units were gathered in the small airfield near Vinon-sur-Verdon, where they began their operational training. As Bréguet 691s were not available yet, the crews flew the Potez 633 light bomber. When they were eventually delivered, the Bréguets were popular with their crews, although the unreliable engines in the Bre 691 affected aircraft availability rates, and undercarriage failures proved especially troublesome. Only in March 1940 were the first combat-worthy Bre. 693s delivered, and there were now five squadrons to equip: GBA I/51, GBA II/51, GBA I/54, GBA II/54, and GBA II/35 (GBA stood for Groupe de bombardement d'assaut – assault bomber squadron), with a theoretical complement of 13 aircraft each. Because of this late delivery, crews were still working up their new machines and developing tactics when the Germans attacked. On 12 May, GBAs I/54 and II/54 performed the Bréguet's first operational sorties, against German motorized columns in the Liège-Tongeren-Maastricht area. German anti-aircraft fire was so devastating that only eight of the eighteen Bre.693s returned. The disastrous results of this first engagement forced the French commanders to reconsider their tactics. Until 15 May, GBA crews performed shallow dive attacks from higher altitude, which resulted in reduced losses, but the attacks had clearly been inaccurate, as the Bréguet lacked a bombsight. On subsequent missions, the GBAs reintroduced low-level attacks, but with smaller formations. As the position of the French and Allied armies grew steadily more desperate, the assault groups were engaged daily, still enduring losses to anti-aircraft fire, but also increasingly to German fighters. In late June, the Armée de l'Air tried to evacuate its modern aircraft to North Africa, out of German reach, from where many hoped to continue the fight. However, the short-ranged Bréguets were not deemed able to cross the Mediterranean. Unlike other modern French types, the Bréguet 690 family saw its combat career end with the Armistice. By this time, 104 aircraft had been lost, and a further 14 were written off in November 1940 (most of these had also been destroyed or damaged beyond repair during the campaign). Out of 205 Bréguets delivered to the Armée de l'Air, 58% were lost. The five GBAs sustained crew casualty rates of around 50%. After the Armistice, the Vichy authorities were allowed to maintain a small air force in mainland France, and its assault bomber pilots flew rare training flights in the Bre.693 and Bre.695. After the Germans occupied all