Avidyne Envelope-Protecting Autopilot ApprovedBy Mac McClellan
March 3, 2011 —Avidyne’s new DFC100 autopilot, along with other elements of its Entegra Release 9.2 avionics system, has been approved by the FAA for installation in the Cirrus SR20 and SR22 series airplanes.
The biggest advance in the new system: the DFC100 autopilot that prevents the airplane from stalling or exceeding maximum airspeeds when the autopilot is engaged will now issue audible and visual warnings if the airplane is nearing normal attitude and speed limits even when the autopilot is not engaged.
Accident records show that loss of control is the biggest single cause of accidents for general aviation airplanes flying in the clouds. The DFC100 helps prevent loss of control by warning the pilot if he has selected a command that brings the airplane close to a stall. If the pilot doesn’t respond with more power or a mode change, the autopilot will continue to issue the warnings visually and audibly while gently lowering the nose to gradually trade altitude for enough airspeed to avoid the stall.
Of course, when it is engaged, the autopilot will not fly the airplane into an unusually steep bank, nor will it lower the nose enough to exceed the airspeed limitation. But when the DFC100 is not engaged and the pilot is hand flying, the system will issue warnings if those parameters are exceeded, or if the pilot is flying too slowly and approaches a stall.
If a pilot hand flying with the DFC100 system becomes disoriented and receives the alerts, he can press the “straight and level” button and the autopilot will roll the airplane level and maintain a safe airspeed while the pilot regains situational awareness.
Release 9.0 is a comprehensive integrated avionics system that includes flat glass displays and a full capability flight management system (FMS) along with communications radios. It is offered as a retrofit in existing Cirrus airplanes no matter what avionics were originally installed. Other very important features of the system are dual AHRS so that the flight control system and displays continue to function after the failure of one of those critical non-moving electronic gyros. The system has all of the operating modes expected in avionics designed for jets and turboprops, including vertical navigation modes and the unique FMSVectors mode that shows the track of the airplane over the ground when heading mode is selected.
For airplanes already converted to Entegra Release 9.0 avionics system adding the new DFC100 autopilot costs $14,990. The complete Entegra Release 9.0 system price begins at $59,000. For more information see Avidyne’s website.