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37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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An ATR72 in descent at 12000 ft had the #1 engine propeller go to the feather position uncommanded caused by an intermittent electrical connector on the propeller control unit.
| Attributes | |
| ACN | 427430 |
| Time | |
| Date | 199901 |
| Day | Wed |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : hrl |
| State Reference | TX |
| Altitude | msl bound lower : 12000 msl bound upper : 12000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tower : ord |
| Operator | common carrier : air carrier |
| Make Model Name | ATR 72 |
| Navigation In Use | Other |
| Flight Phase | descent other other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Experience | flight time last 90 days : 60 flight time total : 8000 flight time type : 1200 |
| ASRS Report | 427430 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial |
| Events | |
| Anomaly | aircraft equipment problem : critical other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | flight crew : declared emergency other |
| Consequence | Other |
Narrative:
The #1 engine feathered with an eec fault. We performed checklist for fault and troubleshot engine propeller feathering. After shutdown and restart, engine propeller unfeathered after 5 mins of stabilization. Reason propeller feathered is unknown. Callback conversation with reporter revealed the following information: the reporter stated the aircraft was an ATR72 with P&west PW127 engines and had several reports on this aircraft and engine of uncommanded feathering in-flight. The reporter said the engine manufacturer was advised of the problem and gave us help to correct the malfunction. The reporter stated the trouble was an intermittent electrical connector on the propeller control unit which intermittently had 2 pins short together and operate the feather pump driving the propeller to feather.
Original NASA ASRS Text
Title: AN ATR72 IN DSCNT AT 12000 FT HAD THE #1 ENG PROP GO TO THE FEATHER POS UNCOMMANDED CAUSED BY AN INTERMITTENT ELECTRICAL CONNECTOR ON THE PROP CTL UNIT.
Narrative: THE #1 ENG FEATHERED WITH AN EEC FAULT. WE PERFORMED CHKLIST FOR FAULT AND TROUBLESHOT ENG PROP FEATHERING. AFTER SHUTDOWN AND RESTART, ENG PROP UNFEATHERED AFTER 5 MINS OF STABILIZATION. REASON PROP FEATHERED IS UNKNOWN. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS AN ATR72 WITH P&W PW127 ENGS AND HAD SEVERAL RPTS ON THIS ACFT AND ENG OF UNCOMMANDED FEATHERING INFLT. THE RPTR SAID THE ENG MANUFACTURER WAS ADVISED OF THE PROB AND GAVE US HELP TO CORRECT THE MALFUNCTION. THE RPTR STATED THE TROUBLE WAS AN INTERMITTENT ELECTRICAL CONNECTOR ON THE PROP CTL UNIT WHICH INTERMITTENTLY HAD 2 PINS SHORT TOGETHER AND OPERATE THE FEATHER PUMP DRIVING THE PROP TO FEATHER.
Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.