WASHINGTON (AP) _ An American Airlines jet turned off course and crashed into a mountain in Colombia last year after the plane's crew became confused about their location and then had a misunderstanding with the ground controller, documents released Tuesday indicate.

The Boeing 757 from Miami slammed into a mountainside Dec. 20, 1995, killing 160 people, when it apparently turned back toward a navigational beacon it had already passed.

Colombian investigators have reached no conclusion on the cause of the disaster, but a set of investigators' reports was released Tuesday by the National Transportation Safety Board.

While pilot Nicholas Tafuri, 57, had flown the route often, the plane was in the hands of first officer Don Williams, 39, an experienced pilot but making his first approach to Cali.

Controller Nelson Rivera Ramirez told investigators he believed he had cleared the plane for landing at Cali, passing over a radio beacon at Tulua, 55 miles north.

The crew failed to report passing Tulua and cockpit discussion indicates confusion over whether they were to approach Cali directly or pass over Tulua first.

When the plane crew reported they were 38 miles from Cali and asked if they should head for the Tulua beacon, the query made no sense, ground controller Rivera told investigators, because the distance indicated the plane had already passed the beacon. So Rivera repeated the clearance to land.

Asked what he would have said to a Spanish-speaking pilot in the same location who asked whether he should head for Tulua, Rivera said ``he would have told them that their request made no sense, that their request was illogical and incongruent, but he did not know how to convey these thoughts ... in English.''

Rivera said that because of their distance from Cali, he thought the pilot had simply failed to report passing the beacon and ``had no doubt that the flight was proceeding toward runway 19 and ... never thought to verify the aircraft's position with respect to the center line'' of the runway.

At the same time, with the plane past Tulua and headed toward Cali, the cockpit microphones indicate confusion about there the craft was:

Williams: ``Uh, where are we... we goin' out to ...''

Tafuri: ``Lets go right to, uh, Tulua first of all. OK?''

Williams: ``Yeah, where we headed?''

Tafuri: ``... I don't know what's this ULQ? What the, what happened here?'' (ULQ is the radio call sign for Tulua).

A few seconds later Tafuri identifies the call from Tulua, adding it ``just doesn't look right ... I don't know why.''

Williams: ``Left turn, so you want a left turn back around to ULQ.''

Tafuri: ``Nawww. ... Hell no, let's press on to ...''

Williams: ``Well we're, press on to where though?''

Tafuri: ``Tulua.''

Tafuri then made the radio call that so confused Rivera, asking if they should head for Tulua before approaching the Cali runway.

Rivera replied: ``... You can use, runway one niner. What is altitude and the (distance) from Cali?''

Tafuri: ``OK, we're 37 (miles away) at 10,000 feet.''

The plane then apparently began the left turn that led it into the mountainside.