bombing of the defences; Loerzer did not carry out the plan, but a series of bombing operations on the Meuse front. II. Fliegerkorps flew 1,770 missions, Richthofen's command flew 360. The bombing played an important role in allowing the breakthrough at Sedan, while Sperrle's fighters repulsed attempts by the Allies to bomb the bridge on 14 May, following their capture. German air defences accounted for 167 bombers destroyed. During the breakthrough to the English Channel, rail networks were attacked to prevent Allied forces rallying. Greim's V. Fliegerkorps subjected regrouping French forces to heavy air bombardment. From 13 to 24 May, 174 French rail stations were bombed as were 186 localities, while factories were struck on 35 on occasions and airfields 47 times. Guderian's advance tore through the heart of ZOAN's area and AASF's infrastructure threatening the western airfields of ZOAE. The British abandoned France on 19 May, a day before the German army reached the Channel at Amiens. Sperrle's subordinates, Richthofen and Greim lost 47 reconnaissance aircraft in five days in a bid to find targets. By this time, Sperrle's boundary with Kesselring ran down the Sambre to Charleroi. Sperrle's job was to protect Guderian's southern flank, though he was ordered to assist against an attempted counter-attack near Arras by supporting the 4th Army advance north. Grauert's I. Fliegerkorps contributed to 300 sorties over Arras. Loerzer and Greim protected Guderian along the Aisne, the former supporting the 2nd and 12th armies. Sperrle's subordinates flew only seven operations against airfields from 20 to 23 May, but 54 against rail stations and another 47 against localities. Sperrle and Kesselring objected to the halt order during the Battle of Dunkirk. Neither man believed the pocket could be reduced by air power alone. Sperrle, according to Richthofen, was ambivalent and had made few provisions for an attack on the port, preferring to concentrate on his area of operations in the south. Richthofen and Kesselring argued their commands had suffered heavy losses and were in no position to gain air superiority. The campaign began promisingly when Grauert and Loerzer assisted in the bombing and destruction of the inner harbour forcing Allied shipping to use the poorer outer harbour. On 26 May, the chiefs of staff of I., II., V. and VIII. Fliegerkorps met at Château de Roumont, near Ochamps, with Sperrle for a conference on coordination issues. ULTRA at Bletchley Park intercepted Richthofen's signals and