Re: Obviously not GPS jamming
I once asked about the 747's inertial guidance and the pilot said that it would drift about a mile after travelling across the Atlantic. They also had 3 inertial guidance units just to be sure. This was over 25 years ago.
Three were required because accurate navigation was a vital part of crossing an ocean. If you’re planning on landing with no more than half an hour extra fuel then it’s no good if you take a 31 minute detour thanks to wonky navigation.
Biting the hand that feeds IT
