Over the past eighteen months of inconclusive attritional engagements, Fighter Command had established a measure of air superiority within range of its fighters. Day incursions into British airspace had dwindled to the occasional pair of German fighter bombers racing across the Channel, dropping their bombs and racing back. At 06:15 on 7 July, two ships in the Solent, with troops for Rutter on board, were hit but the bombs failed to explode and passed through their hulls, causing only four casualties. German photographic reconnaissance was much more difficult, because adequate results required the aircraft to fly a set course and height. Repeat sorties once or twice a week were ideal for comparative analysis of photographs but the could manage only one set of pictures a month. A partial reconnaissance was obtained from 28 to 31 July, after Rutter had been cancelled and not again until 24 August, five days after Jubilee. The air plan was to exploit the raid to force the to fight on British terms and suffer a serious defeat; Air Vice-Marshal Trafford Leigh-Mallory, the commander of 11 Group Fighter Command was to command the air effort, for which 56 fighter squadrons, comprising Spitfire fighters, Hurricane fighter-bombers and Typhoon low-level interceptors. Four Mustang Mk I squadrons of Army Cooperation Command were provided for long-range reconnaissance and a contingent of five bomber squadrons were to participate for smoke laying and tactical bombing. The landings could be expected to prompt a maximum effort by the in Northern France, Belgium and the Netherlands, with about 250 fighters and 220 bombers.