operational strength to 120 fighters and were alerted an hour before the German bombers got airborne. The operation inflicted minor damage. On 5 June Sperrle's forces flew eight bombing operations against railways and localities, 21 to 31 against road targets, 12 against troop columns and 34 to 42 against French Army defences or strongpoints. II. Fliegerkorps alone flew 276 bombing missions. On 12 June, as the French front collapsed, Sperrle planned a new assault upon Paris, but it was declared an open city before it could be carried out. Sperrle was ordered to support Rundstedt advancing southward, with orders to encircle the Maginot Line, from the west. Luftflotte 3 carried out bridge interdiction operations in the Loire and on 17 June Guderian reach the border with Switzerland completing the encirclement. The campaign played out for a further five days, which came as Luftwaffe logistics were breaking down—fuel and ammunition shortages were acute and relied on air transportation. Sperrle attempted to prevent the British Operation Aerial—a second evacuation—but the only success was the sinking of Lancastria, with 5,800 lives lost. On 20 June arrangements were made for the Armistice of 22 June 1940. Upon learning of it, Sperrle ordered the abandonment of a planned bombing operation against Bordeaux. At 21:00 on 24 June Sperrle ordered that Luftflotte 3 cease operations by 00:35 the next morning. In the 1940 Field Marshal Ceremony Sperrle was promoted to the said rank. Battle of Britain In July 1940 Winston Churchill's government rejected peace overtures from Hitler. Hitler resolved to knock Britain out of the war. The OKL began tentative planning for Operation Eagle Attack to destroy RAF Fighter Command to gain air superiority, before supporting an amphibious landing in Britain, codenamed, Operation Sea Lion. Sperrle thought the RAF could be defeated en passant. His personal strategy to attack ports and merchant shipping was overruled by Göring, ostensibly because the ports would be required for the invasion. Kesselring's contemporary notes indicate he thought air superiority could only be attained for a short time, since most airfields and factories in Britain were out of range. Sperrle and Kesselring miscalculated, or were misled by intelligence, into underestimating the number of fighter aircraft available to Fighter Command—they put the RAF total at 450 aircraft when the real figure was 750. Chronic intelligence failures on British production, defence systems and aircraft performance inhibited the German air operation throughout the battle.