The emphasis of German air attacks switched to bombing Fighter Command bases and its infrastructure. On 13 August 1940, Sperrle's air fleet played a role in the failed "Unternehmen Adlerangriff" ("Operation Eagle Attack"). As night fell, Sperrle sent "Kampfgruppe" 100 (Bombing Group 100) to bomb Supermarine Spitfire factory at Castle Bromwich, Birmingham which failed to achieve anything. Sperrle, Kesselring, Grauert and Loerzer were summoned to Karinhall to explain why the operation has been a mess. At the meeting, it was decided to intensify attacks from all directions, including Air Fleet 5 in Norway, when the weather permitted.