Helicopter Sikorsky H-37A Mojave Serial 56-036 Register 55-611 used by US Army Aviation Army. Built 1957. Aircraft history and location Aircraft History 55-611 US Army Aviation 1957-08-03Sikorsky S-56, c/n 56-036, ff:? del US ARMY as H-37A, 55-611, 03Aug57 redesig CH-37A, Oct 62 conv CH-37B, unk wfu & soc unk. w/o 02may66 Send Updates Use APP to upload photo @ (optional) When Now? / / Send