GYS,
It is mandatory to read back the terms of a conditional clearance. At least in lil ol' NZ. There are other guidelines/requirements relating to zero risk of misidentifying the a/c concerned.
Also we have a (minor) difference in the required phraseology for a line up behind an arriving a/c, vs lining up after a departure. In the first case it's "Behind the Boeing short final line up behind." And inthe second it's "After the departing Boeing line up behind" . Small difference;questionable effectiveness; perhaps a bit subtle for many, but it's something.
It is also not permitted to offer a conditional line up unless it is behind the next a/c to use the runway. Eg: "Behind the 2nd Boeing at five mile final line up behind" is not on (nor would it ever be necessary). It is not necessary to identify the aircraft by airline/colour etc unless there is a risk of confusion.
There are (at least) two issues in this thread, The safety (or not) of conditional clearances, and the issue of the FAA withdrawing a useful and usually perfectly safe tool. Additional nclude the choice of phraseologies around the world to express the same idea, and whether phraseology use or misuse actually contributes to runway incursions. Sorry to state the bleedin obvious, but if an a/c is lined up waiting its turn to go, and the controller then clears someone to land on that runway, its not the phraseology at fault. And if it happens more than once, error tolerant systems need to be put in place tout sweet. (In our place it only took 3yr to get a more error tolerant system after a critical deficiency was identified
