Because of the U.S. embargo on arms exports after the beginning of the war, many aircraft were impounded for two months before being shipped to Europe. When the Battle of France began, there were only four "Groupes de bombardement" (bomber squadrons) equipped. The "Glenns" were quickly sent to the front lines where they performed well with their adequate speed and excellent manoeuvrability for an aircraft in this class. In about 400 sorties, they suffered a 4 per cent loss rate, much better than the 16 per cent endured by LeO 451 crews against similar targets.