A350 Crash Ignites Debate About Composite Materials.

Yesterday's crash (2nd January 2024) of the landing Japanese Airlines Airbus A350 resulted from a collision with a Japanese Coast Guard Bombardier DHC8-300 on the ground. How the two-engined turboprop came to be in the way of the A350 will now be the subject of an investigation.

“Having responded to four plane crashes, I can attest to passengers taking unnecessary risks even when the plane is on fire. Realising he’d left a bottle of whiskey behind, a passenger reentered the smoldering wreck awash with leaking fuel. ”

Passengers flee the A350 - as its left wing burns.

Fortunately, all the passengers and crew exited the plane, although five of the six crew on the Coast Guard plane were not so lucky. Total praise must go to the JAL crew for getting all passengers off. Remarkably, the A350 remained intact despite such a violent collision.

According to FlightRadar24, the approach of the A350 was standard, as shown below, with the plane reportedly cleared to land by ATC.

Following the collision, the A350 immediately caught fire as it travelled some distance down the runway before coming to rest.

Having responded to four plane crashes, I can attest to passengers taking unnecessary risks even when the plane is on fire. During the China Airlines MD-11 crash at Chek Lap Kok in August 1999, one passenger exited through a split in the fuselage of the inverted plane.

Realising he'd left a bottle of whiskey behind, he reentered the smoldering wreck, awash with leaking fuel, grabbed his whiskey and left. He later offered me a swig from the bottle as he regaled the story to an attentive audience in the holding area. I politely declined.

What struck me about the A350 crash was that emergency crews took three hours to extinguish the fire and eight hours to cool the burnt-out airframe.

This long burn time will again raise questions about composite materials in modern passenger jets; the A350 comprises 50 per cent carbon fibre held together with resin. The physical robustness of the structure is evident from this incident. Nonetheless, the fire issue is worth reviewing.

The first fire involving a composite material aircraft was a US Air Force B-2 Stealth bomber in February 2008. That incident resulted in a total hull loss after the plane crashed and burned for six hours. Firefighters arrived within three minutes, with four fire trucks and 53 firefighters fighting the blaze for six hours. It took two days to cool the wreckage.

It took two days to cool the remains of this B-2 Steath Bomber

The US Air Force concluded that the "length of time needed to extinguish the fire and cool the aircraft was unexpected." A detailed report is here.

There are two recorded fires on Boeing 787s, another composite aircraft. A JAL plane parked at the Boston airport had a faulty battery that ignited. Airport firefighters struggled to extinguish the fire, although the aircraft hull survived and remains in service.

In the second incident, an Ethiopian 787 parked at Heathrow, London, suffered a short circuit. A pinched wire in the emergency transmitter deacon on the top of the fuselage proved the cause. The plane soon returned to service.

Hence, the JAL A350 incident is the first total hull loss to fire of a composite airliner.

That the passengers and crew had enough time to escape is a testament to the crashworthiness of the design. Moreover, that only three of eight emergency slides could be used and still everyone got off is remarkable. Full marks to the crew and their training.

Yet, given the duration and intensity of the fire, any trapped passengers are unlikely to survive. For sure, the investigation will re-visit and explore how best to fight fires on composite material aircraft.

Composite airframes are stronger than traditional metal designs. Hence, penetrating the hull to get firefighting water and form inside the cabin is more challenging. A standard metal aircraft requires 5,000 psi to punch a hole in the skin. A composite hull can require up to 8,000 psi, which means changes to airport firefighting appliances. Whether this was an issue at Haneda is not known.

A related point is possible site contamination. Burning composite material produces highly toxic smoke fibres akin to asbestos. Making the crash site safe for investigators and clean-up crews could be challenging.

Yet, it's important not to rush to conclusions until all the facts are known. After all, modern passenger aircraft are designed and built with fire prevention and fire management at the fore. Therefore, the A350 incident should provide valuable insights to help make planes even safer.

“That only three of eight emergency slides could be used and still everyone got off is remarkable. Full marks to the crew and their training.”