相关题目
The flight altitude or flight level for each aircraft is （ ） by the relevant ATC unit.
Over mountainous region and plateau area the safe altitude along air route is （ ） m，above the highest elevation within 25KM on each side of the centre line of the air route.
The principles of ATFM are that major measures are taken （ ） aided by （ ）measures; holding would rather be conducted （ ） than （ ）.
The mission of undertaking special flights is made known by （ ） according to instructions from higher-ups.
The pilot-in-command or his representative shall （ ） a flight plan to the relevant ATC service at least one hour before the estimated time of departure.
The 11 FIRs in China are （ ） .
To approach and land on the same runway, the preceding heavy aircraft should maintain a minimum wake separation of （ ） km with the succeeding aircraft with wake turbulence medium.
Aircraft separation under radar surveillance should be at least （ ） on approach.
Only with ATC permission is an aircraft of higher speed allowed to overtake the slower one on or before downwind leg, and overtaking should be made on the outer side of the pattern with a lateral separation of （ ） meters.
Except in the case of （ ） landing, no aircraft is allowed to overtake any other aircraft on the inner side of the traffic pattern.
