F-13 42-24621 Yokohama Yo-Yo of the 3rd Photographic Reconnaissance Squadron, 11th Photographic Reconnaissance Group
The Boeing B-29 Superfortress was the first large and heavy aircraft specifically used for photographic reconnaissance and mapping during World War II. In this role, modified B-29s and B-29As were designated F-13 and F-13A, respectively, reflecting their focus on reconnaissance photography. This designation arose from the USAAF’s system of using “F” as a prefix for reconnaissance-photographic aircraft.
As the United States began striking the Japanese home islands in 1944, the need for a long-range reconnaissance aircraft became critical. The B-29, known for its long-range capabilities, was a natural choice for these missions. Consequently, many Wichita-built B-29s and Renton-built B-29As were modified for reconnaissance at Boeing’s modification center in Denver, Colorado.
The Wichita-built B-29s, designated as B-29-BW, were powered by Wright R-3350-23 engines, while the Renton-built B-29A-F-13 models used R-3350-57 engines. Both types could reach speeds exceeding 330 mph.
These reconnaissance variants were equipped with six cameras: three K-17Bs, one K-18, and two K-22s. The camera setup was mounted below and aft of the crew compartment, with a modified B-3 Driftmeter operated by the photo-navigator stationed in the bombardier’s compartment. A dedicated camera specialist was part of the crew to maintain and operate the equipment during flight.
In June 1948, the remaining F-13s and F-13As were redesignated as RB-29 and RB-29A, respectively, during a broader reclassification of USAF aircraft types. The “RB” prefix indicated their role as Reconnaissance Bombers, reflecting the new nomenclature where “F” stood for Fighter instead of Pursuit.