MacArthur accelerated his timetable yet again in September 1944, and brought forward the planned invasion of Leyte to October 1944.[65] That this was the worst time of the year for campaigning on Leyte was not overlooked.[66] Typhoons and heavy rains hampered the efforts to construct and rehabilitate airbases, and without them, large numbers of aircraft could not operate from Leyte. This meant not only that few air strikes could be flown in support of the Sixth Army, but that the Allied Air Forces could not prevent the Japanese from reinforcing Leyte.[67] An additional five Japanese divisions and two mixed brigades were sent to Leyte, and the battle became one of grinding attrition.[68] Able to view his troops in action more often than hitherto, Krueger found much to criticize. He noted that tanks were employed poorly, that the infantry were not aggressive enough, and saw poor sanitation and meals as a sign that officers were not taking adequate care of their men.[69] Krueger's generalship has also been questioned, with Ronald Spector criticizing "Krueger's disastrous decision to delay the push into the mountains west of Carigara in favor of beach defense."[70] Krueger based his cautious appreciation of the situation on various intelligence sources rather than relying solely on Ultra.[71]