What was found
ON FLIGHT 4451 ABOUT 10 MINUTES AFTER TAKEOFF THE CREW RECEIVED A BLEED NR 1 LEAK INDICATION MESSAGE. THE CREW FOLLOWED THE CHECKLIST AND THE BLEED LEAK WENT AWAY. THE CREW ELECTED TO RETURN TO JFK. THE CREW DECLARED AN EMERGENCY AND LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. REMOVED AND REPLACED THE DUCT LINE BEHIND PANEL 271DLW IN THE CARGO COMPARTMENT IAW AMM 36-11-09. LEAK AND OPERATIONAL CHECKS ARE NORMAL. THE AIRCRAFT RETURNED TO SERVICE.