Flight Alert Devices Ordered

WASHINGTON — The government will order the nation’s airlines to install collision avoidance systems aboard their planes in a move that could make flying safer, Federal Aviation Administration chief Donald D. Engen said today.

Engen said the Traffic Alert and Collision Avoidance System--TCAS--would reduce the chances of in-flight collisions. The system can alert the pilot of an impending collision and advise whether the plane should go up or down to avoid it. It is estimated to cost between $50,000 and $75,000 for each plane.