Accident Details
On August 7, 2012, about 1016 central daylight time, a Cessna 177B, registration N34283, was substantially damaged during recovery after a loss of control while en route to Evansville Regional Airport (EVV), Evansville, Indiana. The pilot and passenger were not injured. The airplane was operated under 14 CFR Part 91 as a personal flight. Instrument meteorological conditions prevailed, and the flight was on an IFR flight plan. It had departed from Stuart Powell Field Airport (DVK), Danville, Kentucky, about 0956, with EVV as the intended destination.
Flight History
The pilot reported a loss of attitude reference and subsequent loss of control while in instrument meteorological conditions (IMC). About 15 minutes into the flight, the attitude indicator showed a 30-degree right bank, and control inputs did not correct the bank. The pilot then noted a 2,000-foot-per-minute descent with increasing airspeed. The attitude indicator and turn coordinator displayed conflicting information; the directional gyro indicated a rapid heading change to the left. At about 5,000 feet mean sea level (msl), the airplane broke out of clouds, and the pilot regained control. Airspeed exceeded limitations during the event. The pilot reported no apparent structural damage and elected to continue in visual meteorological conditions (VMC). Flight instruments operated normally until final approach, when the attitude indicator again displayed a 30-degree right bank, persisting through landing and taxi. After landing, the pilot observed substantial wing damage.
Radar track data showed the airplane cruising at about 8,000 feet msl near Bardstown, Kentucky, at the time of loss of control. At about 1016, the airplane reversed course briefly, entered a right turn, and then returned to a westerly course toward the destination. It descended to about 5,000 feet msl during the event.
Postaccident Examination
Examination of the airplane revealed damage to both wings. Upper wing skins were wrinkled from about 3 feet outboard of the wing root, extending outboard and aft, affecting three wing stringers. The left and right forward fuel tank bulkheads were damaged. The airframe vacuum system tested normally. The attitude indicator exhibited significant noise during testing, consistent with an impending gyro bearing failure, and did not fully stabilize after being disturbed from equilibrium. The vacuum pump showed no anomalies.
The pilot noted that a backup attitude indicator might have prevented the loss of control and subsequent accident; however, regulations did not require a secondary attitude indicator for the flight.