Take 15 people. Add a country shed. Find inspiration in a 130-year-old Aussie invention. Then build a viable electric-hydrogen air ambulance.
The 15 employees work with the husband-and-wife team running Australian aerospace company AMSL Aero.
The country shed is a hangar at an Aerodrome Industrial Park at Narromine, 400km northwest of Sydney.
The inspiration is the box kite inventor Lawrence Hargrave used in 1893 to lift himself into the sky above Stanwell Park, NSW. He later developed a three-cylinder rotary engine that kicked off an aeronautical engineering race that lasted half a century.
The eVTOL (hydrogen-electric vertical take-off and landing aircraft) is called the Vertiia.
It’s just won a $5.43 million development grant from the Federal Government’s Australian Renewable Energy Agency (ARENA). And today, AMSL Aero signed an order and received deposits for 10 Vertiiaaircraft, with an option for 10 more, from its first civil customer Aviation Logistics.
A battery-electric version of the aircraft successfully completed its maiden test flight – while tethered to the ground by restraining ropes and control lines – early last year. Inventor Andrew Moore says the remote-controlled hover was the first step in proving the design’s potential.
“As Vertiia lifted off, we felt the same rush of adrenaline that Lawrence Hargrave must have felt nearly 130 years ago,” Moore, the CEO of AMSL Aero, says. “The prototype flew better than we expected. It was remarkably smooth and a delight to fly.”
But test flights are just one step in the long journey towards earning Civil Aviation and Safety Authority (CASA) certification. AMSL hopes to have commercial models rolling off a production line by 2026.
Balancing act
Moore says that Hargrave’s box kite is at the heart of the Vertiia’s design.
It’s light. It’s compact. It’s strong.
The shape has the same lift as a conventional wing in half the span and considerably less structural weight. And this cascades into lighter-weight engines, the need for less battery space, and so on, says Moore: “The combination of its unique aerodynamic and structural design means it travels further using less energy.”
The outcome is what he calls the “world’s most efficient electric VTOL aircraft.”
The initial all-electric prototype was intended to carry a pilot and four passengers at a cruising speed of 300 km/h over a distance of 250 km before needing to recharge its batteries.
But the design allowed for the addition of a supplementary hydrogen fuel cell system to boost the flight distance to about 1000 km. This is the model that has won the interest of ARENA. AMSL will use the money to build a new prototype.
The Vertiia eVTOL’s ungainly appearance also conceals what AMSL hopes will prove to be a series of advantages over conventional helicopter designs.
One is the simple fact that it has eight independent “off-the-shelf” Slovenian-built engines, each with its own lifting blade. Moore says this eliminates the “single point of failure” risk common to helicopters as the distributed electric propulsion system can compensate for various failures to allow a safe landing.
Old problems, new answers
AMSL moved to Narromine in 2020 after winning a $950,000 grant from the New South Wales Regional Investment Attraction program. It had a proof-of-concept airframe and tilt-motor system completed by the end of the year. Scale model testbeds were operating in 2022.
Interest from emergency medical service helicopter operator Careflight and the Australian Defence Force saw it shift its initial focus away from producing an “air taxi” towards an emergency evacuation platform.
The company says this is reflected in the emphasis on ease of access for passengers to the Vertiia’s cabin, which can be configured to carry one patient and three medical personnel.
The ultimate goal is to produce a low-cost emergency air-lift vehicle with what the designers say will be maintenance costs comparable to any road ambulance.
“Unlike aeromedical aeroplanes that require a runway, Vertiia will carry patients directly from any location straight to the hospital, significantly reducing the complexity and time often required to transport vulnerable patients,” says AMSL Co-Founder Siobhan Lyndon. “It’s not only safe and quiet but it was also developed for the harsh long-distance conditions in Australia. If it can work in Australia, it can work anywhere.”
AMSL initially attracted about $10.8 million in funding from the Federal and NSW governments. This was followed in 2022 with a $23 million investor fundraising effort.
“The significant funding provided by ARENA will mean that we can accelerate the design, build and certification activities,” says Moore.
Cool technology
Driving the Vertiia eVTOL project is the fact that the aviation sector contributes roughly 2.5 per cent of global greenhouse gas emissions. And about one-fifth of this comes from short-haul regional flights of under 1000km.
But replacing the flexibility and energy density of fossil-based aviation fuels poses a significant challenge.
Hydrogen-electric power cells are emerging as the most viable alternative for smaller aircraft
Biofuel ethanol promises easy integration with existing aviation infrastructure and engines. But the enormous scale of production – including everything from palm oil and Camelina to waste oils synthesis and algae reactors – threatens to seriously impact the agricultural food industry.
Electric motors are much smaller and lighter than their fuel-driven counterparts, but batteries are heavy. And even the most energy-dense options available take up considerable space.
Hydrogen combustion has powerful potential, and burning the gas simply produces heat and steam. But, at room temperature, the gas is very voluminous – with the energy equivalent of a car’s fuel tank taking up the space of a cement-truck’s mixing container. And compressing it requires heavy tanks or sustained cryogenic freezing at -253C.
Major aircraft manufacturers believe this may be an answer for large, long-haul airliners. Airbus hopes to have a working hydrogen-powered jet engine by 2026.
Hydrogen-electric power cells are emerging as the most viable alternative for smaller aircraft. Here, hydrogen is fed into a negative electrode cell (or anode), and air into the positive (cathode). A catalyst prompts the hydrogen atoms to break down, sending protons to the cathode to unite with oxygen and create wastewater. The electrons are drawn to the anode and formed into an electrical current.
This simple process is reliable. And it allows a small aircraft to balance the advantages and disadvantages of batteries and hydrogen gas against each other.