Unmanned Systems Technology 001 | UAV Factory Penguin C | Real-time operating systems | Hirth S1218 two-stroke twin | Base stations | ASV C-Enduro | Composites | Datacomms

21 UAV Factory Penguin C | Dossier Penguin C power module The Penguin C has its 28 cc two-stroke engine at the heart of an integrated propulsion unit, which includes the fuel tank, fuel pump, electrical generator and so on. This allows the power module to be treated as a cartridge that can be swapped in and out with just four bolts to undo and re-tighten. This permits the owner to buy two such modules and keep flying while one is in for servicing. The engine sits with its cylinder upright and its crankshaft running on the longitudinal axis of the aircraft to directly drive the propeller behind. The crankcase is fed through a reed valve located at the front (in the direction of flight). A cooling cowl encloses the cylinder (with just the top of the spark plug projecting through) while a C-shaped silencer wraps around the bottom end. The engine itself is mostly concealed. At the front (the opposite end to the propeller) a firewall wraps around the throttle body assembly, and contains various fuel system components. Whereas the Penguin B has its fuel tank mounted separately from the engine, in the Penguin C that carbon fibre composite firewall – which carries the engine – is cold-bonded to the carbon fibre composite fuel tank to form a single structural unit at the front of the power module. The module attaches to the airframe via four anti-vibration mounts into the firewall. In development of the Penguin series Popiks admits that one of the most challenging aspects has been the creation of a dedicated fuel-injected version of the engine, despite the fact that since UAV Factory does not supply military customers it has not needed to develop its engine to run on ‘heavy’ fuel. The engine is normally mapped to run on regular 98 octane pump gasoline, with 2% of oil mixed in to provide lubrication, but it can be mapped to run on as low as 95 octane pump. Initially, UAV Factory worked with a supplier of a port-injection system that replaced the carburettor with which it had begun engine development. However, it found it necessary to develop an in-house system to obtain the level of performance and reliability it required at a more reasonable cost. Charge air is collected from within the engine compartment and fed to the throttle body through a filter. This is cut down from a K&N motorcycle air filter and is bonded into UAV Factory’s The Penguin C showing the power module extracted from its home in the fuselage Elements of the power module, which embraces the fuel tank, the ECU, firewall, engine, cooling cover, silencer and the propeller assembly Popiks says one of the most challenging aspects was to create a dedicated fuel- injected version of the engine Unmanned Systems Technology | November 2014