Pilot Debrief

CESSNA 177B near Evansville, IN — 2012-08-07

Final reportCEN12LA532
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Date
2012-08-07
Location
Evansville, IN, USA
Airport
EVV
Aircraft
CESSNA 177B
Registration
N34283
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Cruise

Probable cause

The pilot’s loss of control due to an inaccurate attitude reference, which was caused by an impending (“in process”) failure of the bearing in the attitude indicator.

NTSB narrative

The pilot reported a loss of attitude reference and a subsequent loss of control during cruise flight in instrument meteorological conditions. About 15 minutes into the flight, the attitude indicator displayed a 30-degree right bank and the pilot’s control inputs did not seem to correct the banked condition. The pilot subsequently noticed a 2,000 foot-per-minute descent with increasing airspeed. The attitude indicator and turn coordinator were displaying conflicting information, and the directional gyro was indicating a rapid heading change to the left. About 5,000 feet mean sea level, the airplane broke out of the clouds, and the pilot was able to regain control and landed without further incident. The pilot observed substantial damage to the wings after landing. A postaccident examination of the attitude indicator revealed significant noise during testing, consistent with an impending gyro bearing failure. In addition, after the gyro was allowed to reach operating speed, it did not fully stabilize again after it was disturbed from equilibrium. Postaccident examination of the vacuum pump and airframe vacuum system did not reveal any anomalies.

Analysis

Primary failure mode
Loss of control
First missed decision gate
Pilot could have opted to divert or return before loss of control escalated.

NTSB coding

Evidence available

  • ADS-B / radar
  • 3 docket documents
View NTSB final reportView NTSB docket

Docket documents3

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