Date: 202011
Local time of day: 1201-1800
Location: ZZZ.ARTCC, US
Aircraft: A321
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Confusion; Human-Machine Interface; Troubleshooting
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Inflight Shutdown; Flight Crew Landed in Emergency Condition
Contributing factors: Aircraft; Manuals
Primary problem: Aircraft

Narrative: The crew departed ZZZ on time after calling maintenance to reset a Rudder Trim Limiter ECAM malfunction. Pushback; start; taxi; takeoff and climb out were uneventful. Passing FL260 for a cruise altitude of FL270 the First Officer (Pilot Monitoring) identified a flashing oil quantity advisory reading and a low oil pressure indication on the #1 engine system display. Due to the aircraft's momentum and vertical rate of climb the Captain (Pilot Flying) elected to level off at FL270 as planned. Initially the zero oil quantity and low 60 PSI pressure indication were not accompanied by an ECAM message and system status indicated normal. Within a couple of minutes a series of intermittent ECAM cautions and warnings occurred leading to an engine shutdown condition. The amber ENG 1 OIL LO PR Caution illuminated first on the ECAM display. The crew responded by initiating the company non-normal checklist strategy. The Captain announced 'my aircraft' then the First Officer verified that the ECAM was not a Quick Action or ECAM exception item. The Captain elected to remain flying and also took control of the radio. It was a crew awareness only caution so the FO (First Officer) then checked the QRH for follow up items. This Caution does not direct the crew to adjust thrust settings. During this process the caution [message] cleared itself without any inputs from the crew but the zero oil quantity and 60 PSI indications remained. At this point the ECAM display was clear and system status indicated normal. Shortly thereafter the red ENG 1 LO PR warning illuminated on the ECAM display. This occurred intermittently 3 times and then cleared itself each time resulting in a normal system status display on the ECAM. Oil quantity remained at zero and pressure was now steady at 40 PSI on the system display. These intermittent ECAM warnings lasted for approximately 2-3 seconds and then cleared to a normal status for roughly the same amount of time. The next time the ECAM warning illuminated it remained steady and the crew followed the ENG 1 LO PR warning procedures and shutdown the engine. The crew notified Center and requested a radar vector descent to final for the engine out approach at ZZZ1. The non-normal indications initially occurred just prior to the ETP (equal time point) between ZZZ and ZZZ1. However by the time the ECAM directed engine shutdown the flight had progressed passed the ETP and was at a normal descent point for ZZZ1. Dispatch was called using the iPad crew phone and notified of the nature of the emergency and decision to land at ZZZ1. The flight attendants and passengers were briefed about the Precautionary Landing at ZZZ1 and the possibility of airport fire vehicles near the aircraft. After shutting down the engine and notifying ATC; the crew requested and was given a vector and descent direct to a left 10 NM base at ZZZ1. Descent and approach were very stable and normal. The Captain flew the descent and approach with both the autopilot and auto thrust on. Crew requested ARFF (airport rescue fire department) for the landing and cleared the runway for a brief inspection of the engine. On request of the crew the fire department followed the aircraft to the gate. Shutdown at the gate and passenger deplaning were normal. Note: ATC handling by ZZZ Center; ZZZ1 Approach and Tower were outstanding. Handoff from Tower to ARFF at ZZZ1 was seamless and well coordinated. Flight Attendant performance was also outstanding and the passengers remained well informed throughout the emergency. Although oil fault indications were somewhat intermittent and erratic the fact that multiple independent sensors indicated a problem caused the crew to shutdown the #1 engine when directed by the ENG LO PR Warning ECAM. After the flight; maintenance personnel initially reported normal engine oil quantity on a sight gauge even though the engine instrument remained at zero. Initially crew suspects a partial blockage or pump failure in the system without oil loss. The engine oil quantity and pressure indications were initially both alarming and confusing. As the adrenaline level increased for the crew due to the perception there would be an engine shutdown there was also a level of doubt that the indications were accurate. Low oil pressure on the engine instrument should be accompanied by a Low Pressure ECAM Caution or Warning. Why did the pressure remain steady in the amber range with zero on the quantity? This is an uncomfortable situation because our training does not address multiple oil failures without ECAM warnings. It puts the flight crew into one of those gray areas where a Captain is expected to make a decision based on the information he has on hand in a situation not covered in training. The natural instinct of a pilot is to shutdown an engine before complete oil loss to prevent a catastrophic failure. In this occurrence engine indications identified a problem well in advance of ECAM warnings. Yet crew training and aircraft procedures generally do not address engine shutdown without ECAM warning checklist direction. Should crews be given shutdown discretion in the absence of ECAM warnings and checklist? In this situation the Captain elected to continue as the Pilot Flying while the crew worked through the non-normal checklist strategy. Even though most aspects of company's non-normal strategy were performed correctly the overall pace and structure were hampered by the Captain continuing to fly. In this case the checklist strategy would have been better managed if the Captain had delegated flying to the FO. For example; when the ECAM directed the 'Engine Master Switch-Off' both pilots confirmed it was the #1 engine but the Captain positioned it to off. Procedure dictates that the non-flying pilot position the switch to off.




Synopsis: Air Carrier Captain flying A321 aircraft reports low engine oil pressure inflight.