Helicopter Sikorsky S-55 Serial 55-884 Register C-GRXP N745A used by Humble Oil and Refining Company. Built 1955. Aircraft history and location Aircraft History N745A Humble Oil and Refining Company 1955-06-25Sikorsky S-55 c/n 55-884, ff:? del Humble Oil as N745A, 25Jun55. C-GRXP - S-55T N2298L 1982-09-25 A CYYC at Calgary Intl. Send Updates Use APP to upload photo @ (optional) When Now? / / Send