Business Notes AIRLINES

During the past few months, the skies have seemed increasingly treacherous for commuter planes. The craft, defined as capable of carrying up to 30 passengers, have been involved in seven crashes and 56 deaths since November. By comparison, during the period 1980-86 commuter airlines averaged only 26 fatalities a year. Last week T. Allan McArtor, chief of the Federal Aviation Administration, announced a six-month probe into what appears to be an ominous trend. FAA inspectors will single out the 20% of 173 U.S. carriers with the worst safety problems, then make in-depth field inspections of those airlines. One bit of suspicious evidence has already turned up: apparently the first indication of cocaine use by a commercial pilot who was involved in a fatal crash. The National Transportation Safety Board said it discovered traces of the drug in the blood and urine of Pilot Steve Silver, whose Continental Express commuter plane crashed in January near Durango, Colo., killing nine.