RB / WB-57F
56th WRS / 58th WRS
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 23 June 1963.
RB-57F design incorporated many major changes. The first was the greatly
enlarged wing. The wing had a span of more than 122 feet; 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 lbs. 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 ft.).
The electronics Systems 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: 3 RB-57As, 14 B-57Bs and 4 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 US Air Force was assigned as weather reconnaissance aircraft and used in part to measure radiation levels after above ground nuclear weapons tests conducted by other countries.|
|Thanks to Tom Barrett and Gerald Tremmel|
|AIR WEATHER RECONNAISSANCE ASSOCIATION|
|RB-57F PROJECTS / MISSIONS|