Helicopter Sikorsky HO4S-2 Serial 55-144 Register 55144 used by Royal Canadian Navy (1945-1968). Built 1952. Aircraft history and location Aircraft History 55144 Royal Canadian Navy (1945-1968) 1952-04-09Sikorsky S-55 c/n 55-144, ff:? ordered by Pratt & Whitney Canada for Royal Canadian Navy as HO4S-2, 55144, 09Apr52 w/o 1957. 1955-04-29HO4S-2 RCN d/d 29apr55 w/o 25jun57 McNabs Island Halifax Harbour used as ground instructional airframe Send Updates Use APP to upload photo @ (optional) When Now? / / Send