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USAF designation: YRB-49A, RB-49A-CF (cancelled) Engines: 6 x 5,600 lb. Alison J35-A-19 (or -15?) First flight: May 4, 1950 (by Fred C. Bretcher, Dale Johnson) Like the canceled B-49, the RB-49A grew out of the unconventional XB-35, under development by Northrop since 1941. In April 1948, the Air Staff and high ranking officers of the Air Materiel Command, after comparing reconnaissance versions of the Northrop B-35, Boeing B-47 and B-50, and Republic F-12, concluded that perhaps the eventual RB-49A could "realistically" perform a portion of the strategic reconnaissance mission. Undoubtedly, this optimistic appraisal stemmed from the testing already accomplished on the Northrop aircraft, as well as from the aircraft's range, speed, altitude, and growth potential with combinations of turbojet and turboprop engines. Therefore, 3 versions of an ever improving RB-49A were planned — an initial aircraft with eight TB-190A (General Electric J47) turbojets, an interim model powered by six Westinghouse J40 engines (when they became available), and an ultimate configuration, which would achieve greater range and economy with two Turbodyne T37 turboprops and two TG-190A engines. The ultimate model was not an immediate possibility, since the T37 engines would not be available until October 1951 or later. However, the aircraft's basic development did not take shape until March 1948 when the contractor, after canvassing possible uses for the "flying wing;' submitted to the Air Force proposals for a photographic reconnaissance version of the aircraft. Briefly referred to as the FB-49A, then the RB-49A, the proposed aircraft would be essentially a YB-49, stripped of items required only for bombardment missions and incorporating necessary photographic apparatus. The formal nomenclature of the prototype became YRB-49A, a six-engined reconnaissance bomber with two engines in underwing nacelles to increase the volume available for fuel, which was the last chance for the flying wing design. It was initially planned for five YB-35s and 4 YB-35As to be converted to six-jet configuration, fitted with cameras and redesignated RB-35B (later to be redesignated YRB-49A). Believing that the planned RB-49A configuration truly had merits, and still eager to salvage its costly investment in the unfortunate XB-35 program, the Air Force promptly decided to endorse the YRB-49A development. Following notice of the decision in May 1948, Northrop received a letter contract on 12 June for preliminary engineering work looking toward an eventual production contract for 30 reconnaissance aircraft, at a cost of $86,800,420, this total to include aircraft, engineering data, and flight testing. Signed on 12 August 1948, Contract W33-038-ac-21721 covered the production of 30 RB-49As and a static test shell. One of the aircraft was to be built by Northrop, the remaining 29 by Consolidated Vultee, at the latter's government leased plant in Fort Worth, Texas. The agreement had been preceded by difficult negotiations, the two contractors being unwilling from the start to accept the Air Force's contention that the nation would benefit from a pooling of Northrop's engineering skill and Consolidated's experience in quantity production of large aircraft. Support of the RB-49A production program was short lived. Less than 2 months after the contract's signature, several Air Materiel Command officials concluded that the program's initial eight jet version would only be "satisfactory as an interim installation." In late September, the Air Force also began to encounter difficulties in pinning down the 2 contractors' future delivery dates for the 30 RB-49As. Just as disturbing was the continuing indecision over which prototype Northrop would use to develop the YRB-49A. At first, the remaining YB-49 was chosen. Then, various versions of the 13 YB-35s ordered in 1942 were reviewed, before settling on modification of the third B-35 prototype, a YB-35A featuring specific reconfiguration changes dictated early in 1945. Against this clouded background, a board representing numerous Air Staff offices met in November to review the requirements for reconnaissance aircraft. All 3 versions of the future RB-49As came under fire. The 8 jet RB-49A, it appeared, would not be available until January 1950 and would have an inadequate operating radius; the 6 jet model, planned for 1951, would be much slower than the B-47; finally, Northrop could not promise the ultimate turboprop turbojet version until 1953, at which time that particular RB-49A would be in competition with (and outclassed by) the B-52. The Air Staff Board, therefore, recommended elimination of the RB-49A. The RB-49A production program was irrevocably canceled in late December 1948, as the new USAF Board of Senior Officers" supported the Air Staff Board's recommendation, deciding also soon afterward to substitute the procurement of additional B-36s for the deleted RB-49As. The RB-49 offered no real advantages over the B-47 and the new B-52. Only one YB-35A (42-102376) was modified with six jet engines as a YRB-49A. The RB-49 cancellation thefore became official in mid-January 1949, even before the single YRB-49A flew, when the Air Materiel Command directed Northrop to stop work on all phases of the reconnaissance version except for completion and test of the one YRB-49A. Conversion of the third YB-35A was "shop completed" by February 1950, shortly after the Northrop project was totally cut back to the level of a low budget, state of the art research and development endeavor. The YRB-49A differed significantly from the third YB-35A by featuring 6 engines instead of 8. Four of the YRB-49's six J35s were internally mounted; 2 were outside of the airframe. The removal of 2 engines and the relocation of an additional 2, allowed the YRB-49A to carry much more fuel, a configuration change designed to extend the aircraft's range. Yet, despite the contractor's continuing attempts to revive its program, the April delivery deadline set by the Air Force was not met. The YRB-49A's first flight occurred on 4 May, a one month slippage due to the time consumed in installing additional instrumentation. Like the YB-49, the reconnaissance prototype's first flight was from Hawthorne to Edwards AFB, California. The YB-49 and YRB-49A programs continued into the late 1940s and early 1950s, but neither of these jet powered flying wing programs was successful. The YRB-49A's test program was quickly marred by a potentially fatal accident. On 10 August 1950, during its tenth test flight, the reconnaissance prototype was in a climb at approximately 35,000 feet, at a speed of about 225 miles per hour, when the canopy failed and blew off, tearing away the pilot's oxygen mask and injuring him slightly. Only because the alert flight engineer supplied emergency oxygen was the pilot able to land the aircraft without further incident. The test program was resumed after a replacement canopy was provided and various aircraft modifications were made. No test flights were recorded after 20 September 1950, even though the aircraft was probably still test flown on and off. In any case, on 6 May 1952, the Air Materiel Command indicated that there was "no future flying time scheduled" for the YRB-49A. And so the last of the "flying wings" was flown to Northrop's Ontario International Airport facility, and it most likely remained in storage for 18 months. The Air Force reclaimed and scrapped the aircraft in November 1953. Population: 1 former YB-35A modified [42-102376] Specs: Performance: Crew/passengers: 3
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Northrop N-52 Flying Wing
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