# NTSB CEN12LA532: Cessna 177B, N34283, Evansville, IN, August 7, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 7, 2012, 10:16 local (15:16 UTC) - Place: Evansville, IN - Coordinates: 38.038612, -87.53083 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.0386&lon=-87.5308&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report January 22, 2013 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA -- Indianapolis Flight Standards - NTSB case key (mKey): 84616 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12LA532 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84616/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84616 - Page: https://openairdocs.org/ntsb/CEN12LA532 ## 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. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Indicating/recording systems: instrument panel ](https://openairdocs.org/ntsb-findings/01023110): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Cessna 177B, 2 cases](https://openairdocs.org/ntsb-findings/01023110/cases.md?model=2073708), [All aircraft, 22 cases](https://openairdocs.org/ntsb-findings/01023110/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Flight instrument malf/fail](https://openairdocs.org/ntsb-events/334); cases with it: [Cessna 177B, 1 case](https://openairdocs.org/ntsb-events/334/sequence.md?model=2073708), [All aircraft, 56 cases](https://openairdocs.org/ntsb-events/334/sequence.md) - [Enroute-cruise: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Cessna 177B, 8 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=2073708), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) ## Analysis 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. ## Factual narrative On August 7, 2012, about 1016 central daylight time, a Cessna 177B, 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 registered to and operated by private individuals under the provisions of 14 Code of Federal Regulations Part 91 as personal flight. Instrument meteorological conditions prevailed for the flight, which was operated on an instrument flight rules flight plan. The flight originated from Stuart Powell Field Airport (DVK), Danville, Kentucky, about 0956. The intended destination was EVV. The pilot reported a loss of attitude reference and a subsequent loss of control during cruise flight in instrument meteorological conditions (IMC). About 15 minutes into the flight, the attitude indicator displayed a 30-degree right bank and his control inputs did not appear to be correcting 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 (msl), the airplane broke out of the clouds and the pilot was able to regain control. The airspeed indications did exceed the airplane limitations during the event. The pilot reported that there did not appear to be structural damage and he elected to continue the flight in visual meteorological conditions (VMC). The indications of the flight instruments were normal until the flight was on final approach. At that time, the attitude indicator again displayed a 30-degree right bank, which continued for the remainder of the approach, landing, and taxi. The pilot reported observing substantial damage to the wings after landing. Radar track data indicated that the airplane was established in cruise flight about 8,000 feet mean sea level (msl) in the vicinity of Bardstown, Kentucky, at the time of the loss of control. About 1016, the airplane reversed course briefly, before it entered a right turn and subsequently returned to a westerly course toward the intended destination. The airplane descended to about 5,000 feet msl during the event. A postaccident examination of the airplane revealed damage to both wings. The upper wing skins were wrinkled beginning about 3 feet from the wing root and extending outboard and aft. The damage extended to and included 3 wing stringers. The left and right forward fuel tank bulkheads were also damaged. Testing of the airframe vacuum system did not reveal any anomalies. The attitude indicator was removed from the airplane. It exhibited 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. Examination of the vacuumpump did not reveal any anomalies. The pilot noted that the presence of a backup attitude indicator might have prevented the loss of control event and the subsequent accident. However, regulations did not require a secondary attitude indicator or indicating system for the accident flight. ## Aircraft - Registration: [N34283](https://openairdocs.org/aircraft/N34283), registered now, S/N 17701748, built 1972 (OpenAirDocs) - Reported make and model: CESSNA 177B - Registry model: [Cessna 177B](https://openairdocs.org/model/cessna-177b) (registry code 2073708) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17701748 - Airframe hours: 2671 - Engines: LYCOMING O-360-A1F6 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 22, 2011, 18 hours before - Departed: DVK, Danville, KY - Destination: Evansville, IN - Flight plan: IFR - Airport: EVV, Evansville Regional ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; injuries: none; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review April 20, 2012; seat: right; flight hours: 2,295 total, 7 in this make and model, 2,060 as pilot in command, 168 in the last 90 days, 71 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 2 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 73 °F - Altimeter: 30.02 inHg - Observed at: FTK, 17 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20120807017269A](https://openairdocs.org/incident/20120807017269A), Aug 7, 2012: Cessna 177B, Bardstown, KY, Substantial damage. During cruise flight in instrument meteorological conditions at approximately 7,500 MSL, the attitude indicator began to give erroneous indications that the… ## Docket (3 files) The files NTSB released with the investigation on November 21, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84616. 1.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 862 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40378987&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Radar Track Data Listing (item 2, .PDF, 119 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40379078&FileExtension=.PDF&FileName=Radar%20Track%20Data%20Listing-Master.PDF - FAA Inspector Statement (item 3, .PDF, 167 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40379082&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Redacted.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.