On 09 May 1944 while piloting a P-51B Mustang on a mission to attack an airfield near St. Dizier, France, LT Blanchfield was shot down by a German fighter aircraft. The Missing Aircrew Report initiated after the remaining aircrews returned to base contained this description by 2nd Lt. Frank Speer:

"Flying line abreast, in No. 3 position to Lt. Blanchfield, we dove (at 1000 hours) onto the airfield, coming over the field in a dive from 200 feet down. I believe Lt. Blanchfield was shooting at a Flak Tower, as was his No. 2. I was shooting at hangers and buildings and didn’t see Lt. Blanchfield get hit, but as I passed the field I saw his plane streaming white smoke and he pulled up to about 3,000 feet, very slowly; on a course of 240 degrees from the field. His jacket was covered with oil which also covered the side of the aircraft. He seemed to have lost both his oil and glycol and the engine was detonating violently as he climbed out of the cockpit, as the aircraft rolled in a half roll to the left. His radio seemed to have been shot out also, but he was using both hands and making signs and seemed to be unhurt. When he left the aircraft it was going about 150 mph and his parachute opened almost immediately. He landed in a small woods but we didn’t stay around to see him get out because he was near a small town and we didn’t want to attract attention to him."

He parachuted to the ground about 1km northwest of Putteville, France - approximately 35 km southwest of the target. The German report of his capture on the same date listed him as as "pilot fugitive".

He was returned to U.S. military control at the end of the war.

Herbert J Blanchfield