Northrop YB-35 - Operational History

Operational History

The Army Air Force had originally ordered 200 production model B-35s. Since Northrop's facilities were not up to the task of producing them, the Glenn L. Martin Company agreed to undertake mass production. This proved irrelevant when the aircraft had too many development problems. Even disregarding these, so many of Martin's engineers had been drafted by 1944 that Martin pushed the first delivery date back to 1947. Seeing that it would almost certainly never be ready in time for the war, the Army Air Force canceled the production contract, though the Air Technical Services Command continued to run the program for research purposes.

Actual flight tests of the aircraft revealed several problems: The contra-rotating props caused constant heavy drive-shaft vibration and the government-supplied gearboxes had frequent malfunctions and reduced the effectiveness of propeller control. After only 19 flights, Northrop grounded the first XB-35; the second aircraft was grounded after eight test flights. During this time, the contra-rotating propellers were removed and replaced with four-blade single-rotation propellers. In addition to having continued drive shaft vibration problems, the new single-rotation props greatly reduced the aircraft's speed and performance. Furthermore, the intricate exhaust system turned into a fiasco to maintain. After only two years of use, the engines already showed signs of metal fatigue.

In the end, the program was terminated due to its technical difficulties, the obsolescence of its reciprocating propeller engines, and the program being far behind schedule and over budget. Another contributing factor to the program's failure was the tendency of Northrop to become engaged in many experimental programs, which spread its small engineering staff far too wide. While the competing propeller-driven B-36 was obsolete by that time and had just as many or even more development problems, the Air Force needed a very long range, post-war atomic bomber to counter the perceived Soviet threat. It had more faith that the B-36's "teething" problems could be overcome, compared to those of the new and radical "Flying Wing", the unofficial name that was later associated with all the Northrop "all-wing" designs.

There are long-standing conspiracy theories about the cancellation of the Flying Wing program; specifically, an accusation from Jack Northrop that Secretary of the Air Force Stuart Symington attempted to coerce him to merge his company with the Atlas Corporation-controlled Convair. In a 1979 taped interview, Jack Northrop claimed the Flying Wing contract was cancelled because he would not agree to a merger because Convair's merger demands were "grossly unfair to Northrop." When Northrop refused, Symington supposedly arranged to cancel the B-35 and B-49 program. Symington became president of Convair after he left government service a short time later.

Other observers note that the B-35 and B-49 designs had well documented performance and design issues while the Convair B-36 needed more development money. At that time, it appeared the B-36 program might be cancelled as well as the B-35. The USAF and the Texas Congressional delegation desired to have a production program for the large Fort Worth aircraft production factory, and Convair had much more effective lobbyists in Washington DC. The Northrop Corporation was always a technological trailblazer but the independent nature of Jack Northrop often collided with the political wheeling-and-dealing in Washington that tended to run huge military allocations. Consequently, the B-36 prevailed. Furthermore, earlier the same year, when the YB-49 jet bomber was cancelled, Northrop received a smaller production contract for its F-89 Scorpion fighter as compensation for the lost Flying Wing contract.