Unmanned Systems Technology 015 | Martin UAV V-Bat | William Sachiti | Sonar Systems | USVs | Desert Aircraft DA150 EFI | SeaCat AUV/ROV | Gimbals

50 I n aviation, a lot of emphasis is placed on time-proven dependability to minimise the danger of accidents or crashes with craft. The best engines will enjoy decades of service as newcomers struggle for approval. Desert Aircraft has a diverse range of small- displacement two-strokes suitable for UAV use. Since it started producing engines, 20 years ago, it has sold the best part of 50,000 units across that range, mainly for model aircraft. Its primary offering for the UAV market though is still its first ever design, the DA150 horizontally opposed twin. This time-honoured 150 cc air-cooled two-stroke started life with a carburettor, but over the past few years Desert Aircraft has cooperated with HFE on fuel injection. HFE was featured in UST 09 (August/September 2016) with a Dossier on its marine powertrain, which was a development of a small-displacement four-stroke to suit the needs of an autonomous buoy. There are now two fuel-injected versions of the DA150 EFI – regular and Mil-Spec. The latter has a port injection system developed by HFE in conjunction with Currawong Engineering. That company was featured in UST 12 (February/March 2017) in the context of its work for the Cobra A33 single-cylinder Ian Bamsey uncovers the engineering behind this time-honoured UAV engine, which now has fuel injection Tried and tested August/September 2017 | Unmanned Systems Technology Desert Aircraft’s straightforward DA150 UAV two-stroke twin (All photos: Lawrence Butcher)