Helicopter Sikorsky S-55 Serial 55-792 Register 9621 used by Royal Canadian Air Force (1945-1968). Built 1954. Aircraft history and location Aircraft History 9621 Royal Canadian Air Force (1945-1968) 1954-10-20Sikorsky S-55 c/n 55-792, ff:? ordered by P&WC for RCAF del RCAF as 9621, 20Oct54. Send Updates Use APP to upload photo @ (optional) When Now? / / Send