On this day, 31 May 1944 the 15th USAAF dispatched 480 4-engine bombers and with them an escort of 240 fighters targeting the Concordia Vega oil refinery. The Jagdwaffe sent some 50 fighters from III./JG 77, I./JG 53 and JG 301's 6. & 10. Staffeln to intercept the raid.

According to the USAAF report "in defense of the target the enemy added smoke screens to his aggressive fighter resistance and flak concentration ..". In all the Germans claimed 10 4-engine bobbers and 4 escorts for an own loss of 12 aircraft. In fact the USAAF lost a total of 12 B-24 bombers and with them an another two P-51s and two P-38s matching the Jagdwaffe claims this day.

One of the hardest hit units this day was the "Wilde Sau" night figther unit 10./JG 301 who lost five aircraft and with them two pilots killed. One of the pilos killed in the10th Staffel this day was Fw. Fritz Gehrmann, an accomplished well trained pilot with a the large number of flights, over 1 270, and with hundreds of hours spent at the controls of a variety of machines.

However this day this "wild sow" pilot was to be committed by day on his first sortie and falling victim to a highly trained, aggressive and numerically superior enemy. When Fw. Gehrmann running into a gaggle of aggressively flown P-51s while attempting to locate the bombers, he stood little chance. His Bf 109 G-6 "Black 8" WNr. 20144 was shot down over Ciocanesti, north-east of Bucharest.

Shot down in his first combat sortie he was killed in the subsequent crash. His Staffelkapitän Oblt. Dr. Hans-Günther Kretschmer was also shot down in the same action in "Black 5" WNr. 412236, but was lucky to escaped with injuries.