Simulators Still Not Accurate Enough On Stalls

As experts struggle to identify why the crew of Air France 447 lost control of their A330 over the South Atlantic Ocean nearly four years ago, the industry is also still struggling to develop the precision data needed to accurately reproduce a stall in a Level D simulator. The lack of accurate stall data limits entry and recovery practice because the computers running the simulators have no idea how the aircraft will actually perform.

Safety experts believe better data is needed to properly prepare pilots for a portion of the aircraft’s performance envelope that was once thought easy to avoid.

At a recent conference held at the Royal Aeronautical Society in London, officials from both Airbus and Boeing joined forces to explain the situation to date as well as where the industry still needs to go. Airbus test pilot Terry Lutz believes the day may be coming when pilots will need to hand over more control to onboard computers when the situation becomes too chaotic. This is reminiscent of the blue “level” button in use aboard the four-place Cirrus SR22 piston single that automatically brings the aircraft back to a wings-level attitude even if the autopilot is turned off.

Boeing engineer Paul Bolds-Moorhead reiterated the monumental task of developing accurate lift and stall data in the high-altitude regime, where the stall and unusual-attitude behavior of transport aircraft is typically never tested.