How did pilots overshoot landing?

WASHINGTON (AP) - Were the pilots distracted? Catching up on their sleep? Federal investigators struggled to determine what the crew of a Northwest Airlines jetliner were doing at 37,000 feet as they sped 150 miles past their Minneapolis destination and military jets scrambled to chase them. Unfortunately, the cockpit voice recorder may not tell the tale.

A report released late Friday said the pilots passed breathalyzer tests and were apologetic after Wednesday night's amazing odyssey. They said they had been having a heated discussion about airline policy. But aviation safety experts and other pilots were frankly skeptical they could have become so consumed with shop talk that they forgot to land an airplane carrying 144 passengers.

The most likely possibility, they said, is that the pilots simply fell asleep somewhere along their route from San Diego.

"It certainly is a plausible explanation," said Bill Voss, president of the Flight Safety Foundation in Alexandria, Va.

New recorders retain as much as two hours of cockpit conversation and other noise, but the older model aboard Northwest's Flight 188 includes just the last 30 minutes - only the very end of Wednesday night's flight after the pilots realized their error over Wisconsin and were heading back to Minneapolis.