Northrop YRB - 49A
The Northrop Corp. proposed a modification to the YB-49 Flying Wing bomber, called the YRB-49A. One YB-35A was modified with six jet engines and became the YRB-49A. Although its small radar signature had been noticed during tests during the late 1940s, it was the YB-49‘s high altitude and long-range flying abilities that gave it consideration as a spy plane. The plane promised a 400-mph cruise speed at 35,000 feet. The YRB-49A carried two of its six jet engines in pods below the wing, making room for more fuel. The aircraft was designed for the photo reconnaissance role and had camera equipment installed in the center and aft fuselage. The YRB-49A made its first flight on May 4, 1950. A brief test program of only thirteen flights was conducted before the aircraft was put into storage in late 1950. The YRB-49A sat until it was scrapped in late 1953.
Northrop YB - 49
The Northrop YB-49 was the jet-propelled variant of the XB-35 bomber. Two XB-35‘s were retrofitted with eight Allison J-35-A-15 jet engines and dubbed YB-49‘s. The first flight of the YB-49 occurred during October 1947. Four vertical fins were added, protruding both above and below the wing. Finally, the leading edge of the wing was modified in order to accommodate the air intakes for the engines. During the YB-49‘s flight test, it was discovered that the bomber handled more like a fighter, out turning its P-80 chase plane on several occasions. It was said that the air traffic controllers even had a difficult time locating the bomber on radar. On 5 June 1948 the second YB-49 crashed while performing speed runs at altitude. Flight testing revealed stability problems which could not be corrected with existing technology. The bomb bays were too small for the nuclear weapons of the day. The program was canceled by the Air Force in 1949. The YB-49 was simply a generation ahead of its time.
Northrop XB - 35
The XB-35 was America‘s first attempt at an all-wing heavy bomber. In the darkest days of World War II, when it appeared that Nazi Germany might well conquer Great Britain and the Soviet Union, the Army Air Forces saw the need for a large bomber with intercontinental range. Such a plane, based in the United States, must be able to cross the Atlantic and hit Germany with a large bomb load. The XB-35 was required to carry a 10,000-pound bomb load a distance of 10,000 miles. Four Pratt & Whitney R-4360 engines mounted internally, close to the leading edge. Each engine drove a pair of counter-rotating four-bladed propellers by means of a long extension shaft and a complex gearbox. The XB-35‘s first flight, on June 25, 1946, was a success. But that was about the only trouble-free flight the bomber was ever to have. Numerous equipment failures had already delayed the plane‘s development by more than a year. Only three B-35s were completed. The remainder of the initial test models were converted to jet power.
The Horten Vc was converted from the Ho 5b, which had been badly damaged by the elements. In Minden the two-seat Ho 5b became a single-seat aircraft. The pilot was accommodated in a normal seated position. The Ho 5a‘s Hirth engines were retained, as were its steel tube and wood construction and fixed undercarriage. As property of the military, it was finished in standard Luftwaffe camouflage. The Ho 5c made its first flight on May 26, 1942.Construction of the Ho 7 took place at the Goettingen Bureau. The aircraft‘s wings, were of wooden construction, while the center section was of welded tube steel construction with Dural skinning. The aircraft made its first flight in May 1943.
Armstrong Whitworth AW.52
Through being involved in laminar-flow wing development Armstrong Whitworth was keen to put its experience to practical application and proposed a jet-powered four-engined 120ft span laminar flow flying wing bomber. The design was to be evaluated through the use of a 1/3 scale glider. The end of the war brought an end to the project but not before work had started on the AW-52G glider. It first flew on 2 March 1945. Armstrong Whitworth, after cancellation of the bomber project, maintained its interest in a large flying wing and was eventually given a contract to produce two prototypes. To give some point to the project beyond research the type was designed to carry 4,000lbs of mail. The first Nene-powered aircraft flew on 13 November 1947 and eventually achieved speeds of around 500mph. It crashed on 30 May 1949 through control problems and the pilot, John Lancaster, made the first emergency ejection in Britain. The 2nd AW52 was powered by the Derwent and it flew on 1 September 1948, later on trials with the RAE until May 1954 when it was scrapped.
Northrop XP - 79B
Northrop chose to construct the aircraft out of a non-critical war material, magnesium. The XP-79 was to be powered by an Aerojet XCAL-2000 rocket motor capable of propelling the aircraft to 40,000 feet at 538 mph. The XP-79 was to have landing skids. However, it was later decided to incorporate retractable quadracycle landing gear. The aircraft would have a wingspan of 38 feet and a length of 13.22 feet. During March 1943, the decision was made to modify the third XP-79 to be powered by two Westinghouse 19-B axial flow jet engines in place of the Aerojet XCAL-2000 rocket motor. This aircraft would be known as the XP-79B. On 12 September 1945, the XP-79B, piloted by Harry Crosby, took off for the first time. Two Westinghouse 19-B (J-30) engines powered the aircraft. After about fifteen minutes of flight, the XP-79B entered what appeared to be a normal slow roll from which it did not recover and the pilot was killed. With the destruction of the sole XP-79B, the program was canceled.
Chance Vought V - 173
One of the most unusual aircraft ever designed for the U.S. Navy was the Chance Vought V-173, also known as the Zimmerman „Flying Pancake“. It was a prototype „proof of concept“ aircraft that lacked wings, instead relying on its flat circular body to provide the lifting surface. This multi-million dollar project nearly became the first V/STOL (vertical takeoff and landing) fighter. The V-173 blueprints were shown to the Navy in 1939, with wind tunnel tests on full scale models being done in 1940-41. Flight testing of the V-173 went on through 1942 and 1943, resulting in reports of „flying saucers“ from surprised Connecticut locals. The V-173 prototype was saved and was given to the Smithsonian.
Chance Vought XF5U - 1
The letter of intent for the Vought VS-315 (XF5U-1) was issued September 17, 1942. The XF5U-1 was a twin-engine, single-seat, low aspect ratio flying wing type of airplane. The first XF5U-1 airplane was used for static tests. The second XF5U-1 airplane was used for experimental flight test and concept validation. It was never flown because many hours of engine run-up showed excessive mechanical vibration between the engine-propeller shafting, gear boxes, and airframe structure. The airplane was taxi tested in February 1947 at Stratford, Connecticut, but, again, vibration levels were considered excessive. The airplane was being readied for shipment by sea through the Panama Canal to Edwards AFB, California, when the contract was canceled.