The company has flown more than 50 tests following a world-first automated autorotation emergency procedure on Jul. 22, 2023.
Aviation software and safety technology start-up Skyryse has performed more than 50 autorotation tests of its simplified, automated flight control system for the Robinson R66, including a full-down autorotation in July.
According to El Segundo, California–based Skyryse, the Jul. 22 full-down test at its Los Angeles–area flight test facility represented a major breakthrough, marking the completion of the first-ever fully automated autorotation emergency procedure, a feat certified by Guinness World Records. “Fully automated autorotation is just one example of how our technology will bring a commercial grade of safety and beyond to general aviation,” says Mark Groden, the company’s founder and CEO.
Founded in 2016, Skyryse aims to produce an intuitive, aircraft-agnostic system that enables fly-by-wire, IFR-certificated capabilities at the reliability of 10-9 (or one failure in 1 billion operations) prescribed by 14 CFR Part 25 commercial airliner airworthiness standards. That’s three orders of magnitude greater than the standard required of most certificated helicopters and general aviation aircraft. The company launched its automated flight control system (formerly called FlightOS) with Robinson Helicopter Co. in 2020 at the same time it began pursuit of an FAA supplemental type certificate (STC) to install the system on the R66.
Skyryse has performed “significantly more than 50” autorotation tests of the R66 system, says Ray Wert, head of communications. The company has flown engineering simulator and airborne tests in a variety of conditions, including straight-in and 180-degree autorotation procedures. The flight tests seek to demonstrate the system’s ability to satisfy requirements of 14 CFR 27.71 (autorotation performance), 27.75 (landing), 27.175 (demonstration of static longitudinal stability), and other FAA regulations.
“Upon entry into service,” Groden says, “we will have completed testing throughout the applicable envelope for the R66.”
Skyryse plans to unveil the first production R66 featuring its system in the first quarter of 2024. The company has set a goal of an STC–equipped R66—compliant with 14 CFR Part 27 (normal category rotorcraft)—flying in commercial service daily by September 2024. (Skyryse previously planned to unveil a more production-representative prototype of the R66 STC system at the CoMotion urban air mobility show in Los Angeles during November 2023 but decided against it. Wert says the decision was related to a marketing decision and not because of any technology or design issues.)
The Skyryse system is designed to automatically handle the rapid-response and continual trimming challenges that a pilot faces in executing an autorotation after a loss of power to the main rotor. Using proprietary redundant flight controls and a suite of sensors, the system can quickly recognize a power failure and execute the multiple steps required to carry out a successful autorotation.
The Skyryse design replaces the R66’s cyclic, collective, and antitorque pedals with triple-redundant, dissimilar systems linked to actuators on the swashplate. The system incorporates redundant power supplies. The pilot operates the system through two touchscreen flight controls, which the company describes as “simple and intuitive,” and a joystick. Originally using Apple iPads for flight controls, Skyryse plans an upgrade to aviation-grade touchscreens.
Skyryse test pilot Jason Trask explains that an R66 pilot has two seconds after power loss to enter autorotation, which involves lowering the collective (allowing the main rotor to be driven by the upflow of air during the descent), then pulling the cyclic to slow the aircraft and stepping on the right antitorque pedal to keep the nose straight. “If you don’t reduce the collective [and lower the main-rotor blade pitch], within a few seconds the drag of the blades will cause the rotor to stop moving,” Trask says. “At that moment, there is no more lift in the helicopter.”
In addition, the Skyryse system is designed to manage rotor rpm, airspeed, and trim during the autorotation glide and the flare before touchdown, according to Trask.
However, the system does not do everything. The pilot must select the landing point for the autorotation. Skyryse didn’t elaborate on how the pilot interacts with the system to select the landing point.
“This is actually the secret sauce of our system,” Groden says. “It handles the complexities of the autorotation maneuver and leaves the pilot with agency to select the final location of the set down.”
In addition to the effort to obtain the R66 STC, officials with Skyryse says it has agreements in place to pursue certifications with four other major aircraft manufacturers for installation of its highly automated flight control system. The company has not yet named the other OEMs.
In 2022, Skyryse signed an agreement with Air Methods to retrofit its system in more than 400 of the air medical operator’s single-engine helicopters and fixed-wing aircraft. Those aircraft include the Airbus EC130 and AS350 helicopters (or H130 and H125, respectively) as well as Air Methods’ Bell 407 and Pilatus single-engine turboprop PC-12 fleet. The retrofits will remove all current avionics suites in the process.
According to Skyryse, work is underway on securing STCs for the Air Methods H130s and H125s. In October, the company noted that Air Methods had delivered the first H130 for testing and modification.