By ALPA Engineering and Air Safety Department staff
Air Line Pilot, August 2003, p.5

On June 13, the Association issued ALPA Operations Bulletin 2003-02 to advise pilots about Airbus airplanes equipped with certain engines that changes had been made in FAA-approved operating procedures relating to those engines.

The FAA issued a final rule on May 23 specific to Airbus aircraft operating International Aero Engines (IAE) V2500-A5 series engines. The rule specifies airplane flight manual (AFM) revisions to incorporate new flightcrew procedures to follow if an OIL FILTER CLOG message appears on the electronic centralized aircraft monitoring (ECAM) display in flight. The final rule is in response to several recent engine anomalies on the subject engines.

The FAA had received a report of a recent incident of dense smoke in the cabin on an Airbus A319 that resulted in the pilots shutting down an engine and making an emergency landing. The smoke rapidly filled the cabin and cockpit, reducing visibility to the point that the pilots had difficulty seeing their instruments.

Investigation revealed that the smoke was caused by the failure of the Number 3 bearing on an IAE V2500-A5 series engine, resulting in oil being ingested into the cabin air conditioning system through the engine high-pressure compressor. The ENG 1 OIL FILTER CLOG message appeared on the ECAM display about 10-15 minutes before the smoke filled the cabin; however, no pilot action was associated with this message.

In-service reports have shown that the OIL FILTER CLOG message is frequently a symptom of engine-bearing damage that could lead to smoke entering the cabin through the air conditioning pack on the affected side. This condition, if not corrected, could reduce the flight crew’s ability to see and result in the flight crew’s having difficulty in controlling the airplane while following smoke-removal procedures.

ALPA has learned that during the past 2 years approximately 20 Number 3 bearing failures have occurred on a subset of the subject engines.

In the very near future, the FAA will issue another series of regulatory actions that will address the hardware modifications necessary to reduce the likelihood of an engine failure.

The FAA is recommending, and ALPA agrees with, the following procedure for the flight crew to follow if an OIL FILTER CLOG message is displayed on the ECAM while in flight:

No pilot action is required if an ENG 1(2) OIL FILTER CLOG warning appears on the ECAM. However, to minimize the risk of oil fumes contaminating the air-plane’s air conditioning system, pilots of the affected airplanes should systematically follow the following procedure in any event of oil filter clog:

• Eng Bleed (affected side)—Off (Prevents possible bleed contamination by engine oil.)

• Pack (affected side)—Off (Switching off one pack enables the remaining pack to operate at 120 percent without any risk of remaining bleed misbehavior. Keep the pack on in case of an MEL dispatch with one pack inoperative. The pack that has been switched off remains available with the crossbleed valve open. Therefore, switch it on in case of a subsequent independent malfunction affecting the operating pack.)

• Crossbleed—Open (Opening the crossbleed valve enables the wing anti-ice to be used when needed.)

• Closely monitor engine parameters for surge/stall, oil pressure fluctuations, or abnormal engine vibrations and, when necessary, follow the associated procedure.

• If, after the OIL FILTER CLOG warning appears on the ECAM, the engine experiences or has already experienced a surge/stall possibly accompanied by a yaw effect on the airplane:

Eng (affected side) thrust lever—Idle (Reducing the thrust of the affected engine minimizes further damage to the engine rotary machinery, but will not necessarily prevent more oil from entering the gas path. Maintain engine at idle, and consider shutting down the engine if high vibration occurs or oil quantity/oil pressure drops low.)

OIL FILTER CLOG warnings appearing on the ECAM while the airplane is on the ground during engine start are frequently the result of low oil viscosity and may be self-recoverable. In the event of an OIL FILTER CLOG warning during engine start, pilots should follow their company’s procedure.

Pilots must coordinate these potential actions with their airlines to ensure compliance with all company procedures.

ALPA members who have any questions or comments about this Operations Bulletin or any other aviation safety matter should contact the Association’s Engineering and Air Safety Department at 1-800-424-2470.