Md-11 captain reported loss of engine oil quantity in #3 engine while in-flight.

Attributes
ACN	1683464
Time
Date	201909
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Powerplant Lubrication System
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

Loss of #3 engine oil qty at about 2 hours into flight. Followed QRH (quick reference handbook); good oil pressure and temperature. Per [maintenance control] request we pulled the engine to idle for 2 minutes but no change. Oil not 'hiding.' about 2 1/2 hours we saw a constant decrease in oil pressure. QRH said to keep engine running until oil pressure or temperature abnormal. What defines abnormal in this case? I asked [maintenance control] and [dispatch] how long to keep it running or what is abnormal. I decided to shut it down while pressure was still in the green (100 psi) knowing when we went to idle it would go amber or red. Performed engine shutdown with QRH. Manual landing due to radio altimeter inoperative.

Original NASA ASRS Text

Title: MD-11 Captain reported loss of engine oil quantity in #3 engine while in-flight.

Narrative: Loss of #3 Engine Oil QTY at about 2 hours into flight. Followed QRH (Quick Reference Handbook); good oil pressure and temperature. Per [Maintenance Control] request we pulled the engine to idle for 2 minutes but no change. Oil not 'hiding.' About 2 1/2 hours we saw a constant decrease in oil pressure. QRH said to keep engine running until oil pressure or temperature abnormal. WHAT DEFINES ABNORMAL IN THIS CASE? I asked [Maintenance Control] and [Dispatch] how long to keep it running or what is abnormal. I decided to shut it down while pressure was still in the green (100 psi) knowing when we went to idle it would go amber or red. Performed engine shutdown with QRH. Manual landing due to radio altimeter inoperative.

Data retrieved from NASA's ASRS site 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.