Other missions included bombing airfields, gun positions, V-weapon sites (total of nine "Operation Crossbow" missions beginning 20 June), and railway bridges in France in preparation for or in support of the invasion of Normandy in June 1944; striking road junctions and troop concentrations in support of ground forces pushing across France, July–August 1944; hitting gun emplacements near Arnhem to minimize transport and glider losses during the airborne invasion of the Netherlands in September 1944; and bombing enemy installations in support of ground troops during the Battle of the Bulge (December 1944-January 1945) and the assault across the Rhine (March–April 1945).