Double Or Nothing?

There can no longer be any debate: The advent of the attitude heading air-data reference system (ADHRS) and its incorporation into electronic flight information displays (EFIS has revolutionized the way pilots fly in instrument conditions. The ADHRS/EFIS combination have eliminated the brain-sopping task of repeatedly scanning in rapid succession six key analog instruments, some round power dials and annunciator lights while gleaning critical flight information. The pilot had to first process the information it received from the attitude indicator, altimeter, airspeed indicator, directional gyro/horizontal situation indicator, turn coordinator and vertical speed indicator through her vision, compare it with navigational information and develop, on her own, a three-dimensional picture of where the airplane was in space-time. By the time all that has been accomplished, the situation has changed, since the pilot and the craft are moving at a pretty good clip.

Key Takeaways:

• Modern electronic flight information displays (EFIS) in light aircraft, while revolutionizing instrument flight, critically rely on a single Attitude Heading Air-data Reference System (ADHRS).
• This single ADHRS unit constitutes a dangerous single point of failure, potentially leaving IFR pilots without crucial attitude and heading data and reverting to inadequate or poorly placed backup instruments.
• The article strongly advocates for robust redundancy, recommending the installation of a second, independently powered ADHRS or a dedicated backup attitude indicator to ensure safety and effective risk management during instrument conditions.

Key takeaways sponsored by Aviator Pro | Start Your Training ->

See a mistake? Contact us.