Unmanned Systems Technology 027 l Hummingbird XRP l Gimbals l UAVs insight l AUVSI report part 2 l O’Neill Power Systems NorEaster l Kratos Defense ATMA l Performance Monitoring l Kongsberg Maritime Sounder

64 O ’Neill Power Systems is a start-up company based in Fall River, Massachusetts, which has developed and patented a unique propulsion solution with great potential for helicopter-type UAVs. Its NorEaster engine was originally conceived by company CEO Jim O’Neill, and has been further developed by Bob Norton, an engineering professor from the Worcester Polytechnic Institute (WPI) in Massachusetts, who has since become O’Neill’s chief engineer. It is a four-stroke, 80 hp radially arranged eight-cylinder reciprocating unit. It has two output shafts, integrated coaxially, to drive two counter-rotating propellers. Opening the engine housing reveals a drive transmission system that relies not on a crankshaft or turbine but on a cam-based mechanism that is unlike anything seen elsewhere. Rather than being developed to target one or two specific engineering problems or requests from UAV operators, the NorEaster is designed to replace existing helicopter drive systems entirely, thus resolving the myriad issues associated with them. The NorEaster’s history The CEO’s inspiration for the engine came to him in 1969, when he was stationed in South Korea on military service. “Although I wasn’t a helicopter pilot, I spent a lot of time on helicopters, just as a lot of my associates were doing in Vietnam,” O’Neill explains. “What I noticed back then about conventional helicopter designs is that the tail rotor is incredibly vulnerable. Even if you’re well-clear of enemy combatants, it’s so easy for the rotor to get knocked and disrupted by the branch of a tree or some other obstacle.” The tail rotor is also a significant source Rory Jackson examines the development of this radial engine for helicopter-type UAVs that uses a cam-based mechanism for its drive transmission A question of timing August/September 2019 | Unmanned Systems Technology The NorEaster uses two concentric output shafts to drive counter- rotating propellers, negating the need for a tail rotor (All images courtesy of Peter Casey, O’Neill Power Systems)