Accident Year – 2016
Captain of the A380-800 received a tyre pressure warning on take-off
Aeroplane flew from Hong Kong to London Heathrow on a 13-hour journey
One pilot said that the tyre probably detached from the wheel on landing
An aviation expert said the shape was a quirk of A380 weight distribution
An astonishing picture has emerged of a square-shaped tyre on a British Airways A380 that touched down at London’s Heathrow Airport.
Aviation experts have been left baffled by the misshapen deflated wheel, which was part of the landing gear on a flight that arrived.
The Civil Aviation Authority described the incident as ‘curious’, a serving pilot admitted he wasn’t sure how it could have occurred and even an aviation safety expert from the Royal Aeronautical Society said the square tyre was ‘a bit mysterious’.
The captain of the Airbus A380-800 received a loss of tyre pressure warning on take-off.
Following the indication, the crew made the decision to continue the flight and reportedly called ahead to London to request a tow tug as a precaution in case the aircraft could not taxi to the gate under its own power.
After the 13-hour flight the double-deck, wide-body Airbus landed safely on runway 09L and made its way to the gate without assistance.
Both Bridgestone and Michelin who were consulted came to the same explanation:
1. The tire got an FOD damage or puncture that perforated the casing.
2. The tire leaked during the flight until low/zero pressure.
3. During descent, when aircraft reached a lower altitude, due to the fact that either the hole in the tire closed up (due to low pressure inside the tire) or because the size of the hole did not allow the tire pressure to increase as fast as the outside air pressure, the higher outside air pressure exerted an external force on the tire that compressed into this this strange square shape.
This is the same thing with an empty (or almost empty) plastic bottle that would be closed in altitude and that collapse during the descent due to higher ambient pressure.
Airbus is aware of a similar issue on a competitor’s aircraft. Once the tire was removed, it recovered its round shape.
It is to be highlighted that in the both cases, the tires landed fully deflated with no break up or disintegration.
We would like to remind that in such a configuration (landing with a tire fully deflated), the involved wheel and the adjacent one have to be replaced in accordance with the relevant AMM’s instructions.
The reasons for which the tire took this “square shape” are difficult to explain precisely. It is assumed this is connected to the changing stiffness of the belt plies structure, especially as the sidewalls are compressed inwards. A square seems to be an optimum shape.
It must be highlighted that this type of event is relatively uncommon and that in most of the cases the tire will be destroyed during landing due to the pressure loss.
source – Dailymail.co.uk, Av herald.com
