Despite our revolutionary approach to aircraft design, we believe in a cautious and measured approach to product development. Our first commmercial project is the J103TM, an ultralight aircraft being developed in accordance with the Federal Aviation Administration’s CFR Part 103 rules for ultralight aircraft. Note that technically ultralights are considered a “vehicle” per the FAA, not an “aircraft”, although we’ll refer to it here as an aircraft for convenience. For more information about the legal definition and operating limits of ultralights, please refer to our Ultralight Info page.
​
The Kestrel Aerospace J103TM Ultralight
Most currently available fixed wing powered ultralights are still basically evolved hang gliders with a seat and attached motor, as can be seen in the photos below. The J103TM is being designed from the start to resemble a more traditional aircraft, where the pilot sits inside a fuselage rather than hanging from the airframe, and where there isn't a 60 lb motor with fuel and rapidly spinning propeller above and behind him – important safety considerations in case of an accident!
J103 Specifications
That’s right, the J103 is a jet! This is a true turbojet, not a ducted fan powered by a gas engine or electric motor. In addition to providing a unique and amazing aural experience, the jet provides several design and flight benefits, as discussed more below. The main tradeoff is that jets are thirsty and ultralights are limited to 5 gallons of fuel, so endurance is modest if operating under FAA Part 103 rules for ultralights. The J103 is meant for fun flight in the vicinity of your local airstrip, not for cross-county trips. Nevertheless one of our top design priorities is to further optimize the design to maximize the endurance.
Transport and Storage
The J103 was designed for ease of transport and storage. The wings are detachable, and the tail folds over the fuselage such that the entire aircraft fits easily in a pickup truck bed or small car trailer. It can be readied from the storage configuration to the flight configuration in about 15 minutes. Why wait years on a hanger waitlist and then pay for a hanger rental indefinitely when your aircraft can be stored easily at home?
Assembly and Maintenance
The J103 will initially be offered only as a quick-build kit. All major structure components come precut. It’s mainly a bolt together deal. No welding or fiberglassing is required. Everything required to complete the aircraft will be included in the kit, including the engine and gauges.
Mechanical complexity of the aircraft is similar to a motorcycle and the pilot can handle all required maintenance. Maintenance required consists of periodic tire, brake and battery inspection and replacement. The engine requires a $300 overhaul after every 25 hours of flight time (to be performed by the engine manufacturer; about a 2 week job).
Training
The J103 is designed to be exceptionally easy to fly. The jet engine provides linear thrust such that there are no yaw-inducing torque effects as is the case with propeller driven aircraft. The engine is mounted such that the thrust is in line with the center of drag, so that changes in engine thrust and airspeed do not induce any pitching moments. Stall speeds are low and no flare is required to dump energy at touchdown – just fly close to the landing zone and cut power – it will sink naturally and land. Pilots should achieve basic proficiency with perhaps 10 hours of flight training.
Project Status - As of December 2024
Since the project initiation in summer of 2023, we have made two mockups in wood with which we've figured out the dimensions and ergonomics and confirmed some other design mechanics, and then we built a functional wingless prototype in aluminum with which we've performed some taxi testing. We are now building the final flyable prototype using the waterjet cut ultra strength steel. See latest photos below. What you see is currently weighing in at 79 lbs. Next up is to add the brakes and the fuel system and then get back to taxi testing!
The J103 in transport configuration with the tail folded over. Ready to roll!
Project Milestones
-
Commence taxi testing of final design by end of Q4 2024
-
Commence flight testing by end of Q1 2025
-
Solicit public feedback at the Sun-N-Fun airshow April 1-6 2025 in Lakeland, Florida
-
Complete all EAA FTM flight testing by end of Q2 2025
-
Show the final design at the EAA AirVenture airshow July 21-27 2025 in Osh Kosh, Wisconsin.
​
To stay up to date on the latest progress of Project J103, follow us on X (Twitter) @KestrelAeros.
​
Interested in the J103, or possibly becoming a beta tester or early adopter? Email us at info@kestrelaerospace.com.
Future Variants:
-
Propeller Driven. Several small 2 cycle and 4 cycle engines are available which would be suitable for the J103 ultralight. The propeller version of the J103, the K103TM, would be a bit heavier but would be significantly more fuel efficient and allow for hours of flight time.
-
Light Sport Aircraft. The J103 and K103 are being designed from the start to handle more powerful engines and have a greater fuel capacity which would significantly increase top speed and range. This would take it outside of the Part 103 regulations and require it to be registered as a Light Sport experimental aircraft with the FAA, but for those who have a pilot license it would allow for a higher performance aircraft which retains the many advantages of the ultralight design.
-
Search and Rescue. The Kestrel LSATM may be an ideal aircraft for search and rescue, having greater range with much less operating cost and training time required than a helicopter. A possible multi-engine variant would be particularly well suited for over-water operations in search of missing boats or downed pilots, which can then be rescued by surface vessels or other aircraft. Kestrel Aerospace will be pursuing SBIR funding with the U.S. Air Force, Navy, and/or Coast Guard to further explore these opportunities.