eSTOL aircraft developer Metro Hop has been given the green light from the U.S Air Force’s Agility Prime program to test its patent pending Active Landing Gear™, which will allow its aircraft to fly up to 250mph while carrying substantial payloads.

Thanks to a Phase I Small Business Technology Transfer award contract, Metro Hop is teaming up with Auburn University’s Vehicle Systems, Dynamics, and Design Lab (VSDDL) to model and validate the design of the Active Landing Gear. VSDDL, alongside its director Dr. Imon Chakraborty, will then use its flight simulation facilities and software to model the gear under various conditions during the takeoff and landing phases of flight.

Speaking to eVTOL Insights, Metro Hop’s CEO and Founder, Bruno Mombrinie, gave an update on the company’s work so far. He said: “We’re in the process of building a virtual aircraft and the software we’re using to model the behaviour is extremely sophisticated; I was really surprised by its capabilities.

“The simulation software has come a long way since I was doing this and it’s pretty amazing what we can realistically simulate. And we think this will be a lot better than a scale model. We’ll have real values, be able to make adjustments and improve a lot of the design just from the the simulation.

“We can simulate turbulence in the air, never mind all the parameters of the aircraft but we can also simulate the environment very accurately. And then of course, the data from the real aircraft can just be plugged into the model to get even better numbers. We’ve got a lot of support from Auburn University. At least four students are working on it there and the professor’s really involved also so it’s a great effort and it’s pushing us to do more. I’ve actually actually been able to do some engineering work myself!”

The Vehicle Systems, Dynamics, and Design Laboratory (VSDDL) at Auburn University has extensive experience in modelling and simulation of aircraft dynamics and systems, flight simulation, and aircraft sizing and performance analysis.

The lab is supported by funding from NASA Langley and Ames Research centers to investigate stability and control for novel aircraft concepts. It is also involved in multiple projects with SBC (small business concern) partners as part of the Agility Prime program.  

Dr Chakraborty, who is also assistant professor in the Department of Aerospace Engineering at Auburn University, said: “The VSDDL recently developed a reconfigurable flight simulator aimed at novel aircraft configurations and we’re currently developing two more.

“We look forward to using our capabilities to give us precise measurements of Metro Hop’s flight capabilities and allow us to aggregate essential data on the plane.”

After this initial phase of testing is completed, Metro Hop will move forward with construction of a fully operational landing gear set and begin dynamic landing-drop and taxi testing.

Talking about the work that will be carried out as part of the Agility Prime contract, Mombrinie said: “Our aircraft flies like a normal plane. But coming into the approach and landing, and the same with the ground roll and take off, those are things that are going to be a little bit different in our aircraft. So being able to realistically model that and know what’s going to happen and how it affects the performance is huge.

“This software is then integrated with a virtual simulator, so then we can actually seen on a simulator what’s happening. As I said, it’s better than building a model in the sense that in a few weeks, we can build a machine. Of course, it’s on a computer but it’s a very realistic simulation and we can investigate what happens, play it back and so on.

“With a real machine, you’d be hard pressed to know what exactly happened and you’d have to go try it again. And if it was something that didn’t work well you might not want to go try it again.”

Mombrinie added that the project, which will last until the end of summer, will enable Metro Hop to present the data it finds in videos and use them to contribute towards fundraising efforts.

“We’ll be able to show what our aircraft can do and in a kind of a realistic way. It’s just not playing a video game with some neat pictures”, he said. “This is actually how the thing behaves. And it also advances the next step of the detailed engineering that’s involved in a big way.

“We’re not just detailing what we think or what we can calculate from a few rough calculations, we’re actually seeing the whole behaviour. The first aeroplane we’re going to build will be very close to the final thing; we’re not going to waste time making adjustments on the real one as will we will do it on the virtual machine. When getting certification from the FAA and EASA, you have to fly some real missions, take the points and interpolate them with the computer simulation because that it’s that good. That could help significantly reduce the time it takes to get certification for example.”

Many companies in the industry like Metro Hop has have also benefited from Agility Prime contracts to further the development of their programmes. Examples include Airmap, Elroy Air and Jump Aero.

And Mombrinie has spoken highly of the programme and the opportunity it gives for companies wanting to further accelerate their projects.

“It gives companies the ability to have contracts with other government agencies and they have a very good outreach programme with question and answer sessions. They’ve been really helpful and I’m appreciative of everything they’ve done so far.”

eVTOL Insights spoke to Mombrinie as part of its popular series of podcasts, where he talked more about the company’s eSTOL aircraft and vision. It’s mid-mile delivery service is structured around a simple aircraft with the pending Active Landing Gear™ system that is designed to operate in urban areas.

Metro Hop says its aircraft’s speed increases productivity and offers a competitive edge, allowing for smaller and more efficient runs. Additionally, its aircraft is supported by robotically loaded cargo bins and hot-swapped battery pods at dedicated MetroDocks™.