Flight Control Reimagined

HAI/Andy Stenz

Skyryse technology aims to eliminate general aviation fatalities.

Trapped in the back seat during repeated five-hour car trips across the American Midwest to visit family as a child, Mark Groden began to imagine better, safer ways to make the journey. Airlines weren’t an option, since the 40-minute flight entailed a two-hour–plus drive each way. Private aircraft also were out: Groden’s parents weren’t pilots, and they lacked the means to stay current in an aircraft even if they had been.

Now, seven years after earning a doctorate in engineering from the University of Michigan, Groden is nearing fulfillment of his childhood dream. Skyryse (pronounced “SKY-rise”), the El Segundo, California–based company he founded in 2016, is working toward earning an FAA supplemental type certificate (STC) to install an automated flight control system on the Robinson R66. The company, which has partnered with Robinson on the project since 2020, says it aims to have an STC-equipped R66 flying in commercial service daily by about September 2024. On Jun. 28, 2023, Skyryse announced that the company was moving its daily FlightOS testing to the R66, which now includes production versions of FlightOS and a full production-representative sensor suite.

“A lot of people have realized that we have a transportation problem,” Groden, Skyryse’s CEO, told ROTOR at HAI HELI-EXPO 2023 this past March. “Many are trying to develop new aircraft types, electric vertical takeoff and landing [eVTOL] ones, and what have you. But to me, the problem always felt like it was more, How do you make existing pilots and existing aircraft more capable, safer, and have higher utility?”

Fly by Wire for Any Aircraft

To reach that goal, Skyryse has developed a suite of technologies (or “technology stack”) to replace a currently certificated aircraft’s flight control system with a fly-by-wire, IFR-certificated operating system called FlightOS. Skyryse aims to have FlightOS certificated to 14 CFR Part 25 commercial airliner airworthiness standards, with a projected failure rate of 10–9, or 1 failure in 1 billion operations. (That’s three orders of magnitude greater than the standard required of most certificated helicopters and general aviation airplanes.) The helicopter STC would also comply with Part 27 for normal category rotorcraft.

FlightOS is intended to be aircraft agnostic, capable of being retrofitted or installed on a production line on any aircraft, Groden says. While the R66 STC is Skyryse’s lead project, he says, the company has agreements to pursue such certifications with four other major aircraft manufacturers, which he declines to name. Robinsons are considered among the most challenging aircraft for an STC application from the standpoints of volume, weight, power, and flight-control responsiveness requirements.

The Skyryse design replaces the R66’s cyclic, collective, and anti-torque pedals with triply redundant, dissimilar systems linked to actuators on the swashplate. The system incorporates redundant power supplies and is operated by the pilot through two touchscreen flight controls, which the company describes as “simple and intuitive,” and a joystick. The current screens are iPads.

Skyryse developed FlightOS to support safe, automated aircraft operations, and Groden says the system provides the functionality of a conventional, all-axis autopilot while controlling and managing every system in the aircraft. FlightOS includes flight envelope protection control, advanced navigation, and data analysis capabilities designed to assess and adjust to terrain, wind conditions, and other variables.

In designing the system, Groden says, the Skyryse team took a “first principles” approach, identifying the most fundamental elements a pilot would need to achieve situational awareness and safely fly an aircraft. “If you looked at a conventional cockpit for the first time, you’d say, ‘This doesn’t look like it’s designed around a human at all,’ ” he says.

“The real innovation [with FlightOS] is that we started with the human and worked backwards, getting our system to feel intuitive and natural,” Groden said during a late 2022 visit to Skyryse by HAI President and CEO James Viola and US National Transportation Safety  Board (NTSB) Vice Chairman Bruce Landsberg.

Both Viola and Landsberg had the opportunity to fly a FlightOS-equipped R44. While Viola has logged thousands of rotorcraft hours, Landsberg’s experience is in fixed-wing aircraft. However, after a 15-minute training session on FlightOS, both pilots were able to take off, hover, fly, and land the Skyryse-equipped helicopter.

Reducing the Pilot’s Burden

Besides interpreting sensory inputs from conventional cockpits, Groden says, pilots “have to memorize the entire pilot operating handbook [POH]” to deal with normal and emergency conditions. When you’re flying a helicopter, with one hand on the cyclic and the other on the collective, “you don’t have an extra limb to grab the POH and read it, so therefore you have to know everything by heart and know exactly what to do. An airplane isn’t much better,” with the proliferation of onboard systems.

Of the pilot dictum “aviate, navigate, communicate,” in that order, Groden says FlightOS is designed to let the pilot focus on the latter two steps.

“The pilot is still in control of the aircraft but shouldn’t have to, in today’s world, worry about keeping the helicopter in the sky,” he says. “Because we’re [aiming to be certificated to a failure rate of] 10–9, the system only has one mode of operation. It never lets go. It’s always in control and right there with you. That reduces the pilot’s burden of having to successfully aviate the platform.

“Our technology stack is much more than just a conventional fly-by-wire system or an avionics suite,” Groden adds. “The category a lot of folks put us in is ‘simplified vehicle operations.’ ”

Higher-Level Decision-Making

FlightOS is targeted to help eradicate the biggest killers in the helicopter industry and, more widely, general aviation: controlled flight into terrain (CFIT), unintended flight into instrument meteorological conditions (UIMC), and aircraft loss of control. “These are things that we nearly make an impossibility with our technology stack,” Groden says.

After his experience flying the Skyryse helicopter, Viola was impressed, commenting that the fly-by-wire aircraft flew just like his own R44. He also saw FlightOS’s potential to improve safety in general aviation.

“It’s got a lot of capability,” Viola says. “The NTSB recommends you fly IFR if you’re carrying passengers. The ability this system brings to do that all the time is there, and it’s there today.”

Viola notes that the root of many of the vertical aviation industry’s safety challenges lies in inadequate aeronautical decision-making (ADM). New, advanced capabilities in aircraft don’t change the need for good decision-making in the air, but they may free pilots to focus on doing that.

Asked about the Skyryse system’s impact on ADM, Groden says, “Right now, people are required to make the decisions at very high levels and very low levels. You’re making a decision in real time, almost all the time, about keeping yourself safely inside the flight envelope. What we try to do is take the aviate part off the table so you can focus on the higher-level decision-making, where we think [the pilot is] best leveraged to maximize the safety of the flight. You still have full authority. You still have full control over the aircraft, but you’re not actively stick-and-rudder working to control the aircraft to keep it on a trajectory and keep it safely in the sky.”

FlightOS is based not only on Skyryse’s operational and flight test experience, but also on that of other companies. In its seven years, Skyryse’s team has included transportation experts from Airbus, Boeing, Ford, General Atomics, JetBlue, Moog, SpaceX, Tesla, Uber, the US military, and the Amazon autonomous-vehicle subsidiary Zoox.

Proof of Concept

Since its inception, Skyryse has been busy developing and testing the technology that it hopes will eliminate general aviation fatalities.

On Mar. 29, 2017, the company flew one of the first 55-lb.–plus uncrewed VTOL aircraft. The next year, Skyryse employed a Robinson R44 (fitted with enhanced vision using radar and a 360-degree camera system) in partnership with the City of Tracy, California, for that government’s air ambulance service. In 2019, Skyryse operated a high-volume, full-service, multimodal, door-to-door Part 135 air taxi service in the Los Angeles area.

Groden says undertaking traditional helicopter operations was a key element of Skyryse’s strategy. “We’ve taken the time and gone through the process of really understanding what the end users need in order to be successful,” he says.

In 2020, the company signed with Robinson to demonstrate FlightOS on its aircraft. Robinson Helicopter President Kurt Robinson confirmed that his company has been assisting Skyryse in developing an R66 automated flight control system. “We have been following their progress,” he says.

Also in 2020, Skyryse closed on $205 million in series B funding, bringing the company’s total capital raised to more than $260 million from investors that include ArrowMark Partners, Cantos, Eclipse Ventures, Fidelity Investments, Ford Motor Co. Chairman Bill Ford, Monashee Investment Management, Stanford University, and Venrock.

In April of last year, Air Methods invested $5 million in Skyryse and committed to retrofit with FlightOS more than 400 single-engine helicopters and fixed-wing aircraft in its air ambulance fleet. Calling FlightOS “a transformational technology for the industry,” Air Methods Senior VP of Aviation Operations Leo Morrissette says deploying it on the company’s aircraft “will first and foremost improve safety, lower cockpit workload, and allow our fleet to fully maximize the potential of patient care in a wide range of aircraft models and types.”

The air ambulance operator plans to install FlightOS on its fleets of Airbus EC130 and AS350 helicopters as well as its Bell 407s and Pilatus single-engine turboprop PC-12s, removing all current avionics suites in the process.

“In seven years of flight testing that’s been nearly every single day, we’ve also been testing different ways to control the aircraft and engage the pilot to control the aircraft,” Groden says. “I think what sets us apart, in addition to a very pragmatic approach that’s well informed by our real-world experiences, is that we’ve actually been testing different pieces of this technology for a very long time and learning on a daily basis with that feedback loop.”

Skyryse has grown from around 30 employees at the start of 2022 to nearly 100 by March 2023, and it’s recruiting engineers. In March, it opened its new headquarters in El Segundo.

This year is shaping up to be exceptional for Skyryse. The plan is to maintain throughout the year the momentum with which the company started 2023 and carry that into Anaheim, California, at HAI HELI-EXPO 2024 next year. Skyryse plans to unveil a prototype that’s more representative of its STC system, including aviation-grade touchscreens in place of the current iPads, at Los Angeles–area events in mid-November.

Achieving its goal of having a FlightOS-equipped R66 in daily commercial service by September 2024, of course, depends on Skyryse’s progress with FAA STC certification. The company said in February that a major system review with the FAA resulted in 100% approval of its proposed means of compliance for full installation.

Progress may hinge on decisions the Skyryse team made at the very start of FlightOS’s development, Groden says.

“The approach we took at the outset was to follow existing certification pathways and bases the FAA has created over the last 30 or 40 years in developing Part 25 fly-by-wire automation systems and flight-control stacks,” he says. “We decided we weren’t going to invest in or build into our product anything that doesn’t have a certification basis.”

After that, it was a matter of explaining that rationale to the FAA.

Groden adds that his company’s approach helped gain the agency’s buy-in.

“The FAA’s mandate is to keep people safe, in the sky and beneath it,” Groden adds. “That’s what we’re about as a company.”