A B747 captain reported losing oil quantity on #3 engine enroute. Sufficient oil remained to operate...

Narrative:

Number 3 engine oil was full on departure. By the time we reached 50W; we had less than 2 quarts remaining. Contacted [operations] as to where we should go in the event of an engine shutdown and determined we had fuel and acceptable weather to proceed to [alternate]. After further consideration and discussion with the fact that the engine was maintaining steady oil pressure and stable oil temperature much longer than we had anticipated; we elected to proceed to our original destination. On approach; the oil pressure started to fluctuate so I elected to secure the engine with the concurrence of my crew so there would be sufficient oil remaining to maintain a positive windmilling oil pressure and prevent further damage. We landed without incident.

Original NASA ASRS Text

Title: A B747 Captain reported losing oil quantity on #3 engine enroute. Sufficient oil remained to operate the engine until approach was begun; at which the time the engine was shut down.

Narrative: Number 3 engine oil was full on departure. By the time we reached 50W; we had less than 2 quarts remaining. Contacted [Operations] as to where we should go in the event of an engine shutdown and determined we had fuel and acceptable weather to proceed to [alternate]. After further consideration and discussion with the fact that the engine was maintaining steady oil pressure and stable oil temperature much longer than we had anticipated; we elected to proceed to our original destination. On approach; the oil pressure started to fluctuate so I elected to secure the engine with the concurrence of my crew so there would be sufficient oil remaining to maintain a positive windmilling oil pressure and prevent further damage. We landed without incident.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	984601
Time
Date	201112
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	B747-200
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Component
Aircraft Component	Turbine Engine
Person 1
Function	Check Pilot
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical

A B747 captain reported losing oil quantity on #3 engine enroute. Sufficient oil remained to operate the engine until approach was begun; at which the time the engine was shut down.