Helicopter Sikorsky H-37A Mojave Serial 56-127 Register 57-1661 used by US Army Aviation Army. Built 1959. Aircraft history and location Aircraft History 57-1661 US Army Aviation 1959-07-07Sikorsky S-56, c/n 56-127, ff:? del US ARMY as H-37A, 57-1661, 07Jul59 redesig CH-37A, Oct 62 conv CH-37B, unk wfu & soc unk. Send Updates Use APP to upload photo @ (optional) When Now? / / Send