The Future of Advanced Air Mobility

Human in the Loop: My Ride on Xwing's Self-flying Aircraft

I’m in the cockpit of a modified Cessna 208B Grand Caravan, descending from an altitude of about 4,000 feet down to California’s Yolo County Airport, just west of Sacramento. Seated to my left, the pilot is glancing over his landing checklist but keeps his hands off the controls. The yoke turns and presses forward as we prepare for the landing, all while the pilot’s hands are resting in his lap—almost as if a ghost has taken control of the aircraft. 

But there are no ghosts at the helm of this airplane. Rather, it is being flown by Xwing’s trademarked “Superpilot,” a fully autonomous flight system that Xwing installed on this otherwise ordinary Cessna aircraft. The Superpilot is capable of taking off, landing, and taxiing without any pilot intervention. 

Xwing aims to operate a fleet of these modified Cessnas under a supplemental type certificate, which will allow it to use the unpiloted aircraft for autonomous cargo delivery flights. Rather than have a safety pilot on board, as there was during my demonstration flight, Xwing will have ground controllers supervising multiple simultaneous flights from the company's mission control center.

The company has been flight-testing its Superpilot autonomous flight system for the last two years under an experimental certificate for research and development purposes, and it achieved the first fully autonomous gate-to-gate flight in February 2021. 

Xwing's Superpilot uses a combination of software and hardware to control the aircraft while providing complete situational awareness. The aircraft is equipped with dozens of sensors, as well as cameras, radar, and LIDAR systems mounted under the aircraft’s wing. The Superpilot combines data from those sensors with real-time airspace, airport, weather, and terrain map data to create a comprehensive view of its environment. 

The San Francisco-based company says its Superpilot system can automatically detect and avoid hazards, such as other aircraft, both in the air and on the ground. However, during our demonstration, adjustments to the planned flight path were all done remotely by Xwing’s ground controllers, located in a small trailer at the airport. 

Xwing’s flight test operations manager monitors the flight from inside the mobile mission control center.
Inside Xwing's mobile mission control center at Yolo County Airport, Xwing’s flight test operations manager, Craig Milliard, monitors the autonomous flights. (Photo: Hanneke Weitering)

The role of the onboard pilot—in this case, Xwing’s safety pilot, Gabriele Di Francesco—is to supervise the autonomous flight, and to take control of the aircraft only on the off chance that there’s a problem with the Superpilot. But the Superpilot worked exactly as planned during my demonstration flight, and no pilot intervention was necessary during the autonomous landing and subsequent takeoff at Yolo County Airport. 

However, I did see Di Francesco manually fly the airplane earlier during our flight demonstration. That morning, we originally departed from Xwing’s hangar at Buchanan Field Airport in Concord, California, just northeast of San Francisco. Due to FAA rules, the experimental aircraft is not allowed to fly autonomously over densely populated areas, so the pilot had to manually control it during our first takeoff. Shortly after takeoff, as we began making our way toward Yolo County Airport, the Superpilot was turned on with the push of a button, and it was smooth sailing from there. 

Xwing’s Cessna flew fully autonomously the rest of the way to Yolo County Airport, then landed, taxied, and took off again, all without any pilot intervention. After completing a circuit above the airport, while still flying autonomously, the aircraft returned for a second landing at Yolo, after which the Superpilot taxied over to Xwing’s mobile mission control center. I hopped off the airplane and stepped inside the trailer to witness essentially the exact same flight plan, this time from the ground controller’s perspective. 

Xwing's mobile mission control center
Xwing's mobile mission control center is inside this trailer, which is at Yolo County Airport in California. The company plans to eventually build a permanent ground station for the remote operation of its entire fleet of modified Cessna airplanes. (Photo: Hanneke Weitering)

Because Yolo is a non-towered airport, meaning it has no air traffic control unit on site, Xwing’s ground controller had to monitor the local air traffic before takeoff. “Parking brake set,” a Siri-like voice said over the speaker as the taxiing Cessna came to a stop on the runway while waiting for the opportune time to begin taking off. The Superpilot identifies runway hold position markings and automatically stops to await clearance for takeoff. In this case, because Yolo airport is uncontrolled, the ground controller—Xwing’s flight test operations manager, Craig Milliard—had to give the clearance.

“Continuing taxi. Brake released,” the Superpilot’s voice announced as the aircraft continued onto the runway. “Auto takeoff initiated,” it said before the aircraft accelerated down the runway and took to the sky. 

While the Cessna flew a circuit around Yolo Airport, another general aviation aircraft was taking off from the runway below. To ensure that this aircraft did not cross paths with Xwing’s Cessna, Milliard remotely commanded the airplane to begin a “right 360” maneuver by pressing two buttons on his control panel. This briefly diverted the aircraft from its planned route by flying in a small, tangential circle to make room for the other airplane to take off. 

“So, that’s the fun of working at an uncontrolled airfield. People can fly in predictable patterns, and there’s someone taking off, so we couldn’t then circle back around across the departure path,” Milliard told FutureFlight. “Fortunately we’ve been doing this long enough that we’ve figured out how to automate various pieces of the traffic pattern. So, that was a two-button press for me to be able to build spacing behind someone and also not interfere with other traffic that’s behind us,” he explained. “Having these operations today has really been teaching us a lot about our system and how it needs to be built for future airspace integration.”

As the Cessna descended back down to the runway, the computerized voice announced, “auto-land sequence initiated.” This voice is audible both in the control room and in the safety pilot’s headset, which helps to reduce the amount of back-and-forth communication between the safety pilot and ground control crew, Milliard said. 

The Cessna once again touched down safely and taxied back to the mobile mission control center, where I boarded the aircraft one last time to begin the journey back to Buchanan Airfield. As with the first leg of our trip, the aircraft took off and cruised autonomously, but the safety pilot had to take over manual control as we flew over the more densely populated area near our destination. But as soon as we landed, the Superpilot was in control again, and the aircraft taxied itself back to Xwing’s hangar. 

While all of Xwing’s flights today have a safety pilot on board, the company is planning to eventually switch over to fully autonomous flights with no pilots in the cockpit. For now, the company is focused on certifying its modified Cessnas for fully autonomous cargo flights, but it aims to one day be able to transport passengers on pilotless airplanes as well. 

In preparation for fully autonomous cargo flights, Xwing is already operating as a Part 135 air cargo carrier and provides delivery services under a contract with UPS. Using its fleet of 35 unmodified Cessna Grand Caravans, the company makes about 400 flights per week. All of those flights, which still have onboard pilots in full control of the aircraft, are supplying Xwing with the data it needs to further refine its autonomous flight system. 

This map shows all the cargo routes that Xwing flies using its fleet of unmodified Cessna Grand Caravans.
This map shows all the cargo routes that Xwing flies using its fleet of unmodified Cessna Grand Caravans. (Credit: Xwing)

“All the data on every single flight data is being collected and then sent to a cloud,” Xwing founder and CEO Marc Piette told FutureFlight back at the hangar. “So we're caching some of that data here for quick processing and access, and then we're backing everything up to the cloud, and it's being used for all sorts of features and functionality.” 

If all goes according to plan, Xwing expects it will be able to have the autonomously piloted Caravans certified to conduct commercial cargo delivery flights without a pilot on board by 2024, with operational autonomous flights beginning in 2025. However, it's not yet clear how long it will take to certify the autonomous aircraft for pilotless commercial flights with passengers on board, as the FAA and other international regulators have yet to confirm the certification basis on which they would allow that to happen.

Piette said he believes small, unpiloted aircraft will be certified to carry passengers by the end of this decade, but certification for larger commercial airliners will take much longer. "Over time, this technology is going to keep evolving," he noted. "And of course, there's also going to be other applications supported beyond cargo. It's going to be plenty of work for the foreseeable future. Let's put it that way."