The B-57 is one of only two major combat aircraft of foreign design adopted for use by the United States military since the end of World War II. The first of the bomber variants went into service in 1954. In 1955, a major redesign of the Canberra was begun to develop a high-altitude reconnaissance version. This version called the RB-57D proved to be of limited use due to problems with the new long wing which eventually led to the grounding of the aircraft. General Dynamics designed an even larger wing that solved the problem. The RB-57Fs were rebuilt from earlier aircraft and given new serial numbers along with their new wings.
National Aeronautics and Space Administration, 1975
Pima Air & Space Museum