About 3-4 years ago I was sitting in the first row of a Swissair A320 flying ZRH-NCE, the cockpit door was open as we were landing.......

As the rear wheels touched down, the plane jinked to the side and a computer voice started screaming PULL UP, PULL UP, PULL UP (continuously). The pilot increased power and pulled up, we circled for another 20-30 minutes and then landed. We were told later that it was wind shear-----this leads me to believe that some part of the system is in the plane as the voice came from the console.