Brokenspectre: We would notice it as soon as the track did not do what we expected based upon the instructions we have given. If it is a heading then it might not be critical, but a wrongly set altitude/flight level might only become apparent as a level bust or a level off higher or lower than expected. Only this morning I sent an A319 direct to a point which should have taken him left and he turned right by some 25 degrees. Not a problem in itself, except that 6 miles behind him was another A319 of his own company who I had sent off to another point to the right and derestricted the speed control once he was on track. When they closed to within 5 miles (still with vertical separation) I queried where the first one was going. A slight pause and "Err,.. the point you sent us to was not on our route so we weren't sure" Well why did you allow the aircraft to come off the radar heading direct to some other point? As has been said many times: if you're not sure, ASK AT THE TIME!
With regard to your second question, I would hope that the Captain/PNF would query any misunderstanding like that. How could the Captain be certain that he and not the FO was correct?
Bookworm: What do you think close on £1bn has been spent on down at Swanwick? Why, electronic coordination to reduce the amount of verbal communication that has to go on. Take a read through the pages of this Bulletin Board to see how successful that has been!! Come to think of it, an A level IT student might have made a better job of it than our 'experts' have done!
[ 18 November 2001: Message edited by: eyeinthesky ]