Unmanned Systems Technology 008 | Alti Transition UAS | Ground control systems | Xponential 2016 report | Insitu Orbital N20 | UAVs | Solar power | Oceanology International 2016 report

anti-vibration mounting system with no hard connection between the engine and the mount (which is hard-mounted to the bulkhead with screws), a new exhaust system and other changes. The 2.0 litre composite fuel tank is built into the airframe and is connected to the carburettor by a short tube. With the three-blade fixed-pitch propeller attached, the power plant has generated around 4 kg of static thrust in tests. Running on the bench at the planned cruise rpm of 5000, Alti has achieved more than six hours’ endurance with a fuel load of only 1.8 litres of standard unleaded petrol. For the moment, the engine does not charge the batteries in flight as there is no need, but the company is considering this for future versions. It is in talks with a local hydrogen fuel cell manufacturer and may integrate a small fuel cell to run the electrical system and charge the batteries in flight to enable mid-mission hovering and longer hovering endurance. The batteries are the company’s own brand of lithium-polymer units, and have a capacity of 6000-8000 mAh from eight cells connected in series. They power custom-built U7 motors from T-Motor, which are screwed down to a mounting base in the carbon pods via anti-vibration mounts. The motors drive carbon fibre rotors from the same company, which is currently testing 16 and 18 in versions. Advanced electric motors T-Motor’s latest U7 V2.0 motors are available in 280, 420, 490 KV variants, KV being shorthand for the relationship between rpm and voltage. Low KV ratings indicate high torque, and a 420 KV motor will theoretically turn at 10,500 rpm with no load; speeds naturally come down with the aerodynamic loads generated by the propeller. T-Motor recommends 420 and 490 KV motors with the above propeller/rotor sizes. The U7 V2.0 range is built in a 12N14P configuration, indicating a 12-tooth stator and 14 magnets. With a 6 mm shaft diameter, the 420 KV U7 for