Boeing B-17 Flying Fortress F-9

Several B-17s were converted into long-range photo-reconnaissance aircraft under the F-9 Flying Fortress designation. The first sixteen were B-17Fs with bombing equipment replaced by cameras, retaining some defensive armament. An undetermined number of further airframes received a similar conversion with different cameras as the F-9A, and some of these, along with more B-17Fs, became the F-9B with further camera changes. The final version, F-9C, was applied to ten B-17Gs. After the war all surviving F-9s were redesignated FB-17.