Commercial Flights Are Experiencing ‘Unthinkable’ GPS Attacks and Nobody Knows What to Do::New “spoofing” attacks resulting in total navigation failure have been occurring above the Middle East for months, which is “highly significant” for airline safety.
That just means you can’t use autoland in low visibility conditions. Modern IRUs (inertial reference unit) are highly accurate laser gyros that can use GPS for correction, but will throw out the data if it doesn’t make sense. Navigation won’t be affected much, and autoland (if used) will still rely on VHF guidance.
But the article mentioned that “the spoofing corrupts the Inertial Reference System”. How?
If it’s a smaller plane (such as a CRJ / ERJ) with only one IRU, it will not be able to determine if GPS is valid or not, so the drift correction gets spoiled.
Large commercial aircraft are using 3 IRUs, with newer aircraft using ADIRUs. If GPS does not agree with the three IRUs, the GPS data is thrown out. If the GPS is within tolerance, correction is applied. You could build up very small errors over a long distance, but you should still be pretty close to the airfield when you get there.
Ignore my ignorance. Are you saying the aircrafts track where they are going by calculating their position from gyroscope data? And this is more precise than GPS?
That’s like using the accelaration sensors in your phone to navigate. Or sailing with compass and nautical maps.
Possible. Tech isn’t even that novel. But still impressive.
Yes. Most of commercial navigation systems rely on the IRUs as a primary source of position data, and they’ll usually have 3 of them. VHF is used by the crew to confirm that the aircraft is on track by referencing VOR stations, though these are slowly being phased out due to GPS.
That being said, a single traditional IRU can have up to 2km of drift over a 2 hr flight (at which point it’s removed from service and replaced). When used in combination with two other IRUs, the error is dramatically reduced. Traditional IRUs are gyroscopically mechanical in nature and do not talk to GPS.
Now, that being said, the new standard is called an ADIRU (ADvanced IRU), which ties in with GPS and features laser gyros. They’re extremely accurate and have essentially zero drift, plus multiple redundant components within each unit.
How do IRUs work do to give you location?
https://en.m.wikipedia.org/wiki/Dead_reckoning