CAP413 I extracted the following from CAP413:
‘Land After’ Clearance
A landing aircraft may be permitted to touch down before a preceding landing aircraft, which has landed, has vacated the runway provided that:
> The runway is long enough to allow safe separation between the two aircraft and there is no evidence to indicate that braking may be adversely affected;
> It is during daylight hours;
> The preceding landing aircraft is not required to backtrack in order to vacate the runway;
> The controller is satisfied that the flight crew of the landing aircraft will be able to see the preceding aircraft which has landed, clearly and continuously, until it has vacated the runway; and
> The flight crew of the following aircraft is warned.
Responsibility for separation rests with the following aircraft.
First, a non-UK operator is likely to NOT fully understand the ramifications of the [non]clearance, especially the "responsibility for separation." I have never heard a "land after" [non]clearance, but if I had received one prior to reading this thread, I would likely have responded "Roger; cleared to land after the 737 on short final. I have him in sight." I would have assumed that he simply issued a "prospective" landing clearance that is allowed by FAA regulations in some circumstances (i.e., a clearance based on his assessment that the runway would be clear when I touch down, rather than waiting for the other airplane to actually clear the runway).
How would the controller have responded? Would he have corrected my misunderstanding of the [non]clearance to land? Would he have told me to go around? Would he have merely extended the confusion by repeating, "Negative. Land after..."?
Second, how does the controller determine that "The runway is long enough to allow safe separation between the two aircraft..."? Does he know my [747 Classic] landing distance because he is monitoring my airspeed on final? Does he know that "safe separation" is defined by our Operating Procedures as 'Thou shalt not land when another airplane is on the runway'?
I tend to agree with low 'n slow that such terminology is more confusing than safe when dealing with international carriers...