San Diego

Plans to develop a system for detecting air turbulence are gearing up again, three years after a lawsuit brought by an airline pilot halted the original research.

Unexpected turbulence causes hundreds of injuries every year on commercial flights and has resulted in the deaths of at least three people. But atmospheric physicists have had limited success in understanding the phenomenon, and it is difficult to predict precisely when and where turbulence will occur.

In 1995, Larry Cornman, a physicist at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, published details of software that can detect and quantify turbulence, and which gathers data on the conditions that create it. The software monitors the plane's vertical acceleration along with a dozen other factors such as altitude, speed and air temperature. A measure of the turbulence can then be transmitted to other aircraft approaching the same area (L. B. Cornman, C. S. Morse & G. Cunning, J. Aircraft 32, 171–177; 1995).

A new version of Cornman's software is now being installed in aircraft. But the researchers involved say that a large portion of the US commercial fleet could already have been equipped with the system were it not for a lawsuit that halted the project in 1999.

The software had by then been installed in about 80 Boeing 737s as part of a collaboration between NCAR researchers, United Airlines and aerospace company AlliedSignal (now merged with Honeywell, an engineering firm in Morristown, New Jersey). But the project stalled when Gary Bush, a pilot with Delta Airlines, filed a federal lawsuit in Fort Worth, Texas, alleging that the system infringed a patent he received in 1996 for a turbulence-detection system. Funding from the US Federal Aviation Administration (FAA) was withdrawn while the lawsuit was contested.

But NCAR researchers claim that the patent contains only vague details of a detection system and should not have been issued because of Cornman's earlier publication. Bush got no compensation when the case was settled last year, and the agreement left the NCAR free to use the data collected by its system for non-profit research.

Bush says that he never expected the FAA to stop funding the research, or the airlines to stop installing the software system, and that this is one of the reasons he settled the case.

The scientists who developed the software say that the case taught them an important lesson: don't rely on the published record of research to ensure free and unlimited access to a new technology. Securing a patent to ensure wide accessibility may be a better course of action, they say.