RAF Atlas: Here are the details of the mysterious military aircraft detail flying over Portsmouth including its size, speed, and its flight capabilities

Residents caught sight of the mysterious aircraft soaring through the air on Monday morning and much of yesterday.

Footage captured it travelling over the city through the cloudy conditions.

Now the RAF has confirmed that it is a Atlas aircraft conducting trial flights over the city.

The plane has been easy to spot given its size – measuring 45 metres long with a wingspan of 42 metres.

First introduced into service in 2013, Atlas aircraft have the ability to carry a 37-tonne payload over 2,000 nautical miles to established and remote civilian and military airfields, as well as short unprepared or semi-prepared strips.

Capable of operating at altitudes of up to 40,000ft, an Atlas plane also offers low-level capability – as seen in its low flights around Portsmouth.

It can accommodate as many as 116 fully-equipped troops, as well as vehicles and even helicopters, with mixed loads including nine aircraft pallets and 54 passengers .

At full speed, the aircraft can reach 741 kilometres per hour.

The Ministry of Defence (MoD) confirmed the plane spotted above the city was an RAF craft used by 206 Squadron, RAF Brize Norton.

A spokesman said: ‘A RAF Atlas A400 callsign Comet 458 aircraft operated by 206 Squadron, RAF Brize Norton, was conducting a trials flight over the south coast.’