On 12 August 1918, the British Army was intending to start a major offensive, but it needed information about the enemy positions. Setting off at dawn, West and his observer, Lt. William Haslam, flying an Armstrong Whitworth FK 8 (serial number C8602), spotted an enemy concentration through a hole in the mist. Avoiding severe ground fire, almost immediately they came under attack from seven German fighter aircraft and West was hit in the leg, and his radio transmitter was smashed.
Continuing to identify his location, he remained under attack and manoeuvred his machine so skilfully that his observer was able to get several good bursts into the enemy machines, which drove them away. Only when he was sure of the enemy's position did he attempt to break off and head for his own lines. He twisted his trouser leg into a tourniquet to stem the flow of blood from his wounds. Unable to make his airfield West landed behind the Allied lines and insisted on reporting his findings despite being in excruciating agony. His left leg had five wounds, one of which had shattered his femur and cut the femoral artery, and had to be amputated.