WASHINGTON — Commuter aircraft, which carry nearly 30 million people a year, would have to be equipped with "black box" recorders to assist in crash investigations under a regulation proposed Thursday by the Federal Aviation Administration.
The recorders--a flight data recorder to monitor aircraft performance and a cockpit voice recorder to preserve crew conversations--are already required on larger jetliners.
Sources who declined to be identified gave details of the regulation in advance of its formal release.
The National Transportation Safety Board for years has urged that commuter planes, which normally have 30 or fewer seats, have such recorders because the devices often are essential in pinpointing the cause of an accident.
In recent years, at least a half-dozen accident investigations were hampered because the plane had no such devices, NTSB spokesman Mike Benson said.
Increase in Passengers
Additional focus has been put on the issue in recent years because of the sharp increase in the number of people who fly on commuter aircraft--28.4 million people in 1986, about twice as many as in 1981, according to the Regional Airline Assn. No figures were available for last year, although the number was expected to have increased.
The FAA's proposed rule, which is expected to be made final within a few months, would require a cockpit voice recorder on turbine-powered commuter planes of six seats or more within two years.
It also would require flight data recorders on all turbine-powered commuter planes of 20 or more seats and all new turbine-powered commuter planes of 10 or more seats.
Operators of planes having 10 to 19 seats would not have to install existing aircraft with the devices, although larger commuter planes would have to be retrofitted within two years of a final rule.
Perform Various Functions
A flight data recorder keeps track of air speed, engine power and plane position during flight, while the cockpit voice recorder monitors conversations in the cockpit on a continuous 30-minute loop recording.
The recorders, which actually are orange in color, have been dubbed "black boxes" because often they are found amid the charred wreckage after an aircraft accident. They have for years been required on large jetliners of more than 30 seats.
The commuter industry has objected to requiring the recorders in smaller planes because of costs. But those favoring such devices have argued that both voice recorders and flight data recorders can be designed specifically for smaller aircraft at a lower cost.