A House subcommittee yesterday threw into jeopardy the Air Force's most desired new weapon, the F-22 jet fighter, voting to cut $3 billion that had been requested to produce the first six planes.

The action, which stunned Air Force generals, is likely to force a major debate in Congress over whether the United States can afford the F-22 -- in addition to two other new jet fighters in the works -- and still meet the challenge of enhancing defense readiness and training air crews.

Faced with tough spending choices, the defense appropriations subcommittee redirected $1.8 billion in the fiscal 2000 spending bill to pay for more of the Air Force's current F-15 and F-16 fighters as well as tanker aircraft and incentives to keep pilots from leaving the military.

The remaining $1.2 billion would go for research and development to keep the F-22 program alive while the Pentagon reassesses it. Rep. Jerry Lewis (R-Calif.), the subcommittee chairman, said the decision would merely ensure a "pause" in the F-22 program, but he left little doubt which way he was leaning.

"It's very likely the rethinking that this decision will pressure will cause the people within the [Defense] Department to say, `Hey, this doesn't make sense, so what direction should we take?' " he said.

Rep. John P. Murtha (Pa.), the panel's ranking Democrat, supported the cut. "We think we have a package that's dramatic, that will change the direction of the Air Force, and we think we can sell this to the Senate," he said.

The Senate version of the bill includes $3 billion for F-22 production. But a senior staff member said there is enough ambivalence in the Senate to spell the fighter's demise if the full House moves to kill it.

The Air Force has promoted the plane as essential to maintain control of the skies. Eighteen years in the making, the aircraft is intended to succeed the F-15 and to serve as a technological test bed toward development of a less expensive, multi-service Joint Strike Fighter.

In a terse official reaction, the Air Force offered to work with the House members to address their concerns.

"It took us completely by surprise," said one senior officer. "It could have a huge impact."

The F-22 uses stealth technology to evade radar and can "supercruise" at Mach 1.5 -- one and a half times the speed of sound -- without fuel-guzzling afterburners. Its advanced cockpit displays would allow pilots to identify and attack enemy aircraft well beyond visual range.

But at an estimated $187 million per plane, the F-22 also would be the most expensive fighter ever produced. Its price tag has more than doubled as a result of problems in developing its revolutionary airframe and advanced avionics.

In early 1997 the Pentagon decided to reduce the planned purchase of F-22s over the next two decades from 438 to 339 planes. Congress also moved to rein in the program, imposing caps of $18.9 billion on development and $43.4 billion on production. But costs have continued to grow.

Lewis said the F-22 made sense when the United States faced a Soviet superpower capable of developing ever more sophisticated aircraft. But, he said, other problems have become more pressing in the past decade, including difficulties retaining Air Force pilots and shortages in reconnaissance, refueling and transport aircraft.

The fiscal 2000 defense spending bill approved yesterday by the subcommittee totals $266 billion. It provides for a 4.8 percent military pay raise. It allocates an additional $453 million over the administration's request to boost stocks of spare parts. It also increases spending for equipment and weapons modernization programs by $9 billion over the fiscal 1999 level.