Two of the nation's worst commercial air disasters of the past 10 years -- the crash of a Delta Airlines jumbo jet at the Dallas-Fort Worth International Airport in 1985 that took 137 lives and the 1982 downing of a Pan American World Airways jet in New Orleans that killed 146 -- were blamed on the same thing: wind shear.
Wind shear is a weather condition that involves the sudden and dramatic change in wind direction that can push a plane to the ground. Engineers at the Westinghouse Electric Corp. complex near Baltimore-Washington International Airport are developing a radar designed to detect such conditions in time for a pilot to steer away.
The new radar is in its development stage, said Terry R. Patton, a Westinghouse program manager, but it will probably work something like this:
The pilot would have something similar to a television screen in the cockpit. The screen would display weather conditions in various colors, with red likely being an indication of dangerous wind shear. There would also be a sound warning -- a bell or buzzer -- to attract the flight crew's attention if wind shear is detected.
The radar would "see" the usually invisible weather condition a mile or two ahead, said Mr. Patton, "in plenty of time for the pilot to turn away."
He said that wind shear is usually an atmospheric condition about a half-mile in diameter that is like a hole in the sky where the wind drops straight down. Planes now have sensors to detect movement in the plane to tell the pilot when the craft is in a wind shear.
Westinghouse is testing the new equipment on a plane in its corporate fleet. On Aug. 12, Mr. Patton said, it will be installed on a Continental Airlines A-300 aircraft based at Denver's Stapleton Airport. He said this particular plane was picked because it flies into airports in Denver, New Orleans and Miami, where wind shear is more common than in other parts of the nation.
The Federal Aviation Administration has passed regulations requiring all commercial airlines be equipped with wind shear radar by the end of 1993. There are 4,600 planes in the nation's commercial fleet, according to the FAA.
"We're expecting this to be a big business for us," said Mr. Patton, who also noted that some other companies, including Bendix Corp., are developing similar radar systems.
Ted Lopatkiewicz, a spokesman for the National Transportation Safety Board in Washington, said that 575 deaths were attributed to wind shear between 1970 and the Delta crash in 1985. Any device that would warn pilots ahead of time to enable them to avoid it would be a great benefit to airline safety, he added.