Cobham’s HeliSAS two-axis helicopter stability and autopilot system has received its first supplemental type certification (STC) from the FAA for use in a Robinson R44 helicopter.
HeliSAS is a two-axis attitude hold, attitude command, flight-control system. The system has two basic functions, a stability augmentation system (SAS) to aid with aircraft stability and autopilot outer loop control modes for altitude hold, heading select, and navigation sensor coupling. The SAS and autopilot system provide a significant reduction in pilot workload, from takeoff to landing.
In addition, HeliSAS’ parallel design requires fewer components, significantly reducing system weight. These factors combine to make HeliSAS particularly well suited for helicopters with hydraulic control systems. It provides helicopter pilots with precise control during all modes of flight, regardless of wind conditions or shifts in weight. The system is designed to be engaged at all times.
Autopilot functions once reserved for higher priced and more complex stabilization systems are included in HeliSAS. They include functions such as heading select and hold, altitude hold, ILS localizer and glideslope capture and tracking (including back course), VOR capture and tracking, GPS steering, and LVAV/VNAV approach capability.
Working with Hoh Aeronautics Inc. of Lomita, Calif., Cobham is in the process of achieving HeliSAS certification for use on the Bell 206, Bell 407, Eurocopter AS350, and U.S. Navy’s TH-57 helicopters. The company states advantages such as ease-of-installation and competitive pricing.