Aviation Ancestery - February 2012
The B-29 Superfortress, Part Two
By Scott Schwartz
B-29’s roll down the assembly line, soon to be winging their way to targets in the Far East. (Photo courtesy of the USAF)Fire aboard an aircraft is something that is dreaded by pilots and aircrew. Left unchecked, fire can melt major structural components-such as wing spars, with obvious results. This is exactly what happened with the second B-29 prototype. The date was February 18, 1943. During the preceding months, engine overheating and engine fires became commonplace, especially at altitudes above 25,000 feet. On this day, yet another engine fire burned completely through the wing spar. Boeing test pilot Eddie Allen, the entire flight crew, and six firefighters (who were on the ground) were killed in the crash. This disaster caused the whole B-29 program to come to a halt.
Concerned that its new “super bomber” might not survive long enough to enter service, the Army took control of the entire program. Now referred to as the “B-29 Special Project,” the program was re-organized under the leadership of Brigadier General Kenneth Wolfe, and B-29 production resumed with the first of fourteen YB-29 test aircraft rolling out of Boeing’s Wichita plant on April 15, 1943.
In lieu of the earlier three-bladed propellers, the production B-29 was equipped with four-bladed Hamilton-Standard models that could be fully feathered. Plus, the General Electric computerized, remotely-fired gun system was installed, and newer versions of the R-3350 engines powered the production aircraft. The superchargers in these new engines were re-designed, as it was found that a supercharger malfunction was the cause of the Eddie Allen crash.
As with any new technology, the bugs had to be worked out, and B-29 production lagged. Things were getting dicey, because then-President Roosevelt had promised Chinese President Chiang Kai Shek that the new bombers would reach Chinese airfields by the middle of April, 1944.
Mechanics change one of the massive R-3350 engines at base in India. (Photo courtesy of the USAF)The problem was that each new B-29 coming out of the factory needed at least 54 modifications before it could be declared ready for combat. Problems with the R-3350 engines and the General Electric remote fire control system persisted to the point where General “Hap” Arnold took the reins to the whole B-29 program, personally.
Gen. Arnold’s “guidance” apparently paid off, because the first B-29s were on their way to China as of March 26, 1944. Well, not directly to China; the route took the aircraft over Africa, and they were stuck in Egypt for a week. The temperature in Cairo hit 115 degrees, and the engineers hadn’t planned on this. Further, the temperature in India (where some of the B-29s would be based) would soar to more than 120 degrees at times. Since the B-29’s engines still had a tendency to overheat under normal circumstances, something had to be done.
The solution was simply to re-design and re-work engine air-baffles and oil lines in the field. A bit of trial-and-error was involved here, and the whole project benefitted. For, if a field modification worked, it was incorporated into aircraft that were still on the production line.
Well, the April 15 deadline came; and, on that date, there were more than thirty B-29s parked at the Kharagpur, India base. By the end of that month, B-29s were flying over the famous “Hump” (the Himalyan Mountains) toward their new base in Kwanghan, China.
Ironically, the necessary supplies (including fuel) had to be flown into the Chinese base by B-29s themselves. So, a few of the aircraft were gutted and converted into fuel tankers/cargo aircraft for this purpose.
It was probably not the most efficient means to supply the base, because headwinds over the Hump could result in the use of 12-gallons of fuel in order to deliver one gallon!
It was on one of these supply flights (the first one, actually), that the B-29 was first tested in combat. One of the Superfortresses was attacked by some Japanese Ki-43 “Oscar” fighters. Although the B-29 was hit, one of the Oscars was shot down by the B-29’s tail gunner. Three of the four remotely fired gun turrets had jammed.
Well, the first B-29 bombing mission was launched on June 5, 1944. Flying from the Indian base, one hundred Superfortresses attempted to bomb rail yards in Bangkok, Thailand. Only 80 aircraft actually made it to the target. The rest either crashed on the way to the target or turned back with mechanical problems. What was worse was that a total of 18 bombs actually hit the target. The B-29 crews had yet to master the art of bombing through overcast.
Although the first B-29 mission was not a resounding success, B-29 bombing operations were about to be ramped-up dramatically. Soon B-29s would be carrying the war to Japan, itself.
