Japan is beating up on U.S. business, from cars to computers to TV sets, and much else besides; the trade deficit with Japan is $50 billion a year. Yet the administration is considering a deal that would transfer significant U.S. aerospace technology to that Asian nation.

That prospect has many members of Congress upset - and with good reason. Even some Republicans are lining up against the president.At stake is a next-generation warplane known as the FSX. Essentially, Japan is saying that it won't buy any of the new aircraft unless it is allowed to help design and build the planes for deployment in the late 1990s.

The deal worked out under the Reagan administration and being studied by Bush's team would give the United States about 35-45 percent of the $7 billion development and production work. In return, Japan would get the necessary advanced technology, originally developed for the U.S. Air Force F-16 fighter.

If the United States won't enter into such a partnership, the Japanese say they will start their own aerospace and defense industry. Under no circumstances will Japan buy any more warplanes wholly built in America. In essence, it's slightly less than half a loaf - or none.

But many members of Congress believe this is one deal the United States should pass up, saying that 35-45 percent of $7 billion isn't worth it.

Certainly there are serious questions. As long as the trade imbalance with Japan is so high, the Japanese ought to be willing to buy their planes from America. A partnership will result in transferring technology from the one area where the United States remains supreme - in aerospace - to Japan.

Critics are concerned that the deal will only help Japan in the future to compete against the United States in the international aviation market. They say Japan's primary concern is not defense but catching up with the United States in aerospace industries.

Rep. Mel Levine, D-Calif., put it succinctly: "We can't prevent Japan from building its own domestic aerospace and defense industry. But I see no reason to hand them the blueprints at a very modest price."

Japanese leaders want a U.S. decision before March 31. But unless more compelling reasons can be offered for the warplane plan, the administration should turn thumbs down on this one.