Aircraft

NASA is to fund development of a prototype clear-air and severe storm turbulence prediction and detection system for remote ocean regions.

To be built by NCAR and the University of Wisconsin, the system will use data from a variety of NASA Earth-orbiting satellites to give pilots "on select transoceanic routes" real-time turbulence updates. It will provide pilots and ground-based controllers with text-based maps and graphical displays "showing regions of likely turbulence and storms". Initial flight tests are set for next year.

The spectre of severe weather on such remote routes is a key element in the investigation of the crash of Air France Flight 447, the Airbus A330-200 that went down in the South Atlantic off the coast of Brazil on 1 June.

Separately, the US Federal Aviation Administration and the Colorado-based National Centre for Atmospheric Research (NCAR) are developing eddy dissipation rate (EDR) measurement algorithms that use existing weather radar systems to determine vertical wind currents, providing an aircraft-independent objective measurement of turbulence that is automatically downlinked to airline operations centres.

The FAA says EDR-based systems are a Next Generation Air Transportation System-required parameter.

Whereas voice-based pilot reports are relatively infrequent and subjective, the more frequent automated EDR data reports provide a definitive measurement of the level of turbulence that a particular aircraft is experiencing, a key element for maintenance planning and an input that the FAA says has been shown to improve weather forecasts.

In an effort to bring down the cost of FAA-funded prototype systems now being fielded by Delta Air Lines on its Boeing next Generation 737 fleet and soon by Southwest Airlines, the FAA is conducting market research to identify manufacturers able to build EDR-based systems that compare favourably with the performance of existing prototype units, but can be built and deployed at lower cost. Responses to the survey are due by 6 August.