In February 2016 the U.S. Air Force announced that the new LRSB (Long-Range Strike Bomber) project had an official designation; B-21. A picture was released which shows, as the new designation implies, an aircraft that is very similar to the B-2. The first of these new aircraft won’t enter service until the mid-2020s. The B-21 is yet another effort to replace the 1950s era B-52 and the air force is determined to learn from the problems encountered with the last (B-2) effort, which cost so much the eventual number built shrank from 132 to 21. The USAF insists that each B-21 will cost about $600 million and the entire program $80 billion. About 30 percent of program cost will be for development and the rest for building about a hundred aircraft.
The B-21 plan was designed to avoid past problems, especially the endless lawsuits from companies that lost design competitions as well as unpredictable and always escalating costs. Two companies were in competition to be the prime (chief) contractor for the project and the loser, Boeing, has agreed to no more legal challenges to the winning bid from Northrup. The air force and major suppliers agree on the importance of getting the B-21 into service on time and under budget.
The B-21 is the latest reboot of air force efforts to create a new heavy bomber. Since the 1990s the air force has been working on the next heavy bomber diligently but without much success. In 2003 the air force announced a development plan that would enable it to start testing a new heavy bomber using very advanced technology by 2037. That did not work out and in 2009 the Department of Defense told the air force that there was be no more money for developing a new heavy bomber. Not for a while, anyway.
Models of what the 2003 bomber might look like were released and the "B-3" (officially the NGB, or New Generation Bomber) looked like the B-2. From the beginning there were only two firms willing and able to compete for the new bomber contract; Northrop Grumman and Boeing. Proposals from both firms were for a B-3 that looked like the B-2. For the Northrop Grumman proposal, the main difference was that the stubby wings are "cranked" (moved forward a bit, rather than continuing in a straight line from the body of the aircraft).
These derivative designs are apparently still favored because the air force knows it was unlikely to get the money for a radical (and expensive) new design. Until recently they were told they would have a difficult time getting money for a "B-2 Lite." There was also talk of building a B-3 that could operate with, or without, a crew. The air force rejected UAV angle. The air force spent several billion dollars on B-3 development. All was not lost. The B-3 spec called for a smaller and stealthier aircraft that carried a ten ton bomb load (less than half what current heavy bombers haul). This recognized the efficiency of smart bombs, which are more than a hundred times more effective than unguided bombs. The B-2 is a 170 ton aircraft and 43 percent of that is fuel. The B-2 alone weighs 71 tons and maximum weapons load is about 23 tons. The seeming success of the B-3 development work and the stark reality that the B-52s and B-1Bs would eventually wear out got the air force enough support to go forward with the B-21, which will replace the 138 B-52s and B-1Bs.
The air force has always believed the political and budget problems could slow down the two decade long air force effort to get a new heavy bomber, but won't stop it. Since the late 1990s the air force has been working on a replacement for its elderly but still very useful B-52s. There are two other heavy bombers in service (B-2s and B-1B) and these two both failed to replace the B-52.
The air force is acutely aware of the fact that their first heavy bomber, the B-17 "Flying Fortress," entered production in 1937 and that the current problems getting a new heavy bomber program going means there has been a record long period in which there was no heavy bomber in production or development. In contrast during the sixty year period from the early 1930s to the early 1990s there were fifteen heavy bombers developed. Thirteen of them actually entered service; B-17 in 1939, B-24 in 1942, B-29 in 1944, B-32 in 1945, B-50 in 1947, B-45 in 1948, B-36 in 1948. The B-49 "Flying Wing" cancelled in 1952 but the B-47 entered service in 1952, the B-52 in 1955, B-58 in 1960 and FB-111 in 1969. B-70 development was halted in 1966 but the B-1 arrived in 1985 and the B-2 in 1992. But since 1992 nothing has come of air force efforts to design and develop a new heavy bomber.
This is all about trying to improve on the B-52, Since the 1950s the air force has developed six heavy bombers; the 240 ton B-52 in 1955, the 74 ton B-58 in 1960, the 47 ton FB-111 in 1969, the 260 ton B-70 in the 1960s, the 236 ton B-1 in 1985, and the 181 ton B-2 in 1992.) All of these were developed primarily to deliver nuclear weapons (bombs or missiles), but have proved more useful dropping non-nuclear bombs. Only the B-70 was cancelled before being deployed. The B-1 was delayed and almost cancelled, but proved that the air force would do anything to keep the heavy bombers coming.
Meanwhile, the most cost-effective bombers continue to be the half century old B-52s, simply because they are cheaper to operate. The well maintained B-52s are quite sturdy and have, on average, only 18,000 flying hours on them. The air force estimates that the B-52s won't become un-maintainable until they reach 28,000 flight hours. Thus these aircraft could serve into the 2030s. The B-1 and B-2 were meant to provide a high tech (and much more expensive) replacement for the B-52, but the end of the Cold War made that impractical. The kinds of anti-aircraft threats the B-1 and B-2 were designed to deal with never materialized. This left the B-52 as the most cost effective way to deliver bombs. The B-1s and B-2s are getting some of the same weapons carrying and communications upgrades as the B-52, if only because these more modern aircraft provide a more expensive backup for the B-52.
Since 200 more people belied it was increasingly likely that the next heavy bomber would be smaller (perhaps only 60-100 tons) subsonic, stealthy, possibly uninhabited and familiar looking. The air force learned the hard way (the B-2) that they will have to propose a substantially cheaper aircraft as well, if they ever want to get Department of Defense backing for a new heavy bomber. The B-21 will have to be cheaper and delivered on time. There has not been a lot of that in the air force for many years. It will be interesting to see how this plays out.