The SCMP story seems to be hinting at "foreign object" on taxiway. The question is, what "foreign object" on the taxiway can cause the tire to explode like that?
South China Morning Post Simon Parry
Airbus tyres explode on Chek Lap Kok taxiway
Airbus plane aborts take-off from Chek Lap Kok after tyres explode
An investigation has been launched after an Airbus plane with 243 people on board was forced to abandon take-off from Hong Kong after four of its tyres exploded, wrecking one of the plane's engines.
The A340 suffered extensive damage in the incident, which happened as it travelled down a taxiway at Chek Lap Kok shortly before midnight on April 1. The Swiss International Air Lines flight was preparing to fly to Zurich.
Debris from the four tyres smashed the cowling of one of the plane's engines and peppered the underside of the plane, forcing the pilot to abandon the flight and call for help to unload its passengers.
The passengers were taken off the stricken plane using a set of stairs driven out onto the taxiway. Some were put on indirect flights to Zurich the following morning, while others waited to catch the same direct flight on April 2.
Airbus and Swiss airline experts have since flown to Hong Kong to join the Civil Aviation Department in an investigation to find out what caused the accident, which the airline said was "serious" and unprecedented in its fleet.
The plane was still in the maintenance area yesterday after having its damaged engine replaced and repairs carried out to the landing gear. It is expected to fly back to Zurich within days.
Investigators are understood to be trying to establish whether a mechanical problem with the landing gear or axles caused the tyres to explode or whether a foreign object on the taxiway might have caused the incident.
A civil aviation spokesman said a 16-metre-long scratch was found on the taxiway. It was believed to have been caused by the wheels scraping on the tarmac after the tyres exploded.
Swiss spokesman Jean-Claude Donzel said the incident was "very strange". "It is the first time we have had an incident like this on a taxiway," he said. "You do occasionally have something like this happen after a hard landing if you have turbulence on your descent, but not when a plane is just rolling down a taxiway.
"The damage was quite serious and we had to replace one engine on the aircraft. Some of our people came from Switzerland to Hong Kong to supervise the repairs. We expect the aircraft to be ready to fly again in the next few days.
"We are looking forward to learning the outcome of the investigation. I don't want to speculate, but obviously we would like to know if there was any object on the taxiway that might have caused this to happen."
The civil aviation spokesman was unable to say if any foreign objects had been found on the taxiway but said the scratch - 10mm deep and 16 metres long - was almost certainly caused by the movement of the aircraft while the tyres were deflated.
"Further investigations are required to determine what happened. The [Civil Aviation Department] will collect all the necessary evidence to support the investigation," he said.
A senior Hong Kong-based Airbus captain described the accident as "extremely unusual". "I can't think of a precedent," he said. "I can only imagine that something external to the plane, possibly something on the taxiway, caused this to happen.
"The plane would only have been travelling at about 30 knots or 40 miles per hour (about 64km/h) while on the taxiway. Tyres are pretty tough these days and if anything goes wrong, they usually deflate. They don't explode. In all my years of flying I have never had a tyre go on me. The explosion would have been pretty powerful. If you were near one of the tyres when it exploded, the flying debris might kill you. But the passengers wouldn't have noticed much."
The incident was stranger for the fact that the engine affected by the flying debris was the No4 engine, not the No3 engine directly above the burst tyres, the pilot pointed out. An Airport Authority spokesman said it had deployed staff to inspect the taxiway after the incident, arranged disembarkation for passengers and facilitated the towing of the aircraft for maintenance. Aircraft movements and airport operations were not affected. "After the completion of the immediate on-site inspection, we found that the scratch did not affect taxiway operations and aircraft safety," he said. "While there is no immediate safety issue, pavement resurfacing for the concerned taxiway will be carried out within two weeks."