Another set of seats was discovered to be loose on an American Airlines flight yesterday just days after another plane had to make an emergency landing because of the same problem. This time, loose seats were discovered on an American New York to Miami flight, and the plane was forced to return to JFK. The last incident occurred Saturday on a Boston to Miami flight, and the plane also landed at JFK. American officials don't believe either problem is linked to its labor troubles. The FAA is investigating both incidents. American has grounded eight planes as it continues to look into the problem, reports ABC.