Spitfire Mk1a X4650 at Biggin Hill, part of  the 75th anniversary of the “Hardest Day” in the Battle of Britain.

Spitfire Mk1a X4650 at Biggin Hill, part of the 75th anniversary of the “Hardest Day” in the Battle of Britain.

Spitfire Mk1a X4650 at Biggin Hill, part of  the 75th anniversary of the “Hardest Day” in the Battle of Britain.

Spitfire Mk1a X4650 at Biggin Hill, part of the 75th anniversary of the “Hardest Day” in the Battle of Britain.