In late 2019, after years of studying aviation and aerospace engineering, Hector (Haofeng) Xu decided to learn how to fly helicopters. At the time, he was pursuing his PhD at MIT's Department of Aeronautics and Astronautics, so he was familiar with the risks associated with flying small aircraft. But something about being in the cabin gave Xu a greater appreciation for those risks. After a couple of stressful experiences, he was inspired to make helicopter flights safer.
In 2021, he founded the autonomous helicopter company Rotor Technologies, Inc.
It turns out that Xu's near misses weren't all that unique. Although large commercial passenger aircraft are extremely safe, people die every year on small private aircraft in the U.S. Many of those deaths occur during helicopter flights for activities such as crop dusting, firefighting, and medical evacuations.
Rotor is retrofitting existing helicopters with a suite of sensors and software to remove the pilot from some of the most dangerous flights and expand use cases for aviation more broadly.
“People don't realize that pilots risk their lives every day in the United States,” Xu explains. “Pilots crash into cables, become disoriented in adverse weather conditions or lose control, and almost all of these accidents can be prevented with automation. “We are starting by targeting the most dangerous missions.”
Rotor's autonomous machines can fly faster and longer and carry heavier payloads than battery-powered drones, and by working with a reliable helicopter model that's been around for decades, the company has been able to get to market quickly. Rotor's autonomous aircraft are already taking to the skies around its headquarters in Nashua, New Hampshire, for demonstration flights, and customers will be able to purchase them later this year.
“A lot of other companies are trying to build new vehicles with a lot of new technologies around things like materials and powertrains,” says Ben Frank '14, Rotor's chief commercial officer. “They are trying to do everything. We're really focused on autonomy. “That's what we specialize in and what we think will make the biggest change in making vertical flight much safer and more accessible.”
Building a team at MIT
As a student at the University of Cambridge, Xu participated in the Cambridge-MIT Exchange Program (CME). His year at MIT apparently went well: after graduating from Cambridge, he spent the next eight years at the Institute, first as a PhD student, then as a postdoc, and finally as a research associate in MIT's Department of Aeronautics and Astronautics (AeroAstro). , a position he still holds today. During the CME program and his postdoc, Xu was mentored by Professor Steven Barrett, who is now the director of AeroAstro. Xu says Barrett has played an important role in guiding him throughout his career.
“Rotor's technology didn't come out of MIT labs, but MIT really shaped my view of technology and the future of aviation,” Xu says.
Xu's first hire was Rotor CTO Yiou He SM '14, PhD '20, whom Xu worked with during his PhD. The decision was a sign of things to come: The number of MIT affiliates at the 50-person company is now in the double digits.
“The core technical team from the beginning was a group of PhDs from MIT, and they are some of the best engineers I've ever worked with,” Xu says. “They're really smart, and during grad school they built some really cool things at MIT. “That is probably the most critical factor to our success.”
To help get Rotor off the ground, Xu worked with the MIT Venture Mentoring Service (VMS), MIT's Industrial Liaison Program (ILP), and the National Science Foundation's New England Innovation Corps (I-Corps) program on campus.
One of the key early decisions was to work with a known Robinson Helicopter Company aircraft rather than building an aircraft from scratch. Robinson already requires its helicopters to be serviced after about 2,000 flight hours, and that's when Rotor steps in.
The core of Rotor's solution is what is known as a “fly-by-wire” system: a set of computers and motors that interface with the helicopter's flight control functions. Rotor also equips the helicopters with a suite of advanced sensors and communication tools, many of which were adapted from the autonomous vehicle industry.
“We believe in a long-term future where there will no longer be pilots in the cockpit, so we are building for this remote pilot paradigm,” Xu says. “It means we have to build robust autonomous systems on board, but it also means we need to build communication systems between the plane and the ground.”
Rotor can leverage Robinson's existing supply chain and potential customers feel comfortable with an airplane they've worked with before, even if there's no one sitting in the pilot's seat. Once Rotor's helicopters are in the air, the startup offers 24/7 flight monitoring with a cloud-based human oversight system the company calls Cloudpilot. The company is starting flights in remote areas to avoid risks of human injury.
“We have a very careful approach to automation, but we also have a highly trained human expert,” Xu says. “We get the best of autonomous systems, which are very reliable, and the best of humans, who are really excellent at making decisions and dealing with unexpected scenarios.”
Autonomous helicopters take off
Using small planes to do things like fight fires and deliver cargo to offshore sites is not only dangerous, it's also inefficient. There are restrictions on the amount of time pilots can fly and they cannot fly during adverse weather conditions or at night.
Most current autonomous options are limited by small batteries and limited payload capabilities. Rotor's plane, called the R550X, can carry loads of up to 1,212 pounds, travel at more than 120 miles per hour and be equipped with auxiliary fuel tanks to stay in the air for hours at a time.
Some potential customers are interested in using the aircraft to extend flight times and increase safety, but others want to use the machines for entirely new types of applications.
“It's a new plane that can do things that other planes couldn't do, or maybe even if they technically could, they wouldn't do with a pilot,” Xu says. “You could also think of new scientific missions enabled by this. I hope to let people's imagination discover what they can do with this new tool.”
Rotor plans to sell a small handful of planes this year and scale production to produce 50 to 100 planes a year thereafter.
Meanwhile, in the much longer term, Xu hopes Rotor will play a role in getting it back into helicopters and, eventually, transporting humans.
“Today, our impact is very much about safety, and we are solving some of the challenges that have stumped helicopter operators for decades,” Xu says. “But I think our biggest future impact will be to change our daily lives. “I am excited to fly safer, more autonomous and more affordable vertical take-off and landing aircraft, and I hope Rotor will be an important part of enabling this.”
