Whereas today’s small helicopters have one or two engines, the Autocopter, for enhanced safety, will have triple redundant engine, drive and flight control systems.
The ‘engine’ is however not like a normal helicopter engine that sends drive to the main and tail rotors through a gearbox. It’s actually a generator and much smaller than a typical helicopter engine of the same power. There are three engines because Horizon plans to offer competition-beating new levels of safety. For maximum safety and all-weather, day/night capability over built-up areas, today’s aircraft require a Category A certification which means that, should one engine fail at any stage, the aircraft can safely continue its flight. The Autocopter goes several steps further. If one engine fails, the flight can continue to its destination. If two fail, then the aircraft would fly on at 100kts, maintaining height, as an autogyro. Only in the unlikely event of all three engines failing would the aircraft have to be flown to an autorotative landing. Three engines as opposed to two does mean a weight gain but Horizon believes that’s an advantage. No pilot likes the thought of an autorotative landing, especially if it’s in a built up area and he’s a non-professional, low hours pilot. As the saying goes: ”A good autorotation is one you can walk away from”.
The flight control system uses a Distributed Integrated Modular Avionics (IMA) architecture because of a feature it offers called Modular Certification. As an entirely new aircraft, Horizon expects to see frequent updates as more and more aircraft are sold and experience accumulates. Mod. Cert. is going to make this much easier and less expensive to implement.