the Celera uses an astonishing 80% less fuel than a comparably sized jet
Otto Aviation
Remarkable World’s Most Efficient Passenger Plane gets Hydrogen Powertrain!
The Celera 500L is a truly remarkable design. Otto Aviation says its odd shape delivers an astonishing 59 percent reduction in drag. This is a massive leap in efficiency and range compared to traditional plane geometries. Arguably, this thing should’ve been electric from the get-go. So, it’s a no-brainer that Otto has teamed up with ZeroAvia to build a version with a hydrogen fuel cell powertrain.
Otto claims the Celera 500L in standard fossil fuel-propelled form is “the most fuel-efficient, commercially viable business aircraft in the world”. Its “flying suppository” shape might not win it any fashion awards however. But if true beauty lies in perfect function, then this thing could be a bulbous supermodel.
Designed for Laminar Flow
The whole thing is designed to maximize laminar flow. Smooth layers of airflow with little to no mixing of adjacent layers moving at different speeds. This avoids the swirls and eddies that lead to air turbulence at speed, causing aerodynamic drag and wasted energy. Laminar flow is by no means a new concept, but Otto says it’s pushed the idea so far forward. The Celera design that it uses 80 percent less fuel than a traditional design. No, that’s not a typo.
passenger aircraft design by a country mile.
Otto Aviation
A Monster Efficiency Factor
The Celera flies on an efficient 550-horsepower combustion engine. Otto claims it will fly six passengers up to 4,500 nautical miles (8,334 km) at cruise speeds over 460 mph (740 km/h). These figures challenge small business jets for top speed while more than doubling their range. An impressive glide ratio of 22:1 allows pilots to switch off the engine altogether and glide for up to 120 miles (200 km) completely unpowered. This monster efficiency factor, says Otto, should make the Celera some 5-7 times cheaper to run than a comparable jet.
Mind you, it wont scale up to full-size airliner size, since the low-drag laminar flow model relies on a width-to-length ratio that’d be impractical in a bigger bird. But Otto says it’ll scale up to take 19 passengers. There are plenty of markets that could make use of an efficient airframe in the 6-19 passenger space.
A Full-Scale Prototype
It’s not a pie-in-the-sky render, either. Otto has built a full-scale prototype. And by November last year the company announced it had completed 55 successful test flights. These flights reaching speeds over 250 mph (400 km/h) and altitudes up to 15,000 f. He added that “all test flights have validated the aircraft’s operating performance goals”.
Now clearly, an 80 percent reduction in fossil fuel use is an environmental win in and of itself. But there’s one sector in aviation that’s crying out for brain-busting efficiency figures like the Celera promises. That is the emerging zero-emissions sector, which is currently struggling. Poor range figures thanks to the low energy density of lithium batteries are a constant problem..
A Fuel Cell-Electric Powertrain
When we first wrote about the Celera 500L in 2020, many questioned why this thing wasn’t electric. And it seems Otto is on board with the idea. It’s now announced a collaboration with hydrogen aviation pioneers ZeroAvia to develop a fuel cell-electric powertrain, specific to the Celera’s requirements.
This airframe’s bulbous shape works well with a hydrogen concept. Hydrogen powertrains can weigh much less than battery-electric ones, but they tend to take up a bit of space. Still, ZeroAvia is being relatively humble with its ambitions to begin with. It is aiming for a range of just 1,000 nautical miles (1,852 km) of zero-emissions range for a hydrogen-fueled Celera. Still, that’s a very useful distance, and pretty extraordinary for a clean electric passenger plane.
Otto Aviation
ZeroAvia is champing at the bit; this could be the company’s first chance to work on a brand-new aircraft design. “The majority of our commercial deals to date,” says founder and CEO Val Miftakhov in a press release, “have focused on retrofit and line-fit for existing airframes, which is essential to deliver zero-emission flight to market as quickly as possible. However, efficiency gains from new airframe design can expand the impact of zero-emission aviation. We are pleased to collaborate with innovators like Otto Aviation. We aim to bring cutting-edge clean sheet designs to market as we can optimize the hydrogen-electric propulsion system for those designs.”
The Downside of New Airframes
Of course, there’s a downside to working on brand-new airframes too. It’s one thing to build a prototype and do flight testing, and another altogether to get an aircraft certified. And get it ready for volume production – particularly one that deviates from the norm.
Otto has made remarkable progress thus far. If the company’s efficiency claims are true – and will remain a hotly debated topic on aviation forums. Otto needs to put extraordinary proof beside its extraordinary claims. This does feel like an important aircraft that the world needs right now. Even the fossil-fueled version could be exceptionally useful for passenger and cargo operations. This could make a significant contribution to decarbonization.
But the next steps will be a huge challenge, requiring a ton of long-horizon investment. We hope Otto’s team is fortified and ready for the grind ahead. All jokes aside, we wish them all the best. We’d hate to see this flying suppository get shelved.
Source: ZeroAvia / Otto Aviation
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