The coronavirus pandemic has grounded the airline industry. Tens of thousands of flights have been cancelled since the outbreak began, and layoff and furloughs have caused anxiety amongst airline workers. Scientists now say they know ways to stop viruses from spreading on airplanes. Unfortunately, they also say it's too late for this pandemic. Qingyan "Yan" Chen, a Purdue University engineering professor who helped lead a major FAA-funded research project on disease transmission aboard aircraft and has received research funding from Boeing, evaluates how much more prone flyers are to contracting viruses on planes and how safe masks are to preventing illness.