B767 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 160; Flight Crew Total 21000; Flight Crew Type 7200
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Declared Emergency
Aircraft
While on crew rest on the second break; I was awakened by a flight attendant and informed that I was needed on the flight deck. My first officers then informed me that they were dealing with a complete loss of indicated oil quantity on the left engine. We were in level flight at FL350 Center was on the VHF; and Dispatch and Maintenance Control were on the Satcom. Both engines were producing normal power. The left engine was indicating zero oil quantity; normal oil temperature and low oil pressure. With two of three engine indications abnormal; the consensus was to put the aircraft on the ground. I made the decision that ZZZZ was the safest airport under the circumstances. We discussed this with Dispatch and then received clearance directly to ZZZZ from Center. As [a company flight] was very near our track; I elected to get on the airway for collision avoidance. As we proceeded to ZZZZ; Maintenance Control asked if we could see what would occur if we reduced thrust on the left engine. As we were experiencing normal engine thrust at this point; I elected to delay that determination until top of descent. Enroute; the left engine oil pressure was slowly decreasing towards the minimum 80 psi. As we approached top of descent; the left engine oil pressure was very close to the minimum 80 psi. It was quite possible that we would be landing on one engine and therefore elected to declare an emergency. We retarded both throttles to idle and began down. At that time; the left engine oil pressure dipped below 80 psi and the red warnings illuminated. We found that if we advanced the left throttle slightly; we could keep the oil pressure out of the red. By doing this; we avoided shutting down the engine. We completed a normal approach and landing. After landing; we observed the red warnings and shut down the left engine. We taxied to the ramp on the right engine and completed the shutdown.
B767 Captain on break is informed that left engine oil quantity is zero; with slightly low pressure; and normal temperature. The decision is made to divert to the nearest suitable airport and the crew is able to land with both engine operating. An obvious oil leak is detected on post flight.