In the wake of a dramatic incident where all 379 passengers and crew aboard a Japan Airlines jet miraculously survived a crash into another plane at a Tokyo airport, experts have been scrutinizing the factors that contributed to their remarkable escape, with a focus on low fuel levels that potentially prevented a catastrophic explosion.
Collision at Haneda Airport
The incident occurred at approximately 5:45 pm on a Tuesday evening when JAL Flight 516, an Airbus A350-900 departing from Sapporo, collided with a coast guard plane while landing at Haneda airport. Tragically, this collision claimed the lives of five out of the six individuals on board the smaller Dash 8 aircraft.
Narrow Escape from a Fiery Inferno
Despite the plane being engulfed by flames, the most crucial aspect was that it did not explode upon impact. However, the fire quickly spread throughout the aircraft, and it took authorities nearly three hours, until 8:30 pm, to extinguish the blaze.
Materials and Fire Performance
The Airbus A350 involved in the incident featured carbon fiber composites, known for their flammability. Yet, experts believe that the materials used were not the primary factor in the fire’s intensity. Aviation engineers have increasingly incorporated carbon fiber composite materials to reduce weight and enhance efficiency in modern aircraft. Approximately 50% of the A350 is constructed from carbon fiber reinforced polymers, including the wings and fuselage. While these materials can affect fire performance, it’s essential to note that the overall outcome was not significantly influenced by them.
Temperature and Combustion
Dr. Sonya Brown, a senior lecturer in aerospace design at the University of New South Wales, explained that while carbon fiber composites start to lose stiffness at around 200 degrees Celsius, aluminum melts at approximately 700 degrees Celsius. The fire witnessed on the A350’s fuselage reached temperatures above 1000 degrees Celsius, making the materials’ differences in combustion less impactful.
Fire Containment and Evacuation
Brown emphasized that the fire was contained primarily in the left wing, likely due to firewalls designed to withstand high temperatures, preventing flames from spreading to critical areas such as engines and fuel tanks. This containment allowed all passengers and crew to evacuate safely.
Factors Influencing Fire Intensity
The intensity of the flames was also influenced by the plane’s contents. While the evacuation process ideally takes 90 seconds, it likely took longer due to the inability to use the doors above the wings. Additionally, the fire’s duration was prolonged by various factors, including the presence of batteries, electrical systems, and potentially flammable cargo.
Low Fuel Levels as a Critical Factor
One critical factor that may have contributed to averting a catastrophic explosion was the relatively low amount of jet fuel the plane was carrying upon landing. According to Neil Hansford, an industry consultant at Strategic Aviation Solutions, commercial aircraft typically operate with the fuel needed for the trip plus a 10% buffer for efficiency. In this case, the plane carried the trip fuel, the 10% buffer, and extra fuel to reach the alternate airport in the flight plan, which was likely Tokyo’s Narita Airport. This minimized the intensity of the fire and potential for an explosion.
Interior Design and Fire Mitigation
Despite the exterior of an aircraft potentially burning over time, aircraft interiors are meticulously designed to delay the spread of flames, allowing for a safe evacuation. Seats are made from fire-resistant materials, contributing to passenger safety in emergencies.