What happens when an engine of a airplane catches fire while in flight?

The plane's left engine exploded and burst into flames just 15 minutes after takeoff from Helsinki-Vantaa airport on Saturday

Photo: Daily Mail

When an engine of a commercial airliner catches fire while in flight, it poses a critical situation that requires immediate attention and appropriate actions from the flight crew. Engine fires are a rare occurrence due to stringent safety measures and advanced fire protection systems implemented in modern aircraft. However, it is crucial to understand the procedures and consequences associated with such incidents to ensure the safety of passengers and the successful resolution of the situation.

Detection and Extinguishing of Engine Fires

The engine fire protection systems on commercial airliners consist of two main components: fire detection and fire extinguishing. Fire detection is achieved through linear pneumatic sensing systems, commonly known as fire loops, which are gas-filled pipes placed around potential heat sources. These fire loops detect abnormal heat levels, triggering a warning indication to the flight crew. The system incorporates redundancy, allowing for continuous detection even if one loop malfunctions.

In case of an engine fire, modern aircraft are equipped with fire extinguishers specifically designed for engine compartments. These extinguishers contain Halon 1301 or Hydrofluorocompounds (HFCs) and are available for each engine. When activated, the extinguisher's contents are discharged into Zone 1, the engine fan assembly, to suppress fires in that area. For fires in Zone 2, the engine core, the engine is shut down to extinguish the fire. The flight crew follows an engine fire drill, which includes shutting off fuel and hydraulic fluid supplies to the affected engine, reducing the supply of oil, and initiating appropriate actions to isolate the fire.

Response to an Engine Fire

When an engine fire occurs, the flight crew's primary objective is to mitigate the situation promptly and ensure the safety of the aircraft and its occupants. The crew follows established procedures, including activating the engine fire extinguishers, shutting down the affected engine, and isolating fuel, hydraulic fluid, and oil supplies to minimize the risk of fire spread. The crew also communicates the situation to air traffic control and may request priority landing clearance to expedite the aircraft's return to the ground.

Upon successful extinguishment of an airborne engine fire, the flight crew's decision on the urgency of landing the aircraft is not solely influenced by the fire occurrence. However, in the case of severe damage or other factors, the crew may prioritize an immediate landing for precautionary measures.

Timeline and Criticality 

In-flight engine fires demand swift action due to their potential to escalate quickly. According to a UK CAA report, from the first indication of an onboard fire, flight crews have an average of approximately 17 minutes to land the aircraft safely. Therefore, time becomes a critical factor, and prompt response and decision-making are crucial to ensure the best possible outcome.

Safety Improvements and Statistics: It is essential to note that the number of accidents related to engine fires or any other cause has significantly decreased over the years, showcasing the industry's commitment to safety. The statistical analysis of commercial aviation accidents, including data from 2021, indicates a relatively low number of accidents, demonstrating the resilience and safety performance of the aviation industry, even amid challenges like the COVID-19 pandemic.

When an engine of a commercial airliner catches fire while in flight, the flight crew must respond swiftly and effectively. Modern aircraft are equipped with advanced fire protection systems, including fire detection and extinguishing mechanisms, to manage such situations. Prompt activation of fire extinguishers, shutting down the affected engine, and following established procedures are crucial for successful resolution. The timeline for response is limited, highlighting the need for decisive actions. The industry's continued focus on safety and the low number of accidents indicate the effectiveness of safety measures and the dedication to maintaining a high level of safety in commercial aviation.