The flying boom prototype and the specially modified receiver - B-29A-65-BN, serial 44-62205 - first flew together on October 3, 1948. Air Materiel Command test crews made the first ‘dry’ hook-up eight days later. On that occasion, they remained ‘in contact’ for approximately 20 minutes. The first ‘wet boom’ test between a B-29 tanker and a B-29 receiver was made in August 1949.

Air refuelling tests with the RB-45C were conducted over Southern California in July 1950. RB-45Cs flown by RAF crews and carrying British markings were also air refuelled by KB-29Ps of the 91st AREFS during covert operations over the Soviet Union in the spring of 1952.

The boom and ‘boomer’ station of a KB-29P (ex Wichita-built B-29-65-BW) of the 97th AREFS at Biggs AFB, Texas, on July 6, 1951, ten months after this squadron became the first to be equipped with boom tankers.

The feasibility of modifying the F-86A for boom refuelling was demonstrated during tests in July 1950. However, 49-1172 was the only Sabre so modified. The receptacle position forward of the cockpit necessitated removal of the armament. Not quite a practical solution for a fighter...

The F-84G version of the Thunderjet was specially fitted with an air refuelling receptacle in the leading edge of the left wing to meet SAC’s need for jet fighters capable of escorting its bombers. Here, the KB-29P is a Martin-built B-29-55-MO with a F-84G-1-RE.

Serial 42-93921, the aircraft modified as the prototype for the flying boom installation, had been built in Boeing’s Renton plant as a B-29A-10-BN. It went into the modification shop at Plant II in Wichita, Kansas, on May 27, 1948. The row of five triangle-shaped fairings protruding beneath the centre fuselage are the aft-facing lights to assist the receiver pilot in maintaining the proper vertical separation behind and below the tanker.

During air refuelling, the forward dorsal turret of B-50Ds had to be turned sideways to prevent the boom from getting tangled up with the four 0.50-in guns. The KB-29P/B-50D team worked together until the last B-50D, aircraft 49-330, was phased out of the SAC force on October 20, 1955.

Two-view drawing of the Boeing KB-29P boom.