Q400
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
During the initial climb I noticed the Number 1 engine oil pressure fluctuating lower than normal. By 1;500 FT HAT it became apparent that it was trending below the green arc. All other engine indications were normal. For a bit the oil pressure seemed to settle down in the green arc and we thought it might have been an abnormality with the oil pressure indication. We decided to be on the safe side and return to the field just in case. We advised ATC that we'd like to return; but at this point no emergency existed. ATC turned us to a downwind and we started preparing for landing. We made a quick PA to advice of the precautionary return and also let the flight attendants know. We reviewed the Low Oil Pressure checklist. Just about the point ATC started turning us on base leg for landing the oil pressure started trending down again; this time well below the green arc. We decided to actually run the Low Oil Pressure checklist which leads to feathering the prop. Because the pressure was not below 44 PSI; we did not shut down the engine. Because of the compression of time; we did not run the single engine landing checklist. An uneventful landing was performed and we were able to keep our taxi speed such that I felt fine clearing all runways and taxiing to the gate.
A Q400 Captain reported low Number 1 engine oil pressure that led to feathering the prop and returning to departure airport.