GPS spoofing in Iraq airspace

[Rocket3837]

Last week, over 12 reports submitted concerning GPS spoofing in Iraqi airspace and close to Iran airspace leading to total loss of nav capability of planes. This included the hacking of the IRSs as well...
how come the IRSs get affected by such GPS hacking as it is a stand alone equipment?
​​​​​​it is serious and alarming events as it happened in hostile airspaces (Iraq + Iran) and could lead to military reaction....

[Fursty Ferret]

Having enquired with someone who knows a lot more about GPS spoofing than me the conclusion was that to do this kind of spoofing requires fairly specialist kit that may have fallen off the back of a Russian lorry.

Basically you need to identify the aircraft and deliberately target it with a very strong fake GPS broadcast which computes a position offset from where you want the aircraft to fly, but also plausible enough to be accepted by the FMS as valid.

[Rocket3837]

FF,
the reports talk about IRSs become unusable, VOR/DME sensor inputs fail, the aircraft UTC clock fails, and the crew have been forced to request vectors from ATC to navigate,”. The report says this kind of spoofing has not been seen before.

[hans brinker]

FF,
the reports talk about IRSs become unusable, VOR/DME sensor inputs fail, the aircraft UTC clock fails, and the crew have been forced to request vectors from ATC to navigate,”. The report says this kind of spoofing has not been seen before.

GPS/VOR/DME are radio signals, so can be jammed/spoofed. The UTC clock can be set to automatically update to GPS time (depending on aircraft type), which can be spoofed. Depending on aircraft type, GPS/VOR/DME could have a higher priority for position calculation than the IRS, so if GPS/VOR/DME signals are successfully jammed/spoofed, position could become unknown, and vectors from ATC might be required. There is AFAIK no way to jam/spoof the speed of light, so it is IMHO not possible to render the IRS unusable from outside the aircraft. Depending on aircraft type, switching off all radio navigation input, including GPS, might have resolved the navigation issues. Link to report appreciated.

[Rocket3837]

Appreciate yr inputs....
https://www.flyingmag.com/gps-spoofing-raises-alarms/

[MechEngr]

How long until the gyro drift becomes too much? Does the IRS get corrections from the GPS?

[Fursty Ferret]

FF,
the reports talk about IRSs become unusable, VOR/DME sensor inputs fail, the aircraft UTC clock fails, and the crew have been forced to request vectors from ATC to navigate,”. The report says this kind of spoofing has not been seen before.

The inertial reference for attitude is unaffected. Position data is corrupted or incomputable.

The is because the FMC is unable to verify its position. It sees a conflict between inertial, GPS, and VOR/DME and cannot reconcile between them because both GPS ***and*** VOR is unreliable in Northern Iraq.

[hans brinker]

How long until the gyro drift becomes too much? Does the IRS get corrections from the GPS?

Well, it was used to cross oceans before the GPS era. I think most FMSs use the GPS/VOR/DME position info as an update/bias to the IRS position data, so if the radio info isn't available anymore the FMS has the most reliable position to continue dead reckoning from the IRS.

[MechEngr]

Before GPS the Russians blew an ocean crossing plane out of the sky prompting the release to public use of the military navigation system.

Given the over-precision of following GPS (the head-on collision over South America - GOL Boeing 737 and an Embraer Legacy 600) and dependence there is a smaller error bounds allowed than before.

That brings up the question - can TCAS be jammed or spoofed?

[jolihokistix]

Well, no-one has mentioned this here yet, but US bases in Iraq have been hit by fairly accurate missile attacks from Iran over that same border. Would it not be natural to want to deploy an up-to-date multi-dimensional spoof barrier there?
Just a theory, mind you.

[Less Hair]

Existing thread on this:
https://www.pprune.org/rumours-news/654984-airway-um688-iraq-has-been-started-elsewhere.html