Helicopter Sikorsky S-55 Serial 55-910 Register N747A used by Humble Oil and Refining Company. Built 1955. Aircraft history and location Aircraft History N747A Humble Oil and Refining Company 1955-09-27Sikorsky S-55 c/n 55-910, ff:? del Humble Oil as N747A, 27Sep55. 2002-08-31 w/o 31aug02 Lythe Vreek, USA Send Updates Use APP to upload photo @ (optional) When Now? / / Send