FAA History Lesson -- June 8-14

From the FAA Historical Chronology, 1926-1996...

”Jun 8-14, 1983: A Joint System Program Office (JSPO) representing the National Weather Service, FAA, and the Air Force awarded two competitive contracts to develop pre-production models of the Next Generation Weather Radar (NEXRAD). The contracts would remain in effect until July 1986, after which one of the firms would be selected for production. NEXRAD would have the ability to "see" inside storms and measure the velocity and direction of wind-driven precipitation and other particles suspended in the air. The system was based on the Doppler effect, which permits an object's speed and direction to be determined by the lengths or frequency of the light, sound, or radio waves it emits.

The U.S. government had been investigating the potential of Doppler radar since the 1950s. In Apr 1977, joint NEXRAD testing was begun by the Air Force and the Commerce Department's National Weather Service. FAA formally joined the program in Dec 1977, due to the tests' success and perhaps also the crash of a DC-9 in a thunderstorm (see Apr 4, 1977). In Aug 1979, the Departments of Commerce, Transportation, and Defense formed a Joint System Program Office with the goal of developing a national network of NEXRAD radars and processing equipment. The Commerce Department, which planned to buy and operate most of the radars, was given the lead role (see Feb 28, 1994).

Initially, NEXRAD had been intended to cover both en route and airport needs, but Project JAWS (see May 15-Aug 13, 1982) produced data on wind shear microbursts that prompted FAA to conclude that separate airport systems would be needed. To learn more about how Doppler radar could by applied to the low-level wind shear hazard, FAA conducted Project CLAWS (for classify, locate, and avoid wind shear) in the Denver area from Jul 7 to Aug 13, 1984. FAA contracted with the National Center for Atmospheric Research to provide daily microburst forecasts, Doppler radar surveillance, and real-time advisories of microburst activities. During CLAWS, pilots gave detailed feedback on the effectiveness of the system. On Sep 16, 1985, FAA signed an agreement with the Commerce Department under which FAA would contract with the Sperry and Raytheon corporations to identify how NEXRAD systems would need to be modified to develop terminal Doppler radar. (See Aug 2, 1985.) ”

I think I’ve said enough about the safety problems of interpreting NEXRAD data in the past and I’m sure that I will do so again in the future. For today, I’d like for you to think about the things that our government does to promote commerce. As I’m sure you noticed, NEXRAD was a joint effort between Commerce, Transportation and Defense. Some people probably haven’t thought of the National Weather Service being within the Department of Commerce but once you do, it makes a lot of sense. Agriculture, forestry, tourism...weather touches everything -- especially commerce. Think about how these national systems promote commerce. Think about who would do them -- nationwide -- if the government didn’t.

And in case you didn’t remember the events of April 4, 1977...

”Apr 4, 1977: A Southern Airways DC-9 crashed near New Hope, Ga. The pilot attempted an emergency landing on a highway, but the aircraft broke apart and caught fire. The accident killed 62 of the 85 persons aboard, as well as 8 persons on the ground. In addition, one passenger and one person injured on the ground died about a month later. The National Transportation Safety Board cited the probable cause of the crash as the total and unique loss of thrust after the engines ingested massive amounts of water and hail as the aircraft penetrated an area of severe thunderstorms. As contributory causes, the NTSB listed: failure of the airline's dispatch system to provide up-to-date severe weather data; the captain's reliance on airborne weather radar to enter a thunderstorm area; and FAA's lack of a system for disseminating real-time hazardous weather warnings. (See May 19, 1977.) “


Don Brown
June 9, 2008