uh...and don’t practice mind reading without a license.
I heard a loud grinding noise, which IS NOT TYPICAL IN ANY TAKEOFF!
I don’t care what you think it may have been.
My observations have NOTHING to do with “buy American”!!!
I also happen to have been in aerospace for 45 years, (on the space side), so get off of your “knowledge or critical thinking” meme!
45 years in aerospace and you think a grinding noise is an APU?
I think my question your observation is right on target. Google APU.