Mad....you do make some very interesting points but I have to say that I agree with Heathrow Director. I
do put safety above all else, but the arguement that you make could be taken even further. There have been numerous incidents involving a/c in the circuit....should we ban circuit traffic? Should we leave all departing a/c on their SID because giving vectors/climb throughs to expedite departures is less safe? Facetious I know, but the only way to make ATC 100% safe would be to not allow a/c to get airborne at all!
I can actually think of incidents where the situational awareness provided by a conditional clearance would possibly have prevented an incursion. Imagine a vehicle calling to enter the runway, which the ATCO assumes to be the one he can see at A1. Actually it is another vehicle at an intermediate holding point. An "after the landing..." clearance would not result in a runway incursion and would be quite safe...the "wrong" vehicle would wait until the landing a/c had passed before entering the runway. However, a direct clearance to enter the runway as the landing a/c touched down could be disastrous, as a vehicle has now been cleared onto the runway ahead of it!
Sir Herbert...we tend not to pass any traffic information to a/c at the holding point which could be misconstrued as a conditional clearance eg "I'll get you away after the next inbound". I know that the chance of such info being mis-interpreted is remote, but it's less safe than using an actual conditional clearance. It's Catch 22! Thanks again for taking such an interest, it's great to have a pilot's perspective on all this
