Why Can Pilots Still Turn Off Their Transponders? There's no reason for it, and it's time for a change: Gregg Easterbrook By Evann Gastaldo, Newser Staff Posted Mar 18, 2014 12:54 PM CDT 24 comments Comments A girl writes a message for passengers aboard a missing Malaysia Airlines plane, at a shopping mall in Petaling Jaya, near Kuala Lumpur, Malaysia, Sunday, March 16, 2014. (AP Photo/Lai Seng Sin) (Newser) – We might know what happened to Malaysia Airlines Flight 370 were it not for one thing: The aircraft's transponder was somehow turned off. In the New York Times, Gregg Easterbrook notes that the 9/11 hijackers were also quick to turn the transponders off, which is what caused air traffic controllers to lose time trying to locate the planes. After that tragedy, Easterbrook "would have bet my life’s savings that the transponder, which broadcasts an aircraft’s location and identity, would be re-engineered to prevent hijackers from turning such units off," he writes. "But nothing was done." The ability to turn a transponder off "is a vestige of an earlier era," and today, there is no longer any reason for a transponder to include an off switch. "Pilots like their locations to be known—for ground assistance, and because the transponder warns other nearby planes of their course and altitude," Easterbrook writes. "Only a hijacker at the controls of an aircraft would want the transponder silent." That's why we need to institute an automatic, location-based broadcasting system that neither the flight crew nor a hijacker can shut down. Click for his full column.