General Dynamics RB-57F Canberra take off (S/N 63-13291) Originally this aircraft was a B-57B, S/N 52-1574. Note the main landing gear is almost fully retracted. The ailerons were positioned at mid-span and supplemented by spoiler on the upper outer wings. (U.S. Air Force photo)
General Dynamics RB-57F Canberra 3/4 front view (S/N 63-13296) Originally, this aircraft was a B-57B, S/N 53-3918, of the 58th Weather Reconnaissance Squadron. Photo taken at Webb AFB, Texas on May 8, 1965. (U.S. Air Force photo)
The RB-57F was the result of an Air Force request for a high-altitude reconnaissance aircraft with better performance than the RB-57D. Because General Dynamics was responsible for contract maintenance on the D model, the USAF asked for a conversion proposal for the new aircraft, which was to become the RB-57F. A prototype conversion contract was awarded in the fall of 1962 and the first aircraft made its first flight on June 23, 1963.
The RB-57F design incorporated many major changes. The first was the greatly enlarged wing. The wing had a span of more than 122 feet, which was 14 feet more than the RB-57D and nearly double that of a B-57B. The second obvious change was the replacement of the Wright J65 turbojets with Pratt & Whitney TF33 turbofan engines. The TF33s gave the aircraft more than double the thrust of the B model. The RB-57F was also capable of being fitted with two Pratt & Whitney J60 turbojets, which were mounted in pods and could be attached to the wings outboard of the TF33s. These auxiliary engines were only for use at altitude, in fact, they were not equipped with starters and had to be air started while the aircraft was in flight. At altitudes above 40,000 feet, the J60s generated about 3,300 pounds of thrust each and increased the maximum altitude of the RB-57F by 2,000 to 3,000 feet. The size of the tail was also greatly increased. The height of the vertical stabilizer was increased to 19 feet and, combined with an increase in the width, doubled the area of the stabilizer, which was necessary for yaw control at very high altitudes (up to 80,000 feet). The electronics were also updated on the F model. The nose of the aircraft was lengthened to house sophisticated navigational equipment along with sensitive detection devices for gathering electronic/signal intelligence. The wings had four hard points various camera and air sampling pods could be mounted when the J60 engine pods were removed.
A total of 21 aircraft were modified by General Dynamics to the RB-57F configuration: three RB-57As, 14 B-57Bs and four RB-57Ds. Because of the extensive changes incorporated into the F model, the aircraft were given new 1963 serial numbers as they were completed. Most of the F models operated by the USAF were assigned as weather reconnaissance aircraft and used in part to measure radiation levels after above ground nuclear weapons tests conducted by other countries.
Big wing, new engines
TECHNICAL NOTES: Armament: None (although the bomb bay could be converted to carry bombs if necessary) Engines: Two Pratt & Whitney TF33-P-11 turbofans of 16,000 lbs. static thrust each, plus two (removable) Pratt & Whitney J60-P-9 turbojets of 3,300 lbs. static thrust each Maximum speed: 550 mph / 475 knots Range: 4,000 miles / 3475 nautical miles Service ceiling: 82,000 ft. Span: 122 ft. 5 in. Length: 68 ft. 10 in. Height: 19 ft. 0 in. Crew: Two (pilot and navigator-observer) Serial numbers: 63-13286 to 63-13302; 63-13500 to 63-13503