C-GLQQ, a Bombardier DHC-8-400 aircraft operated by Porter Airlines, was conducting flight
POE122 from Newark/Liberty Intl (KEWR), NJ to Toronto/Billy Bishop Toronto City (CYTZ), ON with 4 crew members and 27 passengers on board. As power was reduced once the aircraft reached its initial cleared altitude of 14 000 feet after the departure from KEWR, the flight crew noticed an unusual noise coming from the engines. Simultaneously, a POWERPLANT message was received, which prompted the flight crew to execute the QRH. In the absence of abnormal engine indications, the flight crew continued to monitor the situation, and contacted the operator’s maintenance via ACARS. Following a step climb to FL180, the number 2 Propeller Electronic Control (PEC) caution light illuminated, and the number 2 propeller RPM rose to 1060. The flight crew executed the QRH one more time, shut the number 2 engine (Pratt & Whitney Canada PW150A) down, declared an emergency, and elected to divert the aircraft to WilkesBarre/Scranton Intl (KAVP), PA where it landed without further incident with ARFF standing by. Following an inspection, the aircraft taxied to the terminal building.
Maintenance personnel determined that the number 2 Beta Feedback Transducer (BFT) failed, causing the propeller to initially go into an underspeed condition, followed by an overspeed condition. It was held at higher than normal propeller speeds (1060) by the Over Speed Governor (OSG) until the flight crew shut the engine down. The incident has been entered into the operator’s Safety Management System for further investigation.