Horizon Aircraft CEO Talks Hybrid-Electric VTOL Design

Horizon Aircraft’s Cavorite X5 is a hybrid-electric aircraft with a patented fan-in-wing vertical lift system that enables vertical take-off and landing (VTOL) capabilities. Its maximum speed will be about 280 miles per hour, and it is expected to have a range of roughly 500 miles. The VTOL aircraft will target multiple applications and will initially have a five-passenger capacity.

Horizon was one of 11 companies to complete a Phase I contract award from the U.S. Air Force’s AFWERX program this year. The market research program challenged applicants to design a high-speed VTOL aircraft concept and received about 230 submissions. Bell Textron, Jaunt Air Mobility, Whisper, and Jetoptera were some of the other companies to receive a Phase I contract award. Completing the Phase I contract on June 30 allowed the Horizon team to accelerate development of the Cavorite X5 prototype.

The nine-month-long Phase II contract will be starting this fall and will offer companies significant non-dilutive financing to support further research and development of high-speed VTOL aircraft. Following that, Phase III of the AFWERX challenge will finance a 30-month program in which a functional full-scale prototype will be developed.

E. Brandon Robinson, CEO of Horizon Aircraft, joined Avionics International for a question-and-answer session about developing their hybrid-electric VTOL and the company’s long-term goals.

Avionics: How has your previous experience—and the team’s experience—informed decisions related to the design of Horizon’s VTOL?

Robinson: Most of us have significant operational experience and have had to deal with bad weather and many other unforeseen circumstances. I was in the RCAF [Royal Canadian Air Force] for 22 years, and I spent the majority of that flying CF-18s. My father is a pilot, and our chief composites engineer is also a pilot who has designed, built, and flown his own aircraft from clean sheet design.

We have a lot of practical aviation experience. That gave us a head start for designing an operationally tough aircraft—one we would be happy to put our kids in the backseat of.

That’s why our machine flies the majority of its mission looking and acting exactly like a normal aircraft. Once the wings close on our Cavorite X5, it’s flying in a configuration exactly like a normal aircraft. If you have to take off or land at a normal airport, you can do so. And from a regulatory perspective, we’re starting in a pretty comfortable place for the folks certifying the aircraft for commercial operations.

Avionics: What is the team currently working on?

Robinson: We recently completed the assembly of our 50% scale prototype Cavorite X5 aircraft. It has a 22-foot wingspan, is 15 feet long, and weighs about 500 pounds. We’re undergoing flight testing of that aircraft right now.

We are currently conducting tethered hover testing: teaching the airplane how to control itself and maintain a stable hover. Essentially, it has enough muscle and agility; we just need to tune the flight control parameters so that it can maintain stability.

This testing has been going extremely well. In fact, we will be moving on to transitional flight testing—where the aircraft moves from hover to fly forward in transition to normal wing-borne flight—in the next few months.

Avionics: How will Horizon’s aircraft fit into the business and commercial aviation sectors?

Robinson: Any portion of the business aviation world where vertical take-off and landing capability is important—getting in and out of confined locations where there is not typical runway infrastructure—our aircraft will be disruptive. It can take off and land vertically like a helicopter, but go twice the speed, and its operational costs are also significantly lower. That’s a very disruptive model.

Avionics: Can you share any details about the avionics that will go into the Cavorite X5?

Robinson: For the 50% scale prototype that we’re currently flight testing, the avionics are mostly in-house. All of the systems are commercial off-the-shelf but are highly modified by our team. We will be looking to partner with other companies for the full-scale prototype. We already have some relationships in place—for example, with Honeywell Aerospace. They make a great fly-by-wire system, and they’re very forward-looking into the eVTOL world. The Honeywell HTS900 hybrid power system is an option to power our full-scale aircraft. Honeywell has been doing exceptional work in the VTOL space and we are excited to see how their innovative products could strengthen our aircraft.

Avionics: What applications is Horizon’s VTOL designed for?

Robinson: Our aircraft will initially be more useful in the regional air mobility market—at ranges of 50 to 500 miles. Typical missions in the short-term will be disaster relief and emergency services: medevac, organ transplant, and emergency medical supply, those sorts of things that require vertical take-off and landing flexibility at faster speeds than a helicopter while maintaining lower manufacturing costs.

Avionics: Why is the Cavorite X5 designed to be hybrid-electric rather than fully electric?

Robinson: The simple reason is that gas still has about 20 times the energy density of the best batteries. We wanted enough fuel reserve to meet all of the regulatory requirements, but we also wanted an airplane that could fly fast, have significant operational range, and carry enough payload to

Avionics: In what ways do you expect Horizon Aircraft to grow and evolve in the next five to ten years?

Robinson: I think people tend to overestimate what can be accomplished in the short term and dramatically underestimate what can be accomplished in the long term.

In 5 years, Horizon Aircraft will be through certification and into low-volume production of our unique aircraft. The Cavorite X5 will be saving lives in medevac, organ delivery, and disaster relief missions, as well as exploring initial use cases for remote resupply and regional passenger transport. We will also continue exploring ways in which to serve military capability—helping service people to conduct critical missions around the world.

In 10 years, we will be a major manufacturer of high-speed VTOL aircraft. We will continue to innovate, and I’m sure right now I will dramatically underestimate the success of companies that continue to innovate, have deep operational experience, and keep the end user as a primary focal point for building an aircraft that just makes sense.