Six turning and four burning

Sunday, October 15th, 2017

The Convair B-36 Peacemaker was the largest mass-produced piston-engined aircraft ever built, with the longest wingspan of any combat aircraft ever built:

The genesis of the B-36 can be traced to early 1941, prior to the entry of the United States into World War II. At the time it appeared there was a very real chance that Britain might fall to the German “Blitz”, making a strategic bombing effort by the United States Army Air Corps (USAAC) against Germany impossible with the aircraft of the time.


After the establishment of an independent United States Air Force in 1947, the beginning in earnest of the Cold War with the 1948 Berlin Airlift, and the 1949 atmospheric test of the first Soviet atomic bomb, American military planners sought bombers capable of delivering the very large and heavy first-generation atomic bombs.

The B-36 was the only American aircraft with the range and payload to carry such bombs from airfields on American soil to targets in the USSR. The modification to allow the use of larger atomic weapons on the B-36 was called the “Grand Slam Installation”.


Beginning with the B-36D, Convair added a pair of General Electric J47-19 jet engines suspended near the end of each wing; these were also retrofitted to all extant B-36Bs. Consequently, the B-36 was configured to have ten engines, six radial propeller engines and four jet engines, leading to the B-36 slogan of “six turning and four burning”. The B-36 had more engines than any other mass-produced aircraft. The jet pods greatly improved takeoff performance and dash speed over the target. In normal cruising flight, the jet engines were shut down to conserve fuel. When the jet engines were shut down, louvers closed off the front of the pods to reduce drag and to prevent ingestion of sand and dirt.

The B-36 features prominently in the 1955 film Strategic Air Command, along with Jimmy Stewart, who was a real-life military pilot:


  1. It’s interesting, a lot of sources talk about how the B-36 was rendered obsolete by the advent of first jet fighters but that wasn’t actually the case (at least not at first). It flew at an altitude where even F-86/MiG-15 era fighters were barely controllable (in tests, the force of firing the F-86′s guns at that altitude alone was enough to cause dangerous flight instabilities). Because of it’s large control and flight surfaces, the B-36 could actually out-maneuver jet-fighters sent to intercept it at its cruising altitude. It took another several years of jet development before it became truly vulnerable, by which point it was being phased out.

    Occasionally, SAMs are mentioned as a cause of obsoletion, but only by the standards of the rosy projections of missile performance common to the ’50s. The early SAMs were atrociously unreliable in service.

  2. Lu An Li says:

    So many B-29s [previously unopposed] over Korea were shot down by MiG-15s that the bomber raids had to be stopped. Even with escorts. Losses prohibitive.

  3. Bruce says:

    Jerry Pournelle wrote somewhere that B-36s normally landed in the ditch next to the runway. Largest wingspan ever isn’t great when you try to land.

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