Robert M. Gary wrote:



I thought the same time the first time I was cleared to land on a
runway where the previous guy was clearly not going to be off before I
touched down. Tower explained that two planes can use the runway at
the same time as long as the tower can antisipate separation. I"m sure
some of the ATC guys on this list can explain it better though.

You have it essentially correct. You can land your single behind
another single or twin as long as that guy is 3000 feet down the runway.