Flight Crew Air Transport Pilot (ATP)
Troubleshooting
Aircraft Equipment Problem Critical
Flight Crew Returned To Departure Airport; Flight Crew Landed in Emergency Condition; Flight Crew Inflight Shutdown; General Declared Emergency
Aircraft
On climbout; once above low level turbulence we noticed unusual and severe vibrations that appeared to be coming from the engines. We ran the QRH for Unusual Engine Vibrations which enabled us to isolate the problem to the #2 engine. The QRH then instructed us to proceed to the Engine Shutdown Checklist which was completed as well. At this point we declared an emergency with ATC and were turned direct back to the departure airport for an emergency landing. We notified the Flight Attendant of the situation; that we would be making an emergency landing and the approximate time to landing. We then called Operations; informed them that we were an emergency aircraft returning and asked them to let Dispatch know. The passengers were then told about the situation; that the aircraft flies just fine on one engine and that we would be landing shortly. ATC brought us immediately back [landing]. We shot the visual approach and landed without further incident. After exiting the runway the emergency vehicles met us and inspected the aircraft for damage or fluid leaks before allowing us to taxi to the gate under our own power. We returned to the gate and deplaned the passengers. A brief inspection of the number #2 engine led to the discovery of a loose prop blade.
[No additional information was provided in narrative 2.]
An SF340 developed a number 2 engine vibration after takeoff so the engine was shutdown; an emergency declared; and the flight returned to the departure airport.