The device, called the Traffic Alert and Collision Avoidance System, monitors radar signals to detect a potential collision and, in extreme cases, tells the crew to climb or dive immediately.

The incident began when a computer system called T-CAS, for Traffic Alert and Collision Avoidance System, told the pilot that another airplane was coming toward him.

The Federal Aviation Administration is studying the possibility that a larger number of commercial aircraft would eventually need these Traffic Alert and Collision Avoidance Systems, known as TCAS.

At issue is an electronic device, the Traffic Alert and Collision Avoidance System, or TCAS.

Commuter planes and air taxis with 20 or more passenger seats would have four years to install the Traffic Alert and Collision Avoidance Systems.

The computerized Traffic Alert and Collision Avoidance System, or TCAS, couldn't care one way or the other about the fate of its charges.

The approach triggered the 727's Traffic Alert and Collision Avoidance System, or T-CAS, which advised the crew to dive, climb and dive again to get away.

Known as a Traffic Alert and Collision Avoidance System, or TCAS, the on-board systems communicate with each other and plot out evasion maneuvers for each airplane.

The Traffic Alert and Collision Avoidance System, or TCAS, has had unfavorable reviews in the aviation press.

It has the Traffic Alert and Collision Avoidance System II on board.