Three people have escaped with minor injuries after their light plane crashed on the A40 in Monmouthshire.
It happened about 15:25 BST on Saturday between Abergavenny and Raglan.
Two passengers and the pilot have been taken to hospital. Air accident officials have also been alerted.
The road was closed, with two South Wales fire engines at the scene. Crews believed there were about 120 litres of fuel on board, which was contained as they stopped the leak.