The military investigation of last summer's shootdown of an Iranian airliner found the Navy cruiser Vincennes clearly responsible for the accident, but the Pentagon's brass decided no disciplinary action was warranted.

In a case that went all the way up to then-Defense Secretary Frank Carlucci and Adm. William Crowe, chairman of the Joint Chiefs of Staff, the Pentagon announced last August the ship's crew had made several understandable mistakes.The military board of inquiry reported the Vincennes was in the midst of a surface battle with Iranian gunboats when Iran's Flight 655 took off from Bandar Abbas, and the ship's crew misidentified the commercial plane as a hostile jet fighter flying a direct course for the cruiser.

The board also concluded that Iran bore a substantial measure of blame for allowing a commercial plane to take off from an airport used by both commercial and military aircraft during the middle of a battle.

Carlucci and Crowe said they had concluded the crew acted as they did because they weren't about to take any chances with their own ship's safety. That attitude had been reinforced by the fate of the USS Stark, which was struck by two missiles in May 1987 when accidentally fired upon by an Iraqi jet fighter. Thirty-seven crewmen were killed.

"It was only prudent for Capt. (Will) Rogers to assume that the (radar) contact was related to his engagement with the Iranian boats until proven otherwise," Crowe said on Aug. 19.

"The proof never came," he said. "I believe that given the operating environment, Capt. Rogers acted reasonably and did what his nation expected of him."