Prohibits Autopilot-Induced Stall And Overspeed Situations

Avidyne announced Thursday that their new DFC90 and DFC100 autopilot systems will include Avidyne Autopilot Flight Envelope Protection, a safety-enhancing feature that prohibits inadvertent autopilot–induced stall and overspeed situations. The DFC90 and DFC100 also include a “Straight & Level” button which overrides all autopilot modes and levels the aircraft in both pitch and roll for an added measure of safety in the event of an unusual attitude or other emergency situation.

“After thorough examination of the NTSB safety data for Cirrus aircraft, we found that autopilot-induced flight envelope exceedances, particularly stall/spin incidents in altitude hold or vertical speed climb modes, are a common error and contributing cause in more than 28% of all Cirrus accidents over the past eight years,” said Steve Jacobson, Avidyne’s Vice President of Product Management.

“Envelope protection provides pilots with an added measure of safety, which can be especially vital in high work-load IFR environments where pilots might be easily distracted.”

“Avidyne has always been focused on developing products that make flying easier and safer, and autopilot-induced stall  prevention takes general aviation flight control systems to a whole new level,” said Dan Schwinn, Avidyne’s President and CEO. “As part of our over-arching initiative to dramatically enhance general aviation safety, we were keenly interested in developing a flight control system that not only provides exceptional flying characteristics during normal operation, but also provides an unobtrusive yet authoritative method of reducing inadvertent stalls and over-speed situations, and the DFC90 and DFC100 systems do that very well.”

DFC90

For envelope protection, available lift and speed margin are calculated constantly in the background whenever any mode, including Flight Director modes, are in operation. As the aircraft approaches stall, the autopilot gradually reduces maximum  bank and vertical speed just enough to keep the wing flying, while visually and audibly annunciating the condition to the pilot. As a result, departure from controlled flight is prevented with the least impact on achieving mission-level objectives like navigation, climb or approach.

Overspeed is handled similarly, with anticipation and minimal but effective inputs. In Flight Director modes, all these actions appear as guidance cues with corrections blended into the "V-bar" commands.

Flight Envelope & Overspeed Protection are a standard features of the DFC90 and DFC100 autopilots. The DFC90 & DFC100 systems are scheduled for certification and delivery in mid-2010.

The retail price of the DFC90 for Entegra-equipped Cirrus aircraft is $9,995 and requires Entegra PFD Software Release 8.0. The retail price of the DFC100 for Entegra Release 9-equipped Cirrus aircraft is $14,995.

FMI: www.avidyne.com