"Peter" wrote in message
...

Same thing that happens now. If the runway isn't clear when he starts to
land then he does a go around and negotiates a new reservation slot in the
queue. If he's far enough back when the delay occurs then he slows or
does a 360. Certainly the algorithms would be different for ATC than
computer networks ('retransmit after collision' can work for packets but
isn't so good for aircraft), but I don't see it as inherently less
soluable.


What's the backup to the computer?