How e-planes work varies upon design. Some are more like slow-moving drones or expensive helicopters. Others behave like planes, which make them better suited for longer ranges than urban transport.
German startup Volocopter and China’s EHang, for instance, are building air taxis that are essentially large multicopter drones capable of carrying human payloads. Multicopters are slow-moving compared to planes, which is a good thing in an urban setting where they have to descend after a short run.
The problem is that their multiple sets of rotating blades guzzle power just to keep the drone-like air taxis in the air. This limits their range because the batteries would get too heavy otherwise. So, they need frequent recharging.
Then there are e-planes that use wings to take off, fly and land. These need to fly fast enough for the airflow to lift them and keep them aloft. The more compact the wings, the faster they have to fly. What it means is that by design they become inefficient if forced to cover short distances in cities.
That’s one reason why German startup Lilium, which has tested a five-seater e-plane, positions itself as a regional air mobility operator, providing services to nearby towns and cities rather than within cities. It is building a ‘vertiport’ in Orlando, Florida, in the US for the so-called eVTOL (electric vertical take-off and landing) aircraft. European cities too typically have clusters of small cities within a radius of 100-200km that can be served by eVTOLs.
While Lilium has well-known investors like Tesla’s second-biggest shareholder, Baillie Gifford, its main rival, California-based Joby Aviation, is going public through a merger with a special purpose acquisition company of LinkedIn co-founder Reid Hoffman and Zynga founder Mark Pincus. Joby got backing from Toyota last year in a $590 million funding round and acquired Uber Elevate, an air taxi venture of the ride-sharing firm.
Despite the huge backing for ventures like these in the US, Europe and China, there’s room for innovation by smaller startups like The ePlane Company incubated in IIT Madras. Until e-planes come into the market, nobody can be sure what’s economically viable for different market segments.
“We have a potentially better product-market fit when compared with the technologies developed so far,” says Satya Chakravarthy, aerospace engineering professor at IIT Madras and co-founder of The ePlane Company.
The Indian startup’s two-seater e-plane is designed for aerial urban mobility, that is, short-range intracity flights. It will take off from rooftops or parking lots without requiring ‘vertiports’ like Lilium’s five-seater e-planes.
The Indian e-plane has a hybrid design that uses both rotors and wings. The rotors are for take-off and landing, while the wings are for flying fast. To borrow a line used to describe boxer Muhammad Ali, it “floats like a butterfly and stings like a bee”. More technically, it takes on board the advantages of drones and planes, while jettisoning their drawbacks. It’s fast enough for far less battery usage than a full-fledged electric multicopter like that of Volocopter. And yet, it’s slow and small enough for intracity flights.
“We are targeting a speed of 180-200kmph, which would be between that of Volocopter and Lilium e-planes,” says Chakravarthy. “We also want to keep it very compact so that it comes close to being a door-to-door service.”
A subscale prototype is set for a trial flight in a month or two. That will demonstrate the design innovation, enabling it to fly slower than what e-planes with compact wings would normally require.
“That’s counter-intuitive to an aerospace engineer, but we have thought through the flow field around the e-plane to get the required aero propulsion integrated performance,” says Chakravarthy, without going into detail on ePlane’s main intellectual property (IP) for this business use case.
The startup raised seed funding late last year to develop its IP and prototype. A larger funding round is on the anvil as it comes closer to trials. It aims to keep the cost of the e-plane below ₹1 crore, which would make it similar in price to a premium Range Rover or quarter the cost of the cheapest helicopter. But more than luxury car or helicopter services, ePlane wants to be an Uber for the skies. “An Uber ride between the airport and Electronic City in Bengaluru costs anywhere between ₹1,500 and ₹2,500 depending on the time of day. To start with, we are targeting 2x the price of an Uber ride for a 10x drop in travel time,” says Chakravarthy.
How the pricing pans out will depend on regulations. For example, one of the seats would be occupied by a pilot until regulators allow autonomous flights to carry passengers. But human-piloted e-plane flights would be cheaper in India compared to the West, which would make it feasible for an operator to break even within two years, taking into account the capital expenditure and operating expenses, he says.
Regulations will vary from one country and city to another for testing e-planes and actual deployment as well. For example, Dubai and Singapore are among the most proactive in engaging with e-plane makers. Volocopter has already done test flights in these cities and hopes to launch commercial services soon.
The Indian startup may have to do its trials in remote areas in the country, depending on what regulators say. But once the technology is demonstrated, it will go wherever the environment is suitable for testing and deploying passenger flights. “Ideally, we would want to fly in India but we don’t know how long the certification process will be,” says Chakravarthy.
Chakravarthy has been a mentor to several startups over the years, providing them with guidance as well as access to lab facilities at IIT Madras. But he wanted to walk the walk, and not just talk the talk. “It’s far easier to evangelize deep tech startups than to actually plod through one. I wanted to see how to run a startup,” he says. That’s how he became a co-founder of ePlane with Pranjal Mehta, who graduated from IIT Madras in 2019. Chakravarthy stopped teaching last year and started cutting back on his research guidance to focus on the startup where he is the CTO and a major shareholder, thus putting skin in the game.
A professor-student duo from a top engineering college launching a futuristic startup would be the done thing in Silicon Valley. But it’s far less common in India where professors appear to be a lot more risk-averse. Chakravarthy is flying into uncharted skies.
Malavika Velayanikal is a consulting editor with Mint. She tweets @vmalu