Yesterday while driving on the NJ Turnpike, I saw a heavy aircraft(looked like a 767 from distance, not sure however) that was initially aligned just fine on the ILS for 22L(at least from the looks of it). The strange thing though was that during short final it abruptly started banking hard to the left, and then after maybe 5 seconds a hard turn to the right. It looked pretty scary, like the pilot lost control over the aircraft for a moment. However, during the last part of the approach, it got lined up again with the localizer. My question to you(hopefully it's not a too stupid question) is, what couldve been the reason for this? Could the aircraft have been on the final approach course for 22R at first(which to me might seem odd at KEWR), when the controller then maybe instructed the aircraft to enter final for 22L? Or could it have been that the aircraft was actually on the ILS for 22L, and then the controller gave some instructions to the pilot to deviate from the loc? And is this even possible during the last phase of the approach for the atc to give that kind of instructions?
And what is the distance limit for an aircraft on final to enter another runway?
Alex