. Since he hadn't disconnect the auto throttle right engine goes to TOGA thrust. Aircraft starts to accelerate and skids off the runway from the left. Right engine saparates. All passengers evacuate the aircraft from the rear door. No smoke in the cabin no injuries.
During landing phase, the aircraft systems receive an "on the ground" information from the Flt/Gnd switches, spoilers are deployed, left engine reverse thrust applied. If in this situation the A/T can command TO/GA thrust on a single engine, I would say that this a serious design flaw.
As far as I know, if the aircraft has been dispatched with the right reverse inop, the reverse mechanism will be locked by the technical staff and if the pilot activates the reverse thrust levers only the left engine would go to reverse mode. Would a pilot in such a situation pull only the left reverse lever or both (instinctively)? Or is there a defined procedure which prohibits the pilots to activate an inoperative reverse thrust lever during landing?
Why I am asking this?
Let's say that the captain as taken over the controls and landed the aircraft safely. If he would activate both reversers the autothrottle would not be able to advance the right thrust lever to TO/GA thrust position because the pilots right hand pulls the levers back. Only after cancelling the reverse thrust the captain can remove his right hand from the throttle. By this time the aircraft must have decelerated to 60 kts. Let's say the right engine goes to TO/GA mode at this point. It would take a couple of seconds for the full thrust to developed. During this time the pilots should have noticed this problem and retarded the thrust levers (in my opinion).