A couple of operated during the Vietnam War on missions reminiscent of relaying ELINT knowledge, however have been changed by more environment friendly and capable Boeing RC-135s. B-47 and aircrews. These were "simulated strike missions against the then Soviet enemy". To shorten the landing roll, USAF test pilot Major Guy Townsend promoted the addition of a 32 ft (9.Eight m) German-invented "ribbon" drag chute (thrust reversers had not then been developed).

All were powered by J47-GE-11 turbojets, offering the same 5,200 lbf (23 kN) thrust as the earlier J47-GE-3, and had built-in rocket-assisted-take-off (RATO) bottles. The primary prototypes had been fitted with General Electric J35 turbojets, the manufacturing version of the TG-180, with 3,970 lbf (17.7 kN) of thrust. Flight testing of the prototypes was cautious and methodical since the design was new in so many ways. Both XB-forty seven prototypes were test flown at Edwards AFB; the first XB-forty seven (46-065) was disassembled and scrapped in 1954, making the second prototype (46-066) the only surviving XB-47.

The XB-47 prototype flew its first flight on 17 December 1947 (the anniversary of the Wright Brothers' first 4 flights on 17 December 1903), Vape Kits with take a look at pilots Robert Robbins and Scott Osler on the controls. The second XB-forty seven (46-066) prototype first flew on 21 July 1948 and, following its delivery to the USAF in December of that year, served as a flying take a look at bed till 1954. Its final destination was Chanute AFB the place it was used as a maintenance and familiarization aircraft.

The ultimate 15 RB-47s, built from December 1955, were fitted with further tools, together with the AN/APD "facet wanting airborne radar" (SLAR) system, and gear to sample the air for fallout from nuclear checks. The USAAF awarded examine contracts to all 4 corporations, requiring that North American and Vape Tanks Convair focus on four-engined designs (to turn out to be B-forty five and Vape juice XB-46), while Boeing and Martin have been to build six-engined aircraft (the B-47 and XB-48). They have been upgraded to B-47E standard in 1956 under the Ebb Tide program, joined by forty one extra early construct aircraft, also designated TB-47B.

During 1963, final phaseout of B-forty seven bomber wings began; the last have been out of SAC service by 1966. The final USAF operational aircraft, WB-47Es assigned to the Air Weather Service, had been withdrawn from use in September 1969. Shortly earlier than, a B-47E, USAF Serial Number 53-2280, was used as a testbed for Vape Store a newly developed fly-by-wire system. Because the training for this imposes repeated excessive stress on the aircraft, Vape Clearance the airframe lifetime would have been severely limited by steel fatigue, and Vape Clearance this maneuver was eradicated.

Stress and fatigue incurred in low-altitude operations led to various wing failures and crashes, and an extensive refit program was begun in 1958 to strengthen the wing mountings.