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.
