British Airways Airbus A380 left Hong Kong on May 5 with 22 round wheels but after a 13-hour trip, it arrived on London's Heathrow Airport with one square tyre that confused aviation experts on how it happened.

The bizarre occurrence was seen in a photo posted on The Aviation Herald, which reported that the crew received a "tyre pressure indication" during their departure from Hong Kong. Despite that, they decided to proceed to London and requested for a tow tug to ensure safe landing.

Fortunately, the aircraft was deigned to land safely with a deflated tyre which allowed it to land at Heathrow without assistance but with one deflated tyre. Upon landing, engineers immediately responded by changing the tyre.

Aviation experts admit that the phenomenon is strange. A spokesperson from the Civil Aviation Authority said that "it's a curious one" and that he has "not seen anything like it before."

Meanwhile, Kumar Mysore, Royal Aeronautical Society aviation safety expert said that the phenomenon was "a bit mysterious" but he provided an explanation to give light on the incident.

Mysore said that it is possible that the tyre had four edges when the deflated round tyre rotated on the flat ground. Hence, it occurred after the aircraft stopped. He added that the square shape also has to do with the way the weight of the A380 is distributed onto the wheels, CNN reported.

"The effect of the weight on the deflated tyre is the same as when you squeeze a rubber ring toy with different intensity, it can turn into a different shape," Mysore said, according to Daily Mail. "In an A380, for this particular situation, it happens to be squarish. In a 747, for instance, the load of the aircraft does not give rise to this particular shape."

"The reason for the deflation could have been overheating brakes over-pressurising the tyre and making it burst - though that's unlikely as the pilots receive a warning if the brakes are too hot - or a foreign object on the runway at Hong Kong cutting into the tyre. In all these cases pilots are well trained to handle the situation safely," he added.