Where I fly, "land after" clearances are quite common, especially for the local instructors, whose capabilies the controllers are very aware of.
So I was quite surprised when I found myself in the following scenario a few weeks ago. I called "final". ATC replied "Continue, one vehicle on the runway to vacate". The vehicle was about half way down the 1800m runway. Even on a really bad day, I can land my aircraft and stop quite safely in around 600m.
So, even without allowing for the distance the vehicle would travel in the time it took me to reach the runway (it was travelling away from me), I was confident that I could land safely. I informed the controller I was "visual with the vehicle, can accept a land-after". The controller replied "I can't do that, continue approach". By this point, I was approaching the numbers. A go-around was a definite option. The alternative option was to add enough power to fly along the runway at about 10' until the vehicle had vacated, and I was cleared to land - an option which, given the size of the runway, was perfectly safe.
So that's what I did. Before too long, the vehicle vacated, I landed, and was off by the taxyway which is half way down the runway - so still had half the runway to go. Perfectly safe.... but still far far less safe than the "land after".
Afterwards, I asked the controller what was going on. Turns out that although he can clear me to land after an aircraft, he's not allowed to clear me to land after a vehicle. I didn't know that!
As Vintage ATCO says: "Logic in aviation. . . . Lemme think about that.
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