Stress of first-time combat blamed for downing of Iranian jet

The stress of first-time combat caused the USS Vincennes crew to shoot down an Iranian airliner in the mistaken belief that it was an F-14 jet fighter. That's the conclusion of a military inquiry into last month's Gulf tragedy, according to published reports.

The inquiry has determined that the Vincennes' fancy Aegis radar did not malfunction. Instead, skittish radar operators wrongly interpreted information on the screens in front of them, and identified the oncoming blip of Iran Air Flight 655 as hostile, according to press reports.

Computerized records from the Vincennes have apparently established that the Iranian airliner was traveling much more slowly than thought on the day of the attack, and was climbing instead of descending in an attack profile.

It is still not clear whether Vincennes Capt. Will Rogers III was himself at fault in ordering destruction of the civilian plane. Information about speed and altitude would not have been shown on the large display screens he would likely have been watching. Instead, that information was available to Vincennes radar operators, and may or may not have been passed along accurately to their commander.

It is also not clear what the inquiry has determined about the conflicting transponder signals the Vincennes says it received. Transponder signals are, in essence, what a plane uses to announce its identity to the outside world, and Iran Air 655 was sending both a civilian and military transponder signal, Pentagon officials say.

The Department of Defense had no immediate official response to the disclosures about the inquiry. A number of Pentagon officials said yesterday that they were not sure the inquiry had completed its work, and declined comment pending disclosure of more details.

President Reagan, at a brief press conference yesterday, also declined comment, saying ``neither the military nor my office has received that report.''

Running radar-picket duty in the Gulf, as the Vincennes was doing, is indeed a stressful job, Pentagon officials agree. Unlike the all-out conflict for which Aegis radar is designed, the Gulf situation is half-peace and half-war, meaning radar operators are constantly watching a swarm of tracks, not knowing which ones might turn out to be hostile.

Other US Navy ships have unholstered their missiles and prepared to shoot at blips, which were identified as civilian in the nick of time. In this sense, the Vincennes incident was simply an accident waiting to happen, military officers say.

Any edginess on the part of the Vincennes crew could well have been exacerbated by their knowledge of the ship's value.

The USS Stark, struck last year by Iraqi missiles, was a relatively inexpensive frigate, the economy car of the Navy. Aegis cruisers such as the Vincennes, on the other hand, are the Mercedes of the surface fleet, designed for general war at sea and worth over a billion dollars each.

Many Navy admirals have bitterly criticized the decision to send Aegis cruisers to the Gulf for just that reason. Less complicated ships could do the job just as well, they say, with corresponding less risk of loss of US taxpayers' money.