Attorneys for the families of four pilots killed in midair collision over Kearns three years ago played an audio tape Monday in U.S. District Court of conversations between air traffic controllers and pilots in the sky at the time of the collision.

The dramatic tape launched the first day of trial in Judge Thomas Greene's court.Survivors of the four pilots - two from each plane - killed in the collision are suing the federal government for $5 million and reasonable damages for the conduct of the Federal Aviation Administration, alleging negligent air traffic control on the day of the collision.

Plaintiff attorney Robert Wallace noted that federal guidelines require controllers to make safety their first priority, followed by an orderly and expeditious flow of traffic. He charged Monday that air traffic controllers put a higher priority on expeditious flow of traffic than on safety the day of the collision, Jan. 15, 1987.

In opening statements, Wallace noted that air traffic around the Salt Lake International Airport was light to moderate in the hour before the 1 p.m. collision.

"It was so light that the supervisor in TRACON (terminal radar approach control, the air traffic control center) left," Wallace said. The traffic was so light that one controller was watching two sectors, Wallace said.

Despite the light traffic, Salt Lake air traffic controllers failed to warn Sky West Flight 834, a metroliner from Pocatello carrying 10 people, that a small plane was in the area.

Playing back of the audio tape of conversations between SkyWest pilots and TRACON, Wallace pointed out that the TRACON controller drew the SkyWest pilot's attention away from the area containing the smaller plane, a Mooney.

The controller advised SkyWest to look for two Western Airline jets in a landing pattern and to plan to land after the first jet and before the second jet.

At 12:50:35 - less than 1 1/2 minutes before the collision - TRACON advised SkyWest to look for the second Western jet to the south at 7500 feet.

"The pilot's attention was diverted away from the Mooney," Wallace said.

The SkyWest pilots spent the remaining precious seconds before the collision looking in a different direction for the second Western jet. At 12:51:07, SkyWest pilots were looking in the opposite direction for the Western jet.

At 12:51:15, TRACON instructed the SkyWest plane to "turn left heading zero seven zero."

"Basically turning this metroliner right into the apparent path of the Mooney," Wallace said.

A tape of what was seen on the radar screen that day shown in court Monday clearly identifies the Mooney as a triangular blip on TRACON's radar.

Wallace noted that despite the Mooney's presence on the screen, air traffic controllers did not alert any of their planes and jets of its presence.

"The first Western plane flies right over the Mooney and no traffic advisory is given," Wallace said. "We submit to the court that there was an emphasis on the expeditious flow of traffic that day rather on the primary concern - the safe flow of traffic."

Playing the tape of the collision, Wallace said, "What you have just heard was an expletive from one of the pilots and then the crash." At 12:51:59, Wallace said, the accident had happened. Pilots and passengers had died.

The rolling tape captured the confusion that reigned in TRACON after SkyWest disappeared from the screen. A controller repeatedly called out, "SkyWest No. 834 - Salt Lake, SkyWest No. 834 - Salt Lake."

The controller asked others, "Do you see SkyWest No. 834 out there. What happened to him? I can't figure out what happened to him." Then calling to his controller colleagues, "I am in trouble down here. I have lost SkyWest No. 834 on the screen."

The National Transportation Safety Board has already ruled that pilot Paul Lietz, apparently an instructor in the Mooney, failed to maintain proper lookout causing the collision.