But the Federal Aviation Administration said the cause of the accident was a buildup of ice on the wings when the plane entered an area of unusual weather conditions called " super-cooled drizzle drops ."
22.
His testimony followed that of meteorologists earlier this week, who said the plane may have run into an unusual weather condition, a fine mist that freezes on contact with a solid, described by one expert as supercooled drizzle drops.
23.
In the opening day of testimony before the National Transportation Safety Board, one of the experts, Dr . John Marwitz, a professor of meteorology at the University of Wyoming, argued that the design of the ATR-72 did not make it particularly vulnerable to the rare precipitation known as " super-cooled drizzle drops ."
24.
Using Beechcraft twin-engine propeller craft as an example, he said that if The New York Times'investigation had focused on a different aircraft manufacturer, " they would find an equal, similar set of anecdotal evidences to suggest that super-cooled drizzle drops are important, that this is not a problem unique to high-performance aircraft or low-turbulence wings; it's all of them ."
