Date: 201602
Local time of day: 0601-1200
Location: EINN.Airport, FO
Flight conditions: VMC
Light: Daylight
Aircraft: Widebody; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise; Final Approach
ATC / advisory: Center EGGX
Aircraft component: Lubrication Oil
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Distraction; Situational Awareness; Confusion
Second reporter function: Pilot Flying; First Officer
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Landed in Emergency Condition; General Maintenance Action
Contributing factors: Aircraft; Human Factors
Primary problem: Human Factors

Narrative: Oil leak on left engine. At 30 west I noticed oil was down to 3qts. Monitored and just past our second critical point oil went down to 0 qts. Oil pressure stayed ok for about 40 minutes and then started going down from 60 psi to 35 psi. Ran engine at idle during last 30 minutes and made it to SNN airport with both engines running. While diverting into EINN the FO was flying and we were cleared for the approach ILS 06 outside of Elpom at 3;000 feet. Approach mode was armed and we got a LOC capture but it was a couple miles left of the magenta line. I was trying to figure out why we were left of course on the localizer but not on the extended centerline. The glide slope captured and the FO followed it down to about 2;000 feet and I didn't notice. We received a terrain warning. We immediately climbed back to 3;000. ATC also advised us of the low altitude. Rejoined the real localizer and followed it to a landing that I landed. I believe we captured a false localizer and glide slope for some reason. Maintenance had just fixed a leak in Houston before flight. 21 quarts added.


Second narrative: This flight was around 5 hours late because of a left engine oil leak. I was called out on short call and asked to be at the airport as soon as I could make it. I was on my break; it was the second break of the flight. When I came back in to the flight deck I was told of the situation of an oil leak. The oil quantity was indicating 1 quart we were approximately at N51W30. At around XB30z. The captain decided to divert to SNN do to the fact that the oil quantity had gown to zero and we were about 4 hours from [our destination]. As we made our way to SNN the oil pressure kept dropping to around 30. We reviewed the engine shut down procedure in case it would be necessary to shut down the engine. We were on a constant descent from FL370 and were told to fly direct to LUPOR which is part of the LUPOR 2E arrival. From there the arrival takes you to ELPOM which is part of the ILS 06. Prior to reaching LUPOR we were given a clearance to descent to 3000 and clear for the ILS. We selected 3000 on the altitude window and I selected the approach mode. During all the descent the auto pilot was on and on the flight director. I noticed that the glide slope was captured and that the localizer was also coming in. As we descended on the ILS we descended below 3000 feet. Almost simultaneously ATC told us to maintain 3000 feet and to check our altitude and the terrains caution was heard. I immediately added power; the captain stowed the speed brakes and I climbed back to 3000 feet. We recapture the glide slope and sometime later the captain took the controls as previously briefed and continue a stabilized approach. We landed at SNN with both engines and tied to the gate with no engine abnormalities other than a low oil pressure. Although the oil pressure kelp fluctuating between 50 and 30 it never got lower than that and so never got a Master Caution.


Synopsis: While diverting to EINN with an engine oil leak and on the ILS Runway 6; air carrier flight crew captured a false ILS signal; descended on the glide slope; and received a terrain warning.