Dash 8-200
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; Flight Crew Inflight Shutdown; General Declared Emergency
Aircraft
We took off normally; Upon reaching acceleration height I (PF) called for 'flaps up; set climb power; climb checklist' The PM brought up the flaps and turned the bleeds on and max; and the ECU to MCL. As she turned the aux pump off the number one engine auto-feathered. We ran the memory action items and looking at the gauges realized what happened and ran the engine failure/fire checklist and shut the engine down. We declared an emergency with Departure and asked to go back. We tried to contact dispatch a couple of times but could not reach them. We had another company aircraft in the area who was able to relay the information to dispatch. They gave us an immediate turn back to the airport for vectors to the ILS. We asked for delay vectors to finish all our checklists. Upon completion of all required checklists we informed Approach we were ready to come in. They gave us vectors for the approach and we proceeded to do the single engine ILS approach. We landed normally and taxied into the ramp and shutdown with no other further incident. Not aware of why the engine auto-feathered after acceleration height.
DHC8 Captain experiences an auto-feather at acceleration height as the Electronic Control Unit (ECU) is switched to Maximum Climb Power (MCL). The engine is shut down and the flight returns to the departure airport.