Originally Posted by
Centaurus
While training crews in Asia who were used to their company procedures (not necessarily Boeing FCTM procedures), it was noticed they tended to completely cancel reverse thrust at the 60 knots call during the landing run. At the call of 60 knots, they would slam the reverse thrust levers fully down from full reverse (Boeing 737). This would cause the aircraft to momentarily accelerate down the runway while the pilot was still also applying the brakes. The reason being the N1 would be still running down through around 60% N1 when the reverser lights went out; thus giving momentarily significant forward thrust.
It wasn't until the English second language pilots were advised to carefully read (and understand) the FCTM instructions about the need to allow the N1 to reach idle reverse before cancelling, that the penny dropped they were doing it all wrong.
It got me thinking about landing with loss of all hydraulic braking capability - rare though that possibility could be, of course. The scenario in the simulator was concerned with the use of reverse thrust and the aircraft managing to stop still in full reverse right at the end of the safety area with a nasty drop at the end. How do you cancel reverse when stopped without the residual forward thrust inherent with cancellation from full reverse, trickling the aircraft over the cliff?
OK - I confess it is a bit far fetched but sometimes a bit of lateral thinking doesn't do you any harm; especially if there is nothing in the book about such a non-normal. And neither does there need to be.
Answer? At the moment the aircraft stops right at the end (your lucky day) cut both start levers while the engines are still at full reverse. With a bit of luck, there will be little or no forward thrust to roll you over the cliff with no brakes.
Writer quickly exits stage left..
Had this happen in a light jet, Citation bravo. Has a seperate hydraulic system for the brakes and we lost all the fluid. I diverted to the longest runway, used the reverse to slow down to a complete stop. I had my hand on the emergency nitrogen powered emergency brake in case I needed it but wanted to avoid using it if I didn't have to because of the extra maintenance. So after I stopped I felt it started moving backwards, so I selected forward idle on one of the engines, stopped, shut both down, and we stood still long enough for the fire department to chock the nosewheel.