The loss of the EgyptAir flight and the Learjet carrying Payne Stewart only a week earlier are two tragic examples of the need for an effective air-traffic monitoring system. These follow a string of crashes over the past decade in which the on-board flight data recorders and cockpit voice recorders were difficult to recover and did not yield much information on what went wrong and why.

Much more data would be available more quickly, and future accidents might well be prevented, if aircraft were monitored in flight the way spacecraft are monitored in orbit. All satellites transmit a continuous stream of data by radio to their ground-control centers, providing real-time information on their mission performance. Telemetry has been used for decades to monitor robotic spacecraft. Yet we still send aircraft carrying people across an ocean without telemetered data flow and frequently without continuous voice communications.

A 21st century air-traffic control system should include comprehensive monitoring of all instrumented aircraft in flight. Global air-traffic control and monitoring centers could then maintain a continuously updated record for each aircraft in flight with voice recording and hundreds of status and event points. If various data (i.e., position, fuel pressure and level, temperatures, structural strains, etc.) were available at a ground-control center for an aircraft in flight and subject to analyses, many problems might be anticipated and repairs made or emergency procedures put into effect.

All of the communications and data-processing technologies necessary to implement a comprehensive aircraft monitoring system are available. The need for and value of such a system are obvious. The United States and other countries should develop and deploy a global aircraft monitoring system without delay.

BURT EDELSON

Chevy Chase