On 6 November 1939, Major Hannes Gentzen, the first German ace of WWII  with seven victories in Poland led 27 Bf 109 of JGr.102 in a sweep over the Saar River. They found 9 French Hawk H-75A of GC II/5 escorting a Potez 63 in a reconnaissance mission.

The German fighters bounced the French and Gentzen shot down one of the Hawks for his 8th victory.

Nevertheless, this was the sole victory of the Germans who lost 4 Bf 109 shot down with 4 pilots killed. Another 4 Bf 109 crash landed with severe damage, one of them with a wounded pilot.

Gentzen was summoned to Berlin to explain the debacle. The German pilots had been thoroughly defeated losing 30% of their number against a force that was one third the size of the attackers.

The conclusion was that the Bf 109 was notably inferior to the Hawk H-75A. This was true. JGr. 102 was equipped with the Bf 109D which was superior to Polish aircraft but markedly inferior to the Hawk.

The 109D had a 700hp Jumo 210D giving it a 0.289 hp/kg power-to-weight ratio, a max speed of 450 km/h, an initial climb of 620 m/min, a ceiling of 8100m and an acceleration of 4.1 km/h per second.

The Hawk was equipped with a 1050 hp Pratt & Whitney SC3-G, providing 0.399 hp/kg power-to-weight ratio, a max speed of 523 km/h, an initial climb of 820 m/min, a ceiling of 10500m, and an acceleration of 7.9 km/h per second.

The 109D was relegated to sectors where no fighters could be encountered and to night service. All single engine units in front line service would only use the E version which was superior to the Hawk. JGr.102 was removed to reequip with Bf 110s.

Notwithstanding the obvious difference of performance which is factual, we must also say that the French pilots were superbly trained and made the most of their mounts to break the nose of the Germans on this occasion.