It's fairly unlikely that you'll ever worry about snakes on a plane, but what if one of your co-passengers has SARS, or worse, is about to release some anthrax spores? US researchers are working to find the best way to detect such hazards.

Nearly two billion people travel on commercial airliners each year, and it is important to detect such problems as quickly as possible by installing sensors. However, the number of sensors that can be installed is limited by cost, size and weight. The question then remains: Where do you put the sensors to get the fastest response?

Instead of using a full size replica of an airliner cabin, Sagnik Mazumdar and Qingyan Chen from Purdue University, West Lafayette, US, created a virtual cabin and used computational fluid dynamics to study the effects of the seating arrangement and the number of occupants on the optimum position for these sensors.

'In 2003, one passenger passed on SARS to more than a dozen others,' said Mazumdar. 'It's this kind of tragedy that we hope to help avoid.'

Their research is one part of a larger coordinated research effort called ACER (airliner cabin environment research). 'It is essential to deploy sensors that can provide instantaneous information. Research into new sensors that can provide instantaneous results, particularly for biological agents, is another important area for research,' said Mazumdar.

Stephen Davey