- Wingspan: 4 m
- Cruise speed: 55 knts
- Maximum take-off weight: 35 kg
- Power plant: 2 x OS GF40 (two 4-stroke petrol engines)
- Payload capability: 5 kg
- Flew at Farnborough International Airshow 2016
Spotter (Southampton Platform for Observation, Tracking, Telecommunications and Environmental Reconnaissance) is a twin engine, twin boom monoplane. The single cylinder, four-stroke petrol engines are mounted in a tractor arrangement to the two nacelles, which also house the avionics and interface with the wings, tail boom and main landing gear. The nacelles are separated by the central wing, which also serves as a fuel tank and features a pylon to which the interchangeable payload pod is attached. The two carbon fibre booms support the horizontal and two vertical stabilisers, as well as a pair of steerable tail wheels. The configuration not only provides propulsion system redundancy, but also allows the interchangeable payload pod to be placed close to the aircraft’s centre of gravity and provides it with an unobstructed forward view. Use of quick release fastenings allows for rapid and assembly and disassembly.
The aircraft has an empty mass of 24 kg, classifying it as a Light UAS and was designed to undertake a multitude of tasks primarily associated with a maritime environment. These include environmental monitoring, search and rescue, and tracking of shipping movements. Spotter is a direct development of the 2Seas20 UAS produced by the University of Southampton, and incorporates a number of improvements.
Safety and redundancy of the system were key considerations throughout the design process that resulted in a 35kg maximum take-off weight UAS with a duplex redundant avionics system capable of flying under manual conventional RC control, autopilot stabilised manual control or autopilot control via the ground control station.
The airframe is largely made of laser sintered (3D-printed) parts and carbon fibre spars, which required minimal manual finishing and therefore reduced potential sources of error and deviation from predicted properties. Upgrades to the UAS that enhance the systems safety are continuously developed and their introduction is subject to a rigorous testing routine.