Who would have thought that a company that didn’t even know what a jet engine was (Westinghouse) and one that had never developed a carrier-based airplane (McDonnell) could have succeeded in producing a fully operational carrier-based jet fighter on the first try during World War II? But the more experience engine and airplane manufacturers were too involved in production contracts and more conventional development programs, so the Navy gave them the assignment.
The Army got the plans for the Whittle engine, which was actually running in England, and gave them to General Electric. The Army then contracted with Bell Aircraft, an experienced airplane manufacturer, to design a land-based jet fighter using two of those engines. The resulting P-59 was, by all accounts, a dog.
Westinghouse created its engine from scratch with no outside assistance due to the secrecy imposed. It had an axial-flow compressor, which was the future, instead of the centrifugal compressor used in the Whittle engine, a dead end from the standpoint of increasing thrust significantly. The original Yankee engine, only 19 inches in diameter, worked well enough to demonstrate that the configuration was sound. One was flown under an FG-1 Corsair at NATC Patuxent River beginning in January 1944.
After development and qualification, two flight-rated versions of the Yankee powered the Navy's first jet fighter, the McDonnell XFD-1 Phantom. It became the J30.
So Westinghouse scaled up the 19-inch diameter engine to 24 inches for more thrust. It was subsequently designated the J34. It powered the McDonnell F2D Banshee and the Douglas F3D Skyknight (which necessitated the change of the McDonnell designation from D to H; the original Phantom became the FH and the Banshee, F2H). And also the Vought F7U-1 Cutlass, with the addition of a government-furnished afterburner.
The Navy needed still bigger, more capable jet fighters so it held a competition for an even more powerful engine. Picking Westinghouse to scale its engine up again as the J40 must have seemed like a no-brainer. The J40-WE-6 was to power the A3D Skywarrior and the J40-WE-8, which was essentially the -6 with a Westinghouse-developed afterburner added, was to provide the thrust for the Douglas F4D Skyray, the McDonnell F3H Demon, and the Grumman F10F Jaguar.
Although production and support of the J34 continued, Westinghouse eventually exited the aircraft engine business.
Where did Westinghouse go wrong? One theory is the early successes did not result in a problem-solving culture within the engine division. Another is that the company did not continue to invest in technology and innovation like P&W and General Electric did. For example, to improve compression ratio for better thrust to weight and lower specific fuel consumption without incurring compressor stalls, P&W developed the two-spool engine and General Electric, the variable inlet guide vane concept. Westinghouse just kept scaling up the basic design, which eventually proved inadequate to the task.