The twin-engine, two-seat fighter, which includes radar-eluding "stealth" technology, is intended to serve well into the next century as the Navy's key aircraft for attacking ground targets. It is designed to replace the Navy's aging A-6 fleet, which cost the Pentagon about $20 million each in 1986, shortly before production stopped.
Navy officials privately blamed sloppy editing by the House Appropriations Committee for revealing that the service wants to spend $10.2 billion to build 106 A-12s between now and 1994. Other references to the cost of the plane have been deleted from all other transcripts of secret congressional hearings before they were made public.
The Navy had no official comment. The committee also declined to comment on release of the figures.
The Navy's goal of buying 450 planes probably will be cut as the Pentagon budget shrinks, pushing the per-plane price above the $96.2 million figure cited in the congressional testimony, Navy officials said.
Until now, relatively few members of Congress, with access to the contents of the Pentagon's secret "black" budget, have known the A-12's cost.
Unlike the Air Force's secret and fledgling advanced tactical fighter - estimated to cost $90 million each - the Navy refuses to even list the A-12 on its quarterly reports to Congress detailing production programs. No public drawings of the plane, scheduled to fly for the first time later this year, are available.
A former Navy official who worked on the A-12 said criticism of the service's development of the F-18 - its newest fighter, which has had numerous technical problems - had helped persuade the Navy to keep as much of the A-12 secret for as long as possible. "There's been a lot of deliberate misinformation put out about the program by the Navy," said the official, who did not want to be identified.
The newly released documents quote the admiral in charge of aircraft as telling Congress: "The A-12 is a revolutionary program which will improve our all-weather attack capability. . . . It will incorporate significant stealth characteristics and become the primary striking platform of the carrier battle groups."
Built largely of plasticlike composites that do not reflect radar waves, it ''will be able to penetrate even the most heavily defended enemy areas to reach its targets," he said.
The Marine Corps had planned to buy the A-12, but because of its rising cost, the corps instead will buy F-18s - for $30 million each - for its land attack missions.