Sikorsky’s recent flight test of its Optionally Piloted Vehicle (OPV) aboard an S-70 marked the first demonstration of a retrofit fly-by-wire (FBW) kit that is designed to enable autonomy in legacy fixed- and rotary-wing aircraft. The OPV Black Hawk flew on May 29 under the U.S. Defense Advanced Research Projects Agency Aircrew Labor In-Cockpit Automation System (ALIAS) program.
Collins Aerospace (Chalet 344) worked with Sikorsky on a kit that replaced the mechanical linkage path with an enhanced flight control computer, cockpit interface unit, and electromechanical actuators/actuator control units.
The FBW kit was the culmination of nearly four years of collaboration between the companies that began with the flight test of components of the FBW system aboard an S-76 aircraft as part of the Sikorsky Autonomy Research Aircraft (SARA demonstrations), said Darryl Woods, general manager of control systems for Collins Aerospace. That aircraft still had mechanical systems, but the test spurred interested in a full FBW kit, Woods added.
The FBW kit was designed as a triple redundant system that is a “jam free” system with magnetic coupling that eliminates a need for gearing, ball screws, or clutches. Logic typically residing within the primary flight control computer resides externally in its own control module or the actuator itself, simplifying the architecture and increasing reliability, Collins said.
The system was also designed for ease of installation to reduce downtime, added Steve Avritch, chief flight control engineer for Collins Aerospace. This is possible because the retrofit doesn’t involve modifications to the hydraulic system or hydraulic actuator, negating any need to requalify the hydraulic system.
The FBW kit is a prototype, using an enhanced flight control computer. But it eventually will be integrated with Collins Aerospace’s next-generation vehicle management computer (VMC) that is under development and will provide 20 times the computing power, further enabling FBW and autonomous technologies. Collins Aerospace believes the timing of the FBW kit will align with the development of the VMC, which should be ready for market near the end of 2020 or early 2021.
While under test with for the ALIAS program, the system could be a retrofit option on a range of legacy aircraft or rotorcraft, Avritch said. Collins Aerospace is in talks with possible applications. Also, the Army is working with Sikorsky to test the system aboard one of its UH-60M Black Hawks.
Collins Aerospace is designing the system for possible civil certification, Avritch added, saying it will meet such requirements in anticipation of potential applications. The system, he said, can also bring substantial benefits to legacy aircraft. “The quality of the handling is dramatically improved,” he said, adding that it can lower operational costs and remove the need for maintenance of the mechanical systems.
“By reducing pilot workload through the autonomous performance of certain flight operations, we can help improve safety, reliability, and efficiency for both military and commercial operators across a variety of platforms,” said Collins Aerospace Power & Controls president Tim White.