EFI, Mil-Spec & Rotary UAV Engines / UAV Servos Actuators / Fuel System Parts

Built-to-Order UAV Engines: HFE International Talks to UST

With over 100 different UAV platforms in 28 countries using HFE International’s EFI engine systems, CEO Thomas West takes time out to discuss the patented Genpod® Series of Line Replaceable Unit engines and new projects on the horizon By Sarah Simpson / 16 May 2024
HFE International Talk to UST About Line Replaceable Unit Engines for UAVs
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Leading high-reliability fuel injection engine manufacturer HFE International sits down with UST to talk about the company’s gasoline and heavy-fuel propulsion solutions for small UAVs and exciting new technology planned for the future.

CEO Thomas West expands on the patented Genpod® Series, the world’s first Line Replaceable Unit (LRU) specifically designed for small UAV’s, and it’s success within UAVs such as the Sapphire UAS by Spektreworks, and Space Entertainment Laboratory’s unmanned sea plane.


Thanks for your time today Thomas. HFE International’s UAV propulsion systems are used all around the world, including by the U.S. Armed Forces. Can you tell our readers what key challenges your engines address that make them so well suited to military use?

HFE’s patented Genpod® Series engines are the world’s first Line Replaceable Unit (LRU) specifically designed for small UAVs to make integration into the military supply chain easier and faster. These systems can be platform agnostic.

Military forces can remove the Genpod® from one type of UAV manufactured in Europe, and attach it to a completely different aircraft manufactured in the USA by a different supplier. The modular system unifies fleet operations and allows the government or end customer to buy the LRU as a separate product directly from HFE International or request maintenance on the standardized product.

The full line of engines from 5 hp up to 15 hp use the same mounting interface. This means that a mission requiring light weight and efficiency can use a smaller engine, then on the same day, swap the engine for a more powerful engine when higher speeds or more payload capacity is required.


As an official supplier of Advanced Innovative Engineering (AIE) Wankel rotary engines, can you talk us through the key advantages of these propulsion systems for drones and unmanned aerial systems?

The AIE rotary engines have advanced cooling technology that allows the service life to be increased above other rotary engine alternatives. The SPARCS (Self pressuring air rotor cooling system) removes heat from the inside of the rotor as the blow by gasses push through the crank case and out to an external heat exchanger. The compact rotary engines are also useful for generator integration with fully electric hybrid aircraft. Several projects are in development for various sizes of generator systems using the AIE rotary engines. Contact HFE for more detail.

AIE rotary engines with advanced cooling technology

Do you have any case studies or examples of your solutions being implemented in real-world scenarios, that you’d like to share with our readers?

HFE has EFI engine systems on over 100 different UAV platforms in 28 countries. One very successful customer using the Genpod® system is Spektreworks in Phoenix Arizona. Their Sapphire aircraft uses the Genpod® 100 engine as a pusher configuration. The engine is paired with their VTOL avionics stack to downlink all engine data.

Spektreworks takes advantage of the custom color paint job that makes the engine system match the aircraft. HFE provides the option to color match for an additional fee. Spektreworks also takes advantage of the HFE designed silent muffler system, giving them a much lower acoustic non-detectable altitude.

Spektreworks Sapphire VTOL UAS with integrated Genpod® 100 EFI
Spektreworks Sapphire VTOL UAS with integrated Genpod® 100 EFI

Space Entertainment Laboratory in Japan is another great example of how the engines can be configured. They are currently using the Genpod® Systems for a sea plane that flies to various destinations around Japan and takes readings from environmental sensors in the ocean.

The vehicle can quickly fly to destinations where larger ships could take hours to reach. There are two Genpod® variants on this aircraft. The propellers are counter rotating because this is a twin engine. In order to do this, one engine is configured to run clockwise while the other is counterclockwise. The clockwise engine uses a propeller that is reverse pitch.


What is your approach to customization and adaptation of engines to specific customer needs?

HFE does provide a standard engine package catered to fixed wing aircraft. However, there are many options that can be selected to increase performance, reduce sound, change the color or rotation of the engine etc.

Each engine order is reviewed by an engineer and is built to order. A customer can consult one of the engineers at HFE to receive a list of optional configurations. For hybrid power systems and generator set applications, HFE will work with the customer to configure the engine for the specific generator inertia and loads.


Your DA mil-spec engines are tested from sea level to 10,000 ft, and at temperatures from -40°F to 140°F. What else can you tell us about HFE International’s testing processes and commitment to quality?

HFE is now an AS9100 certified company and committed to continuously advancing the quality of the products. Our engineers are working now to qualify the Genpod® 100 EFI as a Type certified engine with the FAA. This process takes several years but HFE is committed and has financed the effort.

Each component that goes into an engine system at HFE is tested and qualified before the final engine package is assembled. The engines complete a break in cycle and full test procedures to verify exhaust emissions meet pre-defined standards. HFE has purchased new thermal chamber equipment and are testing new materials to expand the temperature range and altitude performance of the products.


What plans do you have within the unmanned sector in the next 12-24 months?

The new focus for HFE is compact generator and power systems. Several projects are being completed to create light weight two stroke and rotary powered gensets for the emerging heavy lift EVTOL market. Advancements in power systems from 500W up to 18kW will be released in the next few years.

Also, HFE will be releasing a modular battery pack that will be certified with the FAA along with the Genpod® 100 powerplant. This battery system is very light and compact, has cell balancing, over voltage regulation and charge controls built in. This 50V battery will be used for starting and load balancing for the Genpod® starter/generator. A new version of the Genpod® will be released that will be sold as a package set including PMU and battery, completing the package for simple integration into any aircraft.

Thank you so much for talking with us today Thomas, it’s been really insightful and we’re excited to see your latest projects come to fruition.

To learn more, contact HFE International LLC: Visit Website Send Message View Supplier Profile
Posted by Sarah Simpson Specialising in digital copy Sarah is an experienced copywriter and researcher. Working with Unmanned Systems Technology Sarah has developed a passion for sourcing unique digital content and a talent for writing about the latest technical innovations in the unmanned sector. Connect & Contact