Army Air Forces Statistical Digest,
World War II

Table 196 -- Twentieth Air Force - B-29 Utilization and Maintenance: Jun 1944 to Aug 1945
Month XX Bomber Command XXI Bomber Command
Total Hours Flown Per Plane Per Day Operational Plane Days in Maintenance Per Sortie a Total Hours Flown Per Plane Per Day Operational Plane Days in Maintenance Per Sortie a
Average 3.4 4.4 6.0 2.1
1944
Jun 3.4 8.1 - -
Jul 3.7 4.9 - -
Aug 4.1 7.9 - -
Sep 3.8 5.6 - -
Oct 3.4 3.5 - -
Nov 3.7 4.3 2.2 4.3
Dec 3.4 4.6 4.9 4.3
1945
Jan 3.4 2.6 5.8 5.5
Feb 3.1 2.3 4.6 5.6
Mar 2.5 2.8 8.1 2.4
Apr - - 7.3 2.1
May - - 5.4 1.9
Jun - - 6.2 1.5
Jul - - 6.1 1.7
Aug - - 5.6 1.6

 a Sorties include ferrying and photo flights