BIK,
Disagree. Direct tracking using the phraseology "track direct to..." should track an aircraft to rejoin its flight-planned track (i.e. the point they are tracking to should be on their flight-planned track). "Recleared direct ...." is another variation; i.e. they in effect amend the route clearance of the aircraft.
In a radio fail scenario, the aircraft told to "track direct to..." will, I argue, continue to do so, and then track via FPL once rejoined at the next waypoint.
The difference between "track direct..." and "amended route clearance" which would effectively have the same effect to the route of the aircraft I maintain is in semantics only. I think
legally they would be considered to be the same thing.
