What was found
(CAN) DURING THE TAKEOFF IT WAS NOTICED THAT THE NR 3 MAIN WHEEL HAD GONE FLAT. THE ACFT RETURNED TO THE DEPARTURE AIRPORT. AN EMERGENCY WAS DECLARED FOR LANDING AND THE ACFT LANDED UNEVENTFULLY. THE NR 3 AND NR 4 MAIN WHEEL ASSEMBLIES AND BRAKE ASSEMBLIES WERE REPLACED. THE RT AFT INBD MLG DOOR WAS DAMAGED AND WAS ALSO REPLACED. THE TIRE THAT WENT FLAT WAS A RETREADED TIRE. THE TIRE ASSY WILL BE SENT TO THE VENDOR FOR ANALYSIS. MAIN WHEEL ASSY, PN 3-1573-1, SN 2855. ACFT TSN 6425, CSN 4363. NR 3 MAIN WHEEL ASSY TSR 395, CSR 247.