No Checklist For This

I was flying a 2002-model A36 Bonanza (yeah, with me its always a Bonanza) home to Wichita from Thanksgiving in Ohio with my wife and our son aboard. Somewhere over Indiana, the Bonanzas attitude indicator (AI) began to tumble. The failure announced itself slowly, but very soon the instrument was pitching up and down in very distracting oscillations. It then displayed a range of indications-from off-scale nose-up pitch excursions to slightly below 20 degrees nose-down-in a roughly two-second cycle, while indicating bank angles between wings-level and about 10 degrees left.

Tom Turner

Wednesday, January 02, 2019 at 12:00 AM ET

Verified

Key Takeaways:

An attitude indicator failure requires immediate action to maintain aircraft control, identify/confirm the failure, and cover the distracting instrument.
Pilots must be prepared for instrument failure by knowing their aircraft systems, autopilot behavior (especially if rate-based), and having a pre-developed plan for troubleshooting and backup procedures.
Regular practice of partial-panel flying and maintaining proficiency are crucial for safely managing instrument failures, particularly in instrument meteorological conditions (IMC).
In the event of an AI failure, prioritize maintaining control, utilizing any functioning autopilot (especially if rate-based), aiming for visual meteorological conditions (VMC), and declaring an emergency if in IMC.

See a mistake? Contact us.

I was flying a 2002-model A36 Bonanza (yeah, with me it’s always a Bonanza) home to Wichita from Thanksgiving in Ohio with my wife and our son aboard. Somewhere over Indiana, the Bonanza’s attitude indicator (AI) began to tumble. The failure announced itself slowly, but very soon the instrument was pitching up and down in very distracting oscillations. It then displayed a range of indications—from off-scale nose-up pitch excursions to slightly below 20 degrees nose-down—in a roughly two-second cycle, while indicating bank angles between wings-level and about 10 degrees left.

Although indications began slowly, I immediately knew something was wrong because the airplane’s KFC225 autopilot—which references the AI—disconnected as soon as the instrument’s gyroscope lost stabilization. Although the flight director command bars remained elevated (making it look like the autopilot might still be operating), the autopilot disconnected. The autopilot’s annunciator flashed a few times, then extinguished and the autopilot disconnect horn chirped.