The other Superfortress....

Boeing B-50:  The Second Superfortress

By

Scott Schwartz

     Believe it or not, two Boeing airplanes carried the famed Superfortress name.  Most of us are familiar with the B-29, which saw extensive use against Japanese cities during World War Two, as well as service during the Korean War.

     Less well-known, however, is the Boeing B-50.  One reason for this might be that the B-50 looks almost exactly like the B-29.  The external differences between the two are subtle. 

     Here are two ways to tell the planes apart.  First, look at the vertical stabilizer.  The B-50’s vertical tail is 6ft taller than that of the B-29.  Stare at the B-50’s tail long enough, and you will see that the vertical fin looks bigger than the one found on a “regular” B-29.  Next, look at the engine nacelles.  You will note that the “chin” scoop (for the oil coolers) on each engine is located below and toward the rear of each engine.  Whereas the B-29’s engine nacelles present a flat appearance when viewed head-on, the B-50’s engines seem to stick straight out from the leading edges of the wings.  This is because the B-50 was powered by four Pratt & Whitney R-4360, 28 cylinder engines. On the other hand, the B-29 had four Wright R-3350 18 cylinder, two row engines.  On the B-50, each engine consisted of four rows of 7 cylinders.  Because they were longer, the B-50’s engines protrude further from the wings.  

     Now that we can tell the difference between the two, let’s talk about why the B-50 even exists.  The B-50 actually began life as the B-29D.  The B-29D, itself, was an outgrowth of an experimental airplane – the XB-44, which was a B-29A that had been fitted with the R-4360 engines for test purposes. The experiment led to an order for two hundred of the airplanes, which were designated as B-29D’s.  This was in 1945.  When the war ended, the order was cut back severely.  There seemed to be no point in buying an airplane which appeared to be an improved version of an older model that was already considered obsolete. 

     The Air Force, concerned about the problems with the B-36 strategic bomber program, needed an aircraft that was capable of carrying the atomic bomb – at least until the B-36 was past its teething troubles. 

     In a clever move, Air Force leaders argued that the numerous modifications incorporated into the B-29D, in fact, made it an entirely new airplane!  Accordingly, the B-29D was re-designated as the B-50 Superfortress, thus allowing the plane to slip past the bean counters and into production.  The B-50 made its first flight in 1947.

     The Air Force may have stretched the truth, but only slightly.  The B-50 shared only a 25 percent parts commonality with the B-29.  The majority of the changes were internal. The wings and fuselage, although similar in appearance to those of the B-29, were constructed differently and used a stronger type of aluminum.   Other changes included a steer able nose wheel, larger flaps, an improved wing de-icer system, and a faster landing – gear retraction system. 

     Its 28 cylinder engines gave the B-50 a top-speed of just under 400mph, and a service ceiling of 37,000 feet.  A crew of 11 manned the airplane and it should be noted that the gun system was basically the same remotely controlled system as the one found in the B-29.

     A few B-50’s were modified to be able to receive in flight refueling.  One of these, “Lucky Lady II”, made the first flight around the world and was able to remain airborne for 94 hours in order to complete the trip.  This flight took place in 1949.  Ironically, this B-50 was refueled en route by KB-29 tankers!

     370 B-50’s were built, and they served the now-defunct Strategic Air Command until 1954.  By then, the Boeing B-47 Stratojet and Convair B-36 were in service. The B-52 entered service during the following year. 

     After it was supplanted as a strategic bomber by other types, the B-50 continued to serve in a variety of roles.  Eleven were converted into TB-50 navigation trainers.  Some became KB-50 tankers, and 37 became WB-50 weather reconnaissance aircraft.  The last WB-50 in operational service was ferried to the Air Force Museum in 1968!  The KB-50 and WB-50 models were also equipped with two General Electric J-47 auxiliary turbojet engines.  The jet engines were hung in pods under each wing.

     Although the WB-50 flew well into the late 1960’s, another B-29 cousin, the KC-97 tanker saw service with Air National units until 1979.  Although the KC-97 used the same wings, engines, and empennage as the B-50, the C-97 prototype was originally fitted with B-29 wings and engines. 

 

     Cynics may sneer at the “white lie” told by the Air Force in order to procure the B-50.  But the B-50 was conceived during a time when the threat of global nuclear war loomed large.  Thankfully, the airplane’s effectiveness as a nuclear bomber was never put to the test.

     

Boeing B-50 Superfortress at the Castle Air Museum in Merced, CA.
Photo by Scott Schwartz