A cycle is counted as one landing. There was another thread going in the tech log where the FAA proposed puting solid restrictions on flight time/cycles of aircraft. As it stands now, certain aircraft have deal breakers to take them OOS eg: I believe if you crack a wing spar on a DC8 the airframe is to be scrapped. I also know of an operator that is scrapping DC9's if damage is found to the aft pressure bulkhead.