The German engine manufacturer 3W-International is offering heavy fuel (HF) engines that can be used for helicopters, fixed-wing aircraft and vertical take-off and landing (VTOL) aircraft. Here the spectrum of two-stroke HF engines ranges from a one-cylinder engine with 3hp up to a four-cylinder engine with over 60hp. An HF-driven Wankel engine was introduced in 2017. See story here.
3W-International delivered the first HF-engines in 2009. Since then, thousands of HF engines were sold worldwide. "Principal customers are military and safety-relevant applications," Karsten Schudt, Managing Director of 3W-international, explains.
HF-based internal combustion engines can demonstrate their strength during missions for humanitarian purposes in disaster areas according to the Managing Director. Most unmanned aerial systems (UAS) equipped with 3W-International engines are unarmed and deployed for reconnaissance and surveying tasks. These reconnaissance UAS also come into use during disaster and humanitarian deployments to provide a quick overview of the crisis region. UAS with heavy fuel drives can play a decisive role during these deployments, as their structure and technical specifications are specifically designed. Fuel used on 3W-International HF engines are JET A-I, JP-5, JP-8 and a 2-stroke mixture of 2% Aspen oil and 0.1% diesel valve cleaner.
Mr. Schudt explains that transport of foodstuff and medications for first aid in crisis areas is possible only to a limited extent due to the degree of destruction. Helicopters generally assume the main task. Here UAS play an important role here even though their transport capacities are much smaller. "UAS can be quickly relocated to a crisis region, meaning that reconnaissance tasks can be undertaken early on," he says. "You're more independent since only one pilot is need, who doesn't necessarily need to be on site. The limited use of autopilots is also feasible. The necessary on-site infrastructure is minimal, and so are the deployment costs. Furthermore, HF-driven UASs are also fuel-independent."
One assumes that military and rescue and aid organisations active in crisis regions would have sufficient diesel and gasoline available on site. Two-stroke HF engines can be driven with available gasoline since they operate with a two-stroke mixture of gasoline, 2% Aspen oil, and 0.1% diesel valve cleaner. Kerosene, which is used for helicopters, can likewise be used. "Our 2-stroke HF engines can thus be very flexibly deployed," Mr. Schudt tells MONS. "The engine doesn't need to be purged when switching between fuel types, which extremely simplifies the deployment. Performance declines briefly at the moment when fuels are switched, but then quickly re-establishes itself at the same high level."
The performance engines from Germany are used in both fixed-wing aircraft and helicopters. "HF technology yields quite clear benefits for these UASs' operators," the industry expert concludes. "The engines are very flexible and reliable, and they diminish the costs of deployments. Simpler deployment planning is also possible thanks to the fuel independence. On-site logistics is likewise less costly. These cost savings, especially on the part of the employees needed to operate the UAS, are of interest for our customers."