This question is being asked because of the revelation that a team of cyber experts at the Department of Homeland Security successfully hacked into the avionics of a commercial airplane parked at an airport as part of a test.

The problem is that nobody with knowledge of aviation cyber security is sure of how vulnerable airplanes are to such an attack—and some believe that the DHS test has simply added to the confusion and created needless alarm.

A Boeing spokesman told The Daily Beast: “We witnessed the test and can say unequivocally that there was no hack of the airplane’s flight control systems.”