“Living in a city with odious traffic is very tiring, especially for students who have to travel for hours to reach school or coaching. As a dweller of Bangalore, it has been a personal problem to me and is wished to be solved in one way or the other if given a chance. Sometimes, you wish you could just fly over the traffic"
shares Pranjal Mehta, the CEO of The ePlane Company, as he talks about what inspired him to make a pioneering effort towards electric air mobility in India. During his days at IIT Madras, Pranjal was introduced to Professor Satya Chakravarthy of the Aerospace department in IITM, who was working on electric planes. The two decided to form The ePlane Company, a startup, to realise the dream of flying over the traffic in crowded cities. Recently, the project gained pace as it raised a seed fund of 1 million USD from investors Naval Ravikant and Speciale Invest.
The ePlane Company was founded in April 2017 and launched in 2019. They have designed an electric aircraft that can take off and land vertically and, therefore, be used for intra-city commute. These taxis will travel at a top speed of 200 kilometers per hour and make ten to twenty trips per charge, covering a total of 200 kilometers. A trip in it may cost one and a half to two times that of a regular taxi, but its advantage is that it will bypass traffic and reach the destination much faster. We can also expect its cost to decrease to that of any app-based taxi service once they become more common. The battery-powered taxi will have a payload capacity of 200kg to accommodate a passenger and a pilot. The ePlane Company will begin testing a scaled-down prototype of 50kg payload capacity in July 2021. They plan to get the required certification by mid-2024, which is when the first ePlane is expected to start commercial operations.
Why go Electric?
In many parts of the world, the conventional aircraft used for commute is a helicopter taxi. People use them to fly from home to work and to fly to the airport. Being their main substitute, electric air taxis can be compared to helicopters.
Helicopters have very high purchase and operating costs, one of the main reasons for which is their complex powertrain. This increases the overall asset cost. On the contrary, electric vehicles have a very simple powertrain. They consist of only motors, blades, wires and a power source. The power from the batteries is easily distributed to the motors, allowing it to have a very facile mechanism. Due to these reasons, the asset cost of an electric vehicle is lower than that of an equivalent combustion vehicle.
Moving to operation costs, there are three primary expenses to a helicopter: fuel, maintenance, and pilot fees. The ePlane is designed such that the per kilometre cost of electricity consumed by it is less than that of fuel for a helicopter. Helicopters require far more maintenance, too, owing to the oiling and greasing needed for their complex powertrains. Electric powertrains, by contrast, require very little maintenance. Furthermore, while ePlanes will be piloted in the beginning, the company has a very clear roadmap to achieve autonomous flight in the future. This would eliminate the cost of having a pilot too, bringing the operating cost of an ePlane to one-tenth that of a helicopter.
This lower cost and the reduced environmental impact motivated Prof. Satya and Pranjal to design an electric aircraft.
How to Design a Flying Taxi
After conceptualizing what the aircraft should be capable of by studying the market and understanding the use cases, Pranjal consults his co-founder, Prof. Satya, who realises the tech capable of doing it. With the help of numerous calculations and simulations, the engineers of the ePlane Company then iteratively converge on a design for each part of the plane. According to Pranjal, this is where Prof. Satya’s twenty-four years of experience have been very beneficial.
"As a founder, Prof. Satya is awesome because he has a very good sense of business and the market. He is not trying to build the fastest flying taxi. The idea is, let’s build something that solves the user’s problem"
This, Pranjal goes on to say, is a very simple yet essential understanding that is needed while designing any machine. One must refrain from going overboard with extra features and only stick to what the consumer needs. This understanding, Prof. Satya’s hardworking nature and vast technical expertise have been incredibly beneficial to the startup.
One of the main challenges with electric vehicles, and a significant factor that has held back their development, is the low energy density of batteries. This means that a certain mass of petrol contains much more energy than a battery of equal mass, which is why an electric vehicle should have a lot of weight in the form of batteries added to it to achieve the performance of a combustion vehicle. This problem is amplified while designing an aircraft, where weight is a much greater concern and is the primary reason large electric planes that can replace commercial airliners have not been designed yet. Pranjal presented a very counter-intuitive yet interesting fact when asked about how the design gets around this problem.
“Contrary to what you might think, once you’ve taken off, flying is more energy-efficient than driving on the road. I only incur drag when I fly and don’t have to deal with the friction of the road. Also, when you are on the ground, a lot of energy is lost while braking, whereas when you are in a plane, you don’t have to brake. This is why, if I compare a Tesla and an ePlane over a twenty- kilometre trip, they consume similar amounts of energy- which is a surprising fact for many to learn.”
Due to this and the fact that the ePlane is designed for short intra-city trips, the battery pack that powers it is light enough to be feasible for use.
All about the ePlane
“In terms of access, we wanted to make the experience very similar to a car,” says Pranjal, as he talks about the goals the company set before designing the vehicle. Like a car, the user should be able to access it from very close to their home and travel door to door conveniently. Another goal was to fly short distances in cities efficiently. The final design checked all these boxes, with the capability to take off and land from rooftops!
Since the vehicle would have to operate from rooftops and helipads, it was evident from the start that it would need to take off and land vertically, like a helicopter. However, the main drawback of designing a mere ‘electric helicopter’ was that energy would have to be spent only to keep the craft in the air. Having wings to generate lift that keeps the vehicle in the air as it moves forward would be far more efficient.
Keeping these points in mind, The ePlane Company designed a unique aircraft that takes off like a helicopter and flies like a plane. They accomplished this using two sets of rotors- one vertically oriented for take-off and landing and the other horizontally oriented, for use during flight. Another popular mechanism that can be used to achieve this effect is to have a single set of vertical rotors that tilts ninety degrees during horizontal flight. This is an approach used by Lilium, a German company that is also working on an electric air taxi. The engineers at The ePlane Company decided not to implement this since, as put by Pranjal,
"We know that tilting parts means a risk that its mechanism might not work and that means that the regulator is going to ask you to make that system foolproof, with a lot of redundancies, which means more cost of development and longer certification times.”
The challenge, however, does not end there. Since the lift produced by a wing depends on its length, flying a plane at low speeds- the range safe for flight in cities would require it to have an enormous wingspan. This was something The ePlane Company could not afford since intra-city flight needs a compact form factor. While other electric air mobility companies like Volocopter and Lilium have not been able to get around this problem, the engineers at The ePlane Company were the first in the world to solve it. They developed an ingenious system that enables them to fly slow, keeping the wingspan compact. Pranjal could not divulge its details since this ‘secret sauce’ that differentiates the aircraft from its competitors is Intellectual Property.
The engineers have planned sophisticated software to guide the aircraft when the ePlane starts undertaking autonomous flights. Interestingly, Pranjal notes, the algorithm for a pilotless plane is simpler than that of a driverless car. This is because cars have a lot more obstacles to take into account along with other things, like staying in the correct lane and following the best route to its destination. The ePlane, on the other hand, relies on a simple obstacle detection and avoidance system. When one of the aircraft’s many sensors detect an obstacle in its path, it feeds the information to an onboard computer which carries out actions to avoid the obstacle.
The Road Ahead
While ePlanes are designed to be piloted from day one, the company has plans to make them fly autonomously in the future. When asked about what has been planned to instill trust in someone flying in a pilotless plane, Pranjal said that the idea is to first build trust in the fact that this vehicle works, by flying the piloted version and by flying cargo autonomously. Moreover, the trust in driverless vehicles is being strengthened as companies like Tesla successfully release autonomous ground vehicles. Apart from this, all components that may fail have been made redundant. The aircraft has multiple rotors and batteries so that the others can take over in the unlikely event of the failure of one. Pranjal also talked about something that he calls an escalator problem:
“My grandmother is scared to take the escalator, it is a technology that works just fine but she is scared to take it because she hasn't seen it perform. On the other hand, I am very happy to take it as I grew up seeing these things. What's interesting about technology adoption is that if kids and youngsters think that they want to do it, they are very happy to do it. We have already seen people sitting in autonomous cars and there will always be a part of the population that will be okay sitting in autonomous planes. Initially, the ones comfortable will fly and that will build the trust for others if there will be no mishaps, and over time the adoption will take place.”
When asked whether the Indian market is ready for such a product, Pranjal said that it would definitely be, given the traffic problem in many Indian cities. Indian customers are trying to use alternatives to road transport when available, which makes the market conditions here very suitable for a flying taxi. This readiness of the market would, however inevitably attract international players in urban air mobility, like Lilium and Volocopter. Pranjal believes that his company is ready for this because they know the Indian market best. Since the ePlane Company’s research and development is carried out in India, their cost will be lower than that of their competitors. Also, the ePlane Company has designed a product much more suitable to the Indian environment. The product- the taxi is also more compact than their competitors', which gives them the upper hand. Furthermore, with the Indian government actively taking steps to increase the adoption of Electric vehicles, the future of the ePlane company looks bright. While the ePlane is radically different from a ground vehicle in terms of operation, Pranjal believes that they can definitely benefit from charging infrastructure and other amenities that come up for electric cars.
This small team of fifteen engineers has a lot in store for the future of mobility in India. With the world slowly but surely going electric, the ePlane company is one of the many startups taking significant steps to pave the way. It will not be long before flying taxis become mainstream, and the view out of one’s window starts looking like a scene from a science fiction movie!