Heavy losses in the summer and fall of 1943 on deep penetration missions intensified Eaker's requests. Arnold, under pressure and impatient for results, ignored Eaker's findings and placed the blame on a lack of aggressiveness by bomber commanders. This came at a time when General Dwight D. Eisenhower was putting together his command group for the invasion of Europe, and Arnold approved Eisenhower's request to replace Eaker with his own commanders, Spaatz and Doolittle. Ironically, the very items Eaker requested—a larger bomber force, drop tanks, and P-51 fighters—accompanied the change of command and made the Eighth Air Force decisive in defeating Germany using the daylight bombing doctrine.