It messes with the aircraft radio altimeter.. The altimeter measures the distance from the aircraft the ground so on final approach which starts 20 Nautical miles from the airport usually start from the end of the runway..
So if a pilot trying to land the aircraft will read its 3500 feet off the ground when in reality it’s only 500 feet off the ground so In bad weather condition like heavy fog that can be catastrophic
Sounds like that scene in Die Hard 2 when the terrorists changed the settings for the altimeter.. Causing the plane to crash.






Ok false prophet Truest