American Airlines Flight 136 was flying over Newfoundland early this morning on its way to London, when the pilot diverted back to New York's JFK airport -- all because of what authorities call a 'misunderstanding'.

The plane had started its journey last night at LAX.  It had taken off around 8 PM, bound for Heathrow.  A couple of hundred passengers were on board the 777.

A flight attendant became suspicious of one of the male passengers, who happened to be Middle Eastern. She told the captain.  He turned around the plane.

When it landed in New York, federal authorities came on board and took the passenger into custody.

Exactly what made this passenger 'suspicious' is still a mystery.

At first, Homeland Security Chief Michael Chertoff said the man was an airline employee who somehow bypassed security.

Then the airline indicated he wasn't an employee, but he had taken the airline employee shuttle bus at LAX, which raised suspicious.

Now the TSA says he was just a regular passenger who did NOT take the bus, and who did go through screening without incident.

So who knows what the reason was.

One thing's for sure though:  for the passengers, it was a big incovenience.

By the time they arrived at JFK, it was the middle of the night.  The plane couldn't take off again because the crew had already worked too many hours.

The airline was hoping to get them to London sometime today.

These days, if anything seems out of the ordinary, that's a good reason to fear a terror attack.

Secretary Chertoff says he has a 'gut feeling' terrorists could strike the U.S. this summer.

Is it any wonder that flight attendant was extra cautious?