British Airways flight declares mid-air emergency after sudden descent and U-turn over Ireland

It made a sudden U-turn

It comes after the plane squawked 7700, the internationally recognised code for a midair emergency.

Flight BA259 is being operated by a Boeing 777-200ER and was meant to be heading to Chicago O'Hare International from London Heathrow Airport, before it made a sharp turn over Ireland at around 12.50pm this afternoon (Monday, 5 October).

Flight data shows the plane descended around 9,000ft in a few minutes before it turned near Knock in County Mayo.

It is currently the most tracked plane in the world with almost 30,000 people following on Flightradar24.

The plane headed by the south of Ireland before flying over Pembrokeshire, in what looked like a routine return to Heathrow Airport.

However, the plane turned again over Swindon, where it headed down to Dartmoor National Park, before turning north west towards Pembrokeshire.

The plane's tracked route. Image: Flightradar24 screenshot.

The plane then did a U-turn where it headed back towards Dartmoor, before once again heading towards Pembrokeshire - it has this pattern twice so far.

According to simpleflying.com the plane, registered G-VIIA, is the oldest aircraft in the British Airways fleet, having been delivered to the airline in July 1997.

A British Airways 777-200ER. Image: Adobe Stock.

It was also the first ever 777-200ER to roll off the production line.

The Mirror report that the plane is currently in a holding pattern, where it is dumping fuel.

This is a safety precaution, as planes intend to land much lighter than at take off, having normally burnt fuel by time of arrival.

British Airways has not commented yet.