Safety experts are puzzled by a curious trend: in recent years fewer passengers on U.S. commercial flights are being killed, but their are more incidents involving damage to planes. Whatever the reason, experts see those incidents as an opportunity to study the causes and develop procedures to avoid fatalities in the future.

• There was not a single fatal airline accident in 1998 -- although one airline employee was killed when he was struck by a propeller.

• In 1999, the only fatal crash occurred when an American Airlines jet crashed off the end of a runway in Little Rock, Ark., killing 11 -- and one ramp worker was also killed by a spinning propeller.

• But through last November, there were 47 incidents causing either serious injury or significant damage to an aircraft -- well above averages in the early 1990s.

• Incidents involving significant aircraft damage were limited to an average of six cases a year in the early 1990s -- compared with an average of more than 20 in the past three years.

Sources: Alan Levin, "Rise in Airline Mishaps Might Not Be Bad Sign," and "Airline Deaths Decline, But Injuries on the Rise," USA Today, January 12, 2000.

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