Helicopter Sikorsky S-76B Serial 760348 Register N591AK used by Unical Defense Inc. Built 1989. Aircraft history and location Aircraft History N591AK - Rotary Wing Air Charters Llc at Farmingdale, NY Feb11-Sep19 Unical Defense Inc 2019-09Unical Aviation Inc at Walnut, CA from Sep19 Send Updates Use APP to upload photo @ (optional) When Now? / / Send