The fate of Fairchild Industries Inc.'s T46A jet trainer is hanging in midair while House and Senate members decide during the next two weeks whether to release $194 million in funds for the program that were appropriated but never released in fiscal 1986.

So far, Fairchild has received funds to produce only 10 new jet trainers, as well as two test craft, for the Air Force -- far short of plans to produce 650 new trainers costing $3.5 billion.

A clash between the House and Senate is expected over any additional money going to the trainer program. The Senate voted to permanently withdraw the 1986 funds on May 15 with an amendment to the military retirement bill. The amendment, introduced by Sen. Barry Goldwater (R-Ariz.), is expected to face opposition in conference committee from House members who support the program.

With the 1986 funds, Fairchild had planned for 22 more trainers to replace 30-year-old Cessna T37 trainers. If the 1986 funds are not released, the future of the T46A program is jeopardized.

Program funds for 1987 will be dealt with in coming weeks as part of defense appropriations bills in the House and Senate. "This is a classic battle between the House and the Senate," said Rep. Thomas J. Downey (D-N.Y.). "Barry Goldwater has cemented his legs and torso in opposition to this plane . . . but the House Armed Services Committee will be strong supporters of the plane and ultimately will prevail." Goldwater was not available for comment.

Fairchild experienced serious setbacks last year when it lost $167 million because of its troubled aircraft manufacturing business. It also sold two profitable communications companies to cover some of those losses.

To make matters worse, the Air Force suggested dropping the trainer from the budget after finding "numerous management and production deficiencies" and cost overruns at the Fairchild Republic plant on Long Island that makes the trainer. Fairchild has corrected many of those problems, according to the Air Force and Fairchild.

Fairchild has said that if it receives funding for 1987, but not 1986, it will try to "bridge the gap" through foreign military sales of the craft or modifying the A10 fighter plane at its plant. Should the program be canceled, Fairchild officials say they will have to close the plant.

Downey said the Air Force Training Command would like nothing better than the T46A trainer, but top brass at the Air Force "put the gag order on the Training Command because they want as much money as they can get for fighter aircraft."

Sen. Alfonse M. D'Amato (R-N.Y.), a member of the Senate appropriations subcommittee on defense, said it would cost taxpayers "at least $1 billion" to cancel the program, in part because of increased costs to refurbish the aging T37s. One Air Force official said putting the program on hold for several years until funding is available and then having companies bid to produce planes using the Fairchild design has been suggested.

Gen. Lawrence Skantze, commander of Air Force Systems Command, called the T46A a "good airplane," but said the issue boiled down to money and priorities. "The Air Force can't afford it on a prioritized basis with a sharp reduction in its budget," he said. Since the defense budget of $320 billion was submitted, Congress will cut it by at least $25 billion, he said.

Congress can expect a fight from the Air Force if it suggests money be removed from a higher-priority fighter program to fund the T46A, he said.

Fairchild Industries Chairman Emanuel Fthenakis said he didn't understand why the T46A trainer remained out of the Air Force budget when officials told him it was needed.