Taxiing down the tarmac, a jetliner abruptly stopped, turned around and returned to the gate.  After an hour long wait, it finally took off.  A concerned passenger asked the flight attendant, "What was the problem?"

"The pilot was bothered by a noise he heard in the engine," he explained.

"So it took an hour to fix the problem?" she asked. 

"No," he replied, "It took us an hour to find a new pilot."