Trek Aerospace Mule (concept design)

(Image credit: Trek Aerospace)

Mule (concept design)
Trek Aerospace, Inc.
Folsom, California, USA
www.trekaero.com

Trek Aerospace, Inc. is a small engineering company based in Folsom, California, USA. Founded on March 18, 1996 as “Millennium Jet, Inc.”, the company changed their name to Trek Aerospace on July 3, 2002 because people thought the company was building jets. To clarify, SoloTrek was a name for certain models of Trek Aerospace's aircraft. SoloTrek was never the name of the company. The company is dedicated to understanding and improving shrouded propeller performance and efficiency. In the process, they developed their own proprietary CFD (Computational Fluid Dynamics) software, TASPA (Trek Aerospace Shrouded Propeller Analysis).

The company has stated all of their aircraft designs are very flexible when it comes to scalability, electric motors used, propeller types and the type of power source used. That is, all previous conventionally powered aircraft the company has created can be converted to eVTOL aircraft and can be updated with the latest in avionics, electronics, propellers and electric (all batteries or hybrid-electric) power sources. All of the company's aircraft have been designed for advanced air mobility (AAM).

The company has designed and made multiple vertical takeoff and landing (VTOL) aircraft including its exoskeleton backpack "helicopters" using shrouded propellers in the airframe design. Some articles refer to the exoskeleton backpack helicopter as a jetpack, even though there are no jet engines involved in the backpack aircraft. The company has also designed and made watercraft. Trek Aerospace also assists and teams with other companies, large and small, in the design, fabrication, and licensing of projects involving shrouded propellers and/or autonomous control systems. For example, Trek Aerospace built XTI Aircraft Company's TriFan subscale proof of concept (POC) aircraft.

Trek Aerospace Shrouded Propeller Analysis
Testing at NASA and university wind tunnels has validated the accuracy of the Trek Aerospace Shrouded Propeller Analysis (TASPA). Flight testing of both crewed and uncrewed vehicles has further verified the real-world applications of Trek’s technology. The company states their core technology has the highest specific thrust (lb/kW) in the industry. Aircraft designed by Trek define the efficiency curve used in the UBER Elevate white paper.

This efficiency allows aircraft to carry more weight in a smaller footprint. According to the company, their shrouded propellers require less power, use fewer batteries, have a greater payload and have a farther range than other battery powered aircraft. Furthermore, the company states their shrouded propellers have outperformed similar free propellers to airspeeds in excess of 230 mph (371 km/h), negating much of the drag penalty associated with ducted propellers.

Mule heavy-lift air cargo hybrid-electric VTOL concept design drone
The Mule (Mobile Unmanned Lift Enabler) is an autonomous heavy-lift air cargo hybrid-electric VTOL concept design drone. The air cargo drone was originally developed for military in 2002 for use during peace time and war time service. The drone was designed to have ultra-high reliability, have a very low decibel signature, a very low infrared signature and have minimal maintenance in the field. Even though the original aircraft was a VTOL aircraft with a combustion engine, gears and shafts for turning the propellers, the company redesigned the aircraft to be a hybrid-electric VTOL aircraft.

The estimated cruise speed of the drone was 132 mph (212 km/h) and had a predicted range of 150 m (241 km). The air cargo drone has two tilting ducted fans located at the top of the fuselage and can maneuver in all directions of flight which gives the aircraft excellent maneuvering abilities. The aircraft has two front stub wings to help with lift during forward flight and a rear T-tail for lift and stabilizing the aircraft during flight. The fuselage is made from carbon fiber composite to give the aircraft a high strength to low weight ratio. The drone has fixed skid landing gear.

There are lots of sensors on the aircraft such as detect and avoid instruments, cameras, infrared and other sensors needed for remote/autonomous flight. While the drone was never intended to be crewed, the aircraft is scalable and could be designed and manufactured to hold crew, cargo and/or passengers.

The calculated empty weight of the drone is 400 lb (181 kg), with a maximum payload weight of 200 lb (91 kg), has a maximum fuel weight of 100 lb (45 kg) and has a maximum takeoff weight of 700 lb (318 kg). The drone has a detachable cargo pod which located at the bottom of the fuselage and is attached easily with four clips which are permanently attached to the cargo pod. The cargo pod can hold ammunition, first aid kits and other supplies. In the aircraft's current configuration, the cargo pod needs to be manually attached and detached by ground crew. It would be possible at some point in the future, to design the aircraft where the pod could be attached and detached by autopilot, remotely or autonomously.

The aircraft is streamlined and has a small footprint which is useful for landing on small vertiports or unprepared landing areas such as a grassy field or on a road. In addition, the small size of the aircraft very useful for storage in ships, hangars, a garage or tents. The small size of the aircraft also makes the aircraft easy to transport by truck, helicopter or airplane. The aircraft can be transported in a 60" X 60" X 96" (152 cm X 152 cm X 244 cm) crate.

The U.S. Military did not select this concept design aircraft for further development.

Specifications:

• Aircraft type: Hybrid-electric air cargo VTOL concept design aircraft
• Piloting: Autonomous (designed for autonomous piloting)
• Capacity: Cargo only, with bottom loading cargo container
• Cruise speed: 132 mph (212 km/h)
• Range: 150 m (241 km)
• Empty weight: 400 lb (181 kg)
• Maximum payload weight: 200 lb (91 kg)
• Maximum fuel weight: 100 lb (45 kg)
• Maximum takeoff weight: 700 lb (318 kg)
• Propellers: 2 ducted propellers
• Electric Motors: 2 electric motors
• Power source: Hybrid-electric power source. Originally designed for a 120 hp engine. All power output information, including cruise speed, range, maximum payload weight and etc., would be dependent on the technology used as the power source.
• Fuselage: Carbon fiber composite
• Wings: Two front stub wings
• Tail: T-tail
• Landing gear: Fixed skid landing gear

Related Aircraft:

• Trek Aerospace Dragonfly (prototype)
• Trek Aerospace DuoTrek 1.0 (concept design)
• Trek Aerospace DuoTrek 2.0 (concept design)
• Trek Aerospace Elesi (concept design)
• Trek Aerospace FlyKart 1 (prototype)
• Trek Aerospace FlyKart 2 (prototype)
• Trek Aerospace FlyKart 3 (prototype)
• Trek Aerospace LogDrone (concept design)
• Trek Aerospace Nightingale (concept design)
• Trek Aerospace Nytngale (concept design)
• Trek Aerospace OAV-II (concept design)
• Trek Aerospace OVIWUN (production model)
• Trek Aerospace Scorpion (concept design)
• Trek Aerospace SoloTrek Springtail EFV (prototype)
• Trek Aerospace SoloTrek XFV (prototype)
• Trek Aerospace SoloTrek XFVC (concept design)
• Trek Aerospace SoloTrek XFVM (concept design)
• Trek Aerospace TERN (concept design)
• Trek Aerospace Tyrannos (concept design)

Company Insights:

• Crunchbase

Resources:

• Trek Aerospace website
• Trek Aerospace Twitter
• Trek Aerospace LinkedIn
• Trek Aerospace Wikipedia