The RB-50G and Project Half Track


Boeing RB-50G Superfortress
343rd Strategic Reconnaissance Squadron, Yokota Airbase, Japan, July 1953

This rendering is dedicated to the memory of Capt. John Roche, USAF who passed recently.
Captain Roche was the only survivor of the shootdown of this aircraft on the day after the Korean War armistice was signed. The aircraft was operating in international airspace near Vladivostok in the Soviet far east when it was attacked and shot down by MiG-15s. The entire crew, save for Capt. Roche (the copilot) died in the crash, or were drowned afterward.
Capt. Roche survived, and carried on the memories of his fallen crew-members in strict secrecy until the events surrounding the shootdown were declassified in the 1990s.

Electronic reconnaissance was the primary mission of the RB-50G which entered SAC service between June and October 1951. Fifteen RB-50G conversions were made and differed significantly enough from the RB-50E and F that they were assigned the Boeing Model 345-30-025 number. The RB-50G featured six electronic countermeasures stations internally, with external modifications to accommodate the radomes and antennae of the aircraft’s new radar equipment. During the reconfiguration process, RB-50G was fitted with the improved nose of the B-50D, which had a large moulded plastic cone and an optically-flat bomb-aiming window in the lower portion. In contrast to the RB-50F, the RG-50G could use its defensive armament while operating its new electronic equipment.

The normal crew complement was sixteen: pilot, copilot, navigator, engineer, nose gunner, top gunner, left side gunner, right side gunner/radio operator, radar operator, tail gunner, plus six electronic countermeasures operators. Ten cameras could be carried – four K-38s with 36-inch lens, or two K-38s with 24-inch lens; one L-22A or K-17; one A-6 motion picture camera; three K-17cs; one T-11 with 6-inch lens.

The 7499th Group was engaged in supporting the new Matador and Mace tactical guided missiles in Europe. The 7405th and 7406th Squadrons each flew a special kind of airborne collection mission – not traditional photo collection, and it certainly wasn’t signals intelligence. It was imagery of a special sort, designed to support a tactical missile guidance system called the Automatic Terrain Recognition and Navigation (ATRAN) system, and the time frame was 1955-56.

In the early 1950s, the Air Force had fielded two versions of the Matador which depended upon positive guidance control by radar-directed ground controllers. The maximum range was about 200 miles, and they would be very susceptible to enemy countermeasures. So ATRAN was to be employed in the TM-61B version to correct those problems. The TM-61B was to evolve into the TM-76A Mace missile with a much-improved performance; this ATRAN-equipped Mace version was to stay in the Air Force inventory in Europe until September 1966.

The difficulty was how to get the required ground imagery to create the matching film. The main area of employment of these missiles was to be Western Europe, so collection would be in that arena. The hope was that reconnaissance missions and other intelligence sources would provide enough accurate data to be created and uploaded into the missiles. Headquarters US Air Forces in Europe (USAFE) at Wiesbaden, Germany, activated the Support Group at Wiesbaden in mid-1955. The 7499th Group would run its ATRAN missions under the project name ‘Project Dream Boat’. Two squadrons would have the ATRAN task among others. The 7405th Support Squadron would collect ATRAN material using a Douglas C-54D under Project ‘Lulu Belle’ – the 7406th Support Squadron would use three Boeing RB-50Ds and a RB-50G under Project ‘Half Track’.

Each of these aircraft would use specialised radar scope imagery, coupled with simultaneous regular photography, to get the required information. Each was limited to flying its missions over friendly territory, but this would enable the best possible accuracy for that part of a missile’s flight path from launch until crossing into hostile territory.

The C-54 would be a very logical choice for ATRAN missions covering terrain underneath and near the air corridors to Berlin. Aircraft flying in the corridors were usually required to land at Tempelhof and would be subject to Soviet observation and probable complaints if they were perceived to be other than transport aircraft. Thus the RB-50s were disqualified on this ground as well being too large for the Tempelhof runways. Available photographs of the project C-54 show few protuberances to draw suspicion to it. The RB-50 might have been the best available choice for the missions over Western Europe because it could carry a heavier load of special equipment.

The RB-50D aircraft to be used in the Project Half Track part of ATRAN would seem an unlikely choice for low level intelligence gathering missions. Flying the huge modified bombers out of Rhein Main Air Base in Frankfurt, Germany, were crews of the 7406th Support Squadron which was activated in May 1955 and was to have two missions, both with RB-50s. One would be communications intelligence collection, with the RB-50G version, and the other was to be ATRAN route collection, with three RB-50Ds. The ATRAN aircraft were modified by Goodyear at Akron, Ohio, before being assigned to the 7406th. Problems at Goodyear delayed the arrival of the three aircraft (serial numbers 48-107, 49-307, and 49-312) until spring 1956. Finally all three were available, and the first ATRAN mission was flown 1 June 1956.

The 7406th Support Squadron memoirs describe the missions: “The Half Track RB-50D aircraft had two pilots, two navigators, a flight engineer, a radio operator, two scanners/gunners, and a tail gunner… The “Half-Track” back-end crew consisted of two persons that were not members of the 7406th. These two sat in the scanner/gunner compartment, aft of the bomb bays, during take off and landings. During missions these two sat on a platform in the forward bomb bay…Low level flights commencing from points in Western Germany were flown to the East German border’. They would fly as ‘…straight a line as possible from middle Germany to the East/West German border at 500ft and 1000ft absolute altitude, and pull up at the border. At times an aircraft would return to Rhein/Main with tree limbs wrapped around the aircraft tail skid’.

The 7406th flew about seven Half Track missions per week at first. Between July and September 1956, 52 more missions were flown. But then came the word that on 19 October 1956 the squadron was to be relieved of the Half Track ATRAN mission. Like the Lulu Belle C-54, the Half Track RB-50s were judged not able to produce the quality information needed. ‘The equipment on the aircraft was not able to do the mission within specified tolerances. The same job would be done by synthetic methods.’




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