Uncrewed Systems Technology 043 l Auve Tech Iseauto taxi l Charging focus l Advanced Navigation Hydrus l UGVs insight l MVVS 116 l Windracers ULTRA l CES 2022 show report l ECUs focus I Distant Imagery

67 This widespread and growing trend has motivated several RC engine makers around the world to push their engineering and enhance the quality of the solutions they offer, with several such improved solutions for the professional UAV industry having been featured in this magazine as a result. These include the four-stroke, single- cylinder 40 cc GF40U-FI from OS Engines in Japan ( UST 23, December 2018/January 2019), Desert Aircraft’s 150 cc two-stroke twin the DA150 EFI ( UST 15, August/September 2017), and the 3W-110xi b2 TS HFE FI from 3W International, a 110 cc two-stroke twin ( UST 9, August/September 2016). Most recently, we spoke with MVVS, a well-known name in the RC power world, based in the Czech Republic. Although this maker of two-stroke gasoline engines and electric motors may be the latest company we have featured, it is by no means a new contender in aircraft propulsion: its history and accumulated competencies in aerospace engineering go back almost 70 years. As of the 21st century, it has focused on modernising and enhancing much of its product line to meet the levels of reliability needed in the professional UAV market, while maintaining an engineering philosophy favouring simplicity over complexity. This approach is taken not only to cater to a wide range of users just starting out in the use of commercial UAVs, but also because MVVS has found over the years that simpler engines are more reliable. The foremost result of this is MVVS’ best-selling product in the UAV market, the 116 NP LC INJ. Also referred to simply as the 116, it is a 116 cc two- stroke engine with twin cylinders arranged in a boxer configuration. It is a naturally aspirated gasoline system that outputs up to 8.4 kW when running at 5900 rpm, and also comes with a starter/ generator mounted on the crankshaft that can produce up to 1.1 kW of power, or can also be run as a motor (as with all BLDC or PMAC systems) to drive the crankshaft with additional boost power. Additional features of this engine are represented in its name. The ‘LC’ means it is liquid-cooled, a quality that has made it especially popular among unmanned helicopter platforms, and it is fuel-injected as the ‘INJ’ suggests (with ‘NP’ simply meaning New Platform). A lot of the engine’s design has come from a single-cylinder predecessor called the 58 IRS (a 58 cc engine design expanded into a two-cylinder version, with ‘IRS’ standing for ‘intake rear system’), with a policy of component modularity having arisen out of MVVS’ focus on simplicity. Much of the engine metal is cut in-house using MVVS’ CNC facilities, acquired in MVVS 116 NP LC INJ | Dossier Unmanned Systems Technology | April/May 2022 MVVS often recommends a 30 in- diameter, 10 in-pitch Mejzlik propeller for the engine in fixed-wing operations The ‘LC’ in the engine’s name means it is liquid- cooled, it is fuel- injected as the ‘INJ’ suggests, and the ‘NP’ simply means New Platform