Sunday, 11 December 2022

Why Engine Fire Procedure Important ? THE AVIATION


Do not Wait to Apply the Engine Fire Procedure

Several recent engine fire events highlight the importance of timely application of the engine fire procedure.

An A330 aircraft departed for a long-range flight. The aircraft was in CONF 2 for the takeoff. The takeoff roll was normal, but the ENG 2 FIRE red ECAM alert triggered (T0) 17s after liftoff. The flight crew continued the climb. The engine display showed stable engine parameters for both engines.

At T0 +51s, the aircraft reached 2400 ft RA. The PF set the engine 2 thrust lever to IDLE and pushed the engine 1 thrust lever to TOGA.

At T0 +52s, the PF set the engine 1 thrust lever to MCT and this caused the autothrust to engage in thrust mode.

At T0 +2min 27s, the flight crew set the engine 2 master lever to OFF.

At T0 +2min 43s, the flight crew pressed the ENG FIRE pushbutton and discharged AGENT 1 followed by AGENT 2. The ENG 2 FIRE alert remained after both agents were discharged.

At T0 +3min 38s, the flight crew engaged the autopilot and leveled off the aircraft at 7000 ft.

At T0 +6min 31s, the flight crew started the APU, which provided the electrical power supply to the right side.

At T0 +9min 39s, the EGT indication for engine 2 started to increase, even though it had shown decreasing EGT from the time when the engine 2 master lever was set to OFF.

At T0 +10min 03s, the ENG 2 FIRE alert stopped and the ENG 2 FIRE DET FAULT amber ECAM alert triggered.

At T0 +11min 23s, the ENG 2 EGT OVERLIMIT amber ECAM alert triggered when engine 2 EGT reached 600°C.

At T0 +15min 09s, the engine 2 N1 value became invalid.

At T0 +17min 35s, the engine 2 EGT reached a peak value of 801°C.

At T0 +25min 02s, the aircraft touched down on the runway and safely came to a stop. Smoke and flames coming from engine 2 were seen. The fire brigade arrived and extinguished the fire.

Investigation enabled Airbus to conclude that the most probable cause of the engine fire was a leak from the green hydraulic circuit.

Any red ECAM alert requires immediate action by the flight crew to ensure the continued safety of the flight. When the ENG X FIRE alert is triggered, a red LAND ASAP message appears on the ECAM. This requires that the flight crew land as soon as possible at the nearest airport at which a safe landing can be made.

The detection system for engine fire is composed of dual sensing element loops. They are located in the areas around the engine with the highest fire risk of fire and near compartment air exhausts for overheat detection. These are zones where flammable liquids are present with a potential ignition source, such as the accessory gearbox area, the pylon area above the combustion chamber, the combustion chamber area, and the fan area on certain engines.

The dual sensing element loops are monitored by a Fire Detection Unit (FDU) (A320 family/A330/A340 aircraft), the Fire Protection Function hosted in CPIOMs J (A350 aircraft).