But what would be the yield if BA put a long-haul aircraft on the route instead? Could BA still charge £1K per seat with a larger aircraft, or would it have to reduce prices to get the optimum revenue from it? What would be the profit made by that aircraft that day? And how much profit would BA give up on the normal long-haul rotation that the aircraft would otherwise operate?

Although only insiders would know what the actual numbers are, it's not difficult to imagine a scenario in which it is more profitable for BA to use its capacity/resources in the usual way and just rake in the high-yield fares on the short-haul route than to increase capacity on the short-haul route by cancelling a long-haul rotation.