Edward A. Lee of UC Berkeley's Department of Electrical Engineering and Computer Science has proposed a technological solution to the threat of aircraft being flown by hijackers into buildings: Program the avionics of aircraft to automatically engage auto-pilot to take over control and steer an aircraft away from any airspace which it is programmed not to enter.
Lee and his colleagues have an alternative. They propose modifying the avionics in aircraft so that the plane would fight any efforts by the pilot to fly into restricted airspace. So if a plane was flying with a no-fly-zone to the left, and the pilot started banking left to enter the zone, the avionics would counter by banking right. Lee's system, called "soft walls", would first gently resist the pilot, and then become increasingly forceful until it prevailed.
Of course a bug in the software could be a cause for trouble: "Auto-pilot, I need to land the plane". "Sorry Dave, I can't let you do that".
But seriously, with GPS signals feeding into the aircraft avionics a hijacker would be hard pressed to thwart the decisions of an auto-pilot system. If the flight computer which passed along the fly-by-wire signals to the control surfaces was also the same computer that ran the auto-pilot algorithms an effort to thwart it would not be trivial. If the computer or its outputs were physically reachable while in flight then one would need to either bring along a computer of one's own with some sophisticated software to take over the driving of the outputs. Another alternative would be to get between the GPS and the flight computer and replace the real GPS signals with some fake GPS signals.
A high tech attack on the flight controls could be defended against by using encryption. The use of encrypted communications within the network of computers in an aircraft could defeat most attempts to install a replacement computer. Unless the replacement computer knew the encryption keys and algorithms used by the various embedded computers the other computers would know to ignore it.
|Share |||Randall Parker, 2003 July 03 11:17 AM Dangers Tech General|