On July 5, 1942, Northrop demonstrated a gigantic full-size mock-up of a future strategic bomber in a "flying wing" design to representatives of the US Air Force. The wingspan of 52.43 m with a sweep of 27 degrees made an indelible impression on the commission. Due to the low drag of the wing, the future bomber was supposed to develop high speed, while in the wing it could carry a large supply of fuel and bombs.
On December 17, 1942, the US Air Force ordered 13 strategic bombers called YB-35 to Northrop for military trials.
The order from the Air Force arrived on June 30, 1943. According to the terms of the contract, Northrop was to deliver the first production bomber to the Air Force by June 1945, but the company was forced to postpone the construction date of the first production aircraft all the time, finally marking it as 1947.
The aircraft were made from a new high-strength aluminum alloy developed by Alcoa.
The power plant consisted of the most powerful air-cooled piston engines of that time and two Pratt and Whitney R4360 turbochargers. Such an engine developed a power of 3000 hp. at an altitude of 10,500 m. The motor was not yet mass-produced, but the company provided prototypes for new developments. Twenty-eight cylinders of the engine rotated a crankshaft connected through a cardan joint and a hydraulic clutch to a gearbox for driving two coaxial three-blade propellers. The first screw had a diameter of 4648 mm, the second - 4597 mm. The propellers were carried out on long shafts far back, beyond the trailing edge of the wing, the propeller axes were located at an angle of 8 ° to the horizontal.
On June 25, 1946, the XB-35 with w/n 213603 took off from the factory airfield at Hawthorn and made a successful 45 minute flight.
The second prototype XB-35 made its maiden flight on June 26, 1947.
In September 1947, first three-bladed and then four-bladed propellers of variable pitch of the Hamilton Standard type were installed on the first XB-35. On February 12, 1948, the bomber made its maiden flight with new propellers.
At the end of 1948, due to the complete futility of work on piston bombers, the Air Force made the final decision on the B-35. Nine unfinished YB-35s were converted into scouts. Instead of four piston engines, it was planned to install six J33 turbojet engines on them, two engines were suspended on pylons under the wing, and four were placed inside the wing. Modifications were assigned the designation RB-35B.
In August 1949, funding for the work of the Northrop company was reduced, and the RB-35B program was reduced to the construction of one aircraft.
Ironically, the modern American bomber "Northrop B-2 Spirit", which embodied the technical solutions of John Northrop, was put into production eight years after his death.
|Wing span, m
|Wing area, m²
|2 × PE Pratt & Whitney R-4360-17
+ 2 × PE R-4360-21 Wasp Major, hp
|2 × 3000
+ 2 × 3000
|Weights and loads, kg:|
|Maximum speed, km/h
|Cruising speed, km/h
|Service ceiling, m
|Ferry range, km
|Combat range, km
Armament. Three turrets with four and 4 turrets with two 12.7 mm machine guns (1000 rounds for each). The bomb load is 23245 kg maximum and 18700 kg is normal. The bomb load was evenly distributed over the wing and was placed in eight bomb compartments - four compartments on each half wing.