Aegis Malfunctioned a Month Before Iran Air Disaster

The Pentagon confirmed Thursday that about a month before the July 3 downing of an Iran Air jet by the U.S. cruiser Vincennes, a key component of the Navy ship’s $525-million Aegis system suffered “minor degradation” that prevented it from functioning properly for at least 16 days.

The malfunction in the system, which identifies the position and speed of aircraft in the vicinity of the vessel, could be repaired only after a special part was flown to the cruiser in the Gulf of Oman.

The breakdown of the Vincennes’ critical Spy-1 radar raises new questions about the reliability of the system that was central to the decision by Capt. Will C. Rogers III to fire on the airliner seven minutes after it took off from an airfield in Bandar Abbas, Iran, and began crossing the Persian Gulf. Rogers has said that, based on the information provided by the system, he believed the craft was an Iranian fighter jet.

Tapes Arrive for Analysis

Confirmation of the Aegis equipment problem, which was repaired by sailors aboard the Vincennes on June 6, came Thursday as computer tapes from some of the Vincennes’ 21 separate recording tracks arrived at the Navy Surface Warfare Center in Dahlgren, Va., for analysis.

A team of Navy investigators led by Rear Adm. William M. Fogarty will use the tapes to help reconstruct the events leading up to the moment the Vincennes fired two missiles at the airliner, which exploded, killing all 290 aboard.

As U.S. officials sifted through evidence they still consider preliminary, Defense Department spokesman Dan Howard backed away from earlier Pentagon statements that the airliner was as much as 5 miles outside the commercial flight corridor when it was shot down.

In a revised statement, Howard said, “The aircraft was at least 4 1/2 miles off the center line of the airway and in that regard could be considered to be off the normal track of commercial traffic.”

But the Pentagon spokesman conceded that the width of such air corridors varies from country to country and that pilots were urged, but not required, to remain in the center of the corridor.

“There is still some confusion . . . as to how wide the airway is,” Howard said.

On Capitol Hill, where the incident has begun to focus new attention on the risks of U.S. policy in the gulf, Senate Majority Leader Robert C. Byrd (D-W.Va.) complained that the debate over the downing of the Iranian airliner had become bogged down in technical details.

‘Our Poor Captains’

“We’re missing the point,” Byrd told reporters. “What is needed is a new evaluation of the mission. We are operating in a lake. We have a $1-billion Aegis cruiser chasing fast-traveling Boghammar boats.

“Our poor captains have to make life-or-death decisions on fast-paced data coming in within minutes or seconds,” he added.

In a letter Thursday to Defense Secretary Frank C. Carlucci, Byrd also asked that the Pentagon consider stepping up the operations of U.S. and Saudi warplanes over the gulf in the wake of Sunday’s fatal error.

“It would appear that the presence of air cover, either surveillance or combat aircraft, could have helped to prevent the recent tragedy. We would appreciate your attention to this question and the related question of whether we are receiving adequate cooperation from friendly states in the Persian Gulf area,” the letter said.

No Increased Coverage

However, senior national security officials have decided against providing increased coverage of the gulf by U.S. Navy aircraft.

“No one believes the threat (to U.S. forces in the gulf) has changed, and consequently, they are not contemplating force structure changes,” said one knowledgeable Pentagon official, who added that senior military officials do not consider it “cost effective” to keep planes flying around the clock over the gulf.