What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On 02/21/2016, at approximately 13:20 EST, a commutair DHC-8-202 aircraft flying as united express flight 4944 experienced a left engine failure and associated autofeather of the left propeller upon take-off rotation and initial climb-out. This event had been identified as a repeat of a similar incident on this same aircraft from 11 days prior. (See incident AEA0116009)
Upon investigation by the company, and detailed troubleshooting of the left engine autofeather system, it was discovered that the #1 torque signal conditioning unit(tscu) is the probable failing component for this discrepancy, and that the prior replacement of the #2 tscu on 2/10/2016 may have been inappropriate considering the system operation per aircraft maintenance manual reference 61-21-00. Based on this information, the company removed the #1 tscu and shipped the unit to pratt & whitney for teardown and evaluation. The results of this evaluation is not yet known as of 3/8/2016.
The company director of maintenance has notified the certificate management office on 3/18/2016 that pratt whitney maintenance facility AMO020-00 has verified intermittent faults with the suspect tscu sn: MM0152 at initial bench testing that might coincide with the identified fault, and further teardown and evaluation will commence.
As the FAA filed it
ON 02/21/2016, AT APPROXIMATELY 13:20 EST, A COMMUTAIR DHC-8-202 AIRCRAFT FLYING AS UNITED EXPRESS FLIGHT 4944 EXPERIENCED A LEFT ENGINE FAILURE AND ASSOCIATED AUTOFEATHER OF THE LEFT PROPELLER UPON TAKE-OFF ROTATION AND INITIAL CLIMB-OUT. THIS EVENT HAD BEEN IDENTIFIED AS A REPEAT OF A SIMILAR INCIDENT ON THIS SAME AIRCRAFT FROM 11 DAYS PRIOR. (SEE INCIDENT AEA0116009)
UPON INVESTIGATION BY THE COMPANY, AND DETAILED TROUBLESHOOTING OF THE LEFT ENGINE AUTOFEATHER SYSTEM, IT WAS DISCOVERED THAT THE #1 TORQUE SIGNAL CONDITIONING UNIT(TSCU) IS THE PROBABLE FAILING COMPONENT FOR THIS DISCREPANCY, AND THAT THE PRIOR REPLACEMENT OF THE #2 TSCU ON 2/10/2016 MAY HAVE BEEN INAPPROPRIATE CONSIDERING THE SYSTEM OPERATION PER AIRCRAFT MAINTENANCE MANUAL REFERENCE 61-21-00. BASED ON THIS INFORMATION, THE COMPANY REMOVED THE #1 TSCU AND SHIPPED THE UNIT TO PRATT & WHITNEY FOR TEARDOWN AND EVALUATION. THE RESULTS OF THIS EVALUATION IS NOT YET KNOWN AS OF 3/8/2016.
THE COMPANY DIRECTOR OF MAINTENANCE HAS NOTIFIED THE CERTIFICATE MANAGEMENT OFFICE ON 3/18/2016 THAT PRATT WHITNEY MAINTENANCE FACILITY AMO020-00 HAS VERIFIED INTERMITTENT FAULTS WITH THE SUSPECT TSCU SN: MM0152 AT INITIAL BENCH TESTING THAT MIGHT COINCIDE WITH THE IDENTIFIED FAULT, AND FURTHER TEARDOWN AND EVALUATION WILL COMMENCE.
Other reports on N367PH · 3
Matched to the same aircraft by N-number and date.