What was found
JUST AFTER TAKEOFF, ON FLIGHT NR 7797 THE PILOT RECEIVED A FIRE WARNING. HE DECLARED AND EMERGECY AND RETURNED. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE DISCOVERED THE FIRE WARNING TEST BUTTON HAD FALLEN OFF CAUSING A FALSE WARNING. MAINTENANCE REINSTALLED THE FIRE WARNING TEST BUTTON. FOUND FIRE TEST BUTTON LOOSE. MAINTENANCE THEN REMOVED AND REPLACED THE FIRE TEST BUTTON. AIRCRAFT RETURNED TO SERVICE. (K)