3-Modellmotoren's petrol engine was found in the following Houthi weapon system: the Sammad UAV. (UN Security Council, "Letter dated 22 January 2021 from the Panel of Experts on Yemen addressed to the President of the Security Council," 1/21).
"According to the Panel, the engine [used in a Houthi weapon system] derives from a shipment of 21 such engines that 3W exported to Eurowings Aviation and Consultancy of Athens, Greece, in June 2015 (UNSC, 2019, p. 89). The Panel further identified that the engines were resupplied to a company based in Iran, in violation of German law (UNSC, 2020, pp. 110-113)." (Conflict Armament Research, "Evolution of UAVs Employed by Houthi Forces in Yemen, 2/2020)