And it was likely the only time you would hear it. When you hear the PTU, it is extremely rare, usually after a right engine failure.
Other than thinking an APU (a jet engine, with no grinding parts) was the noise that a PTU (which is simply a hydraulic pressure transfer mechanism) could make - your only error was thinking that the noise you heard was indicative of poor design and manufacturing. Your bias against Airbus (presumably in favor of Boeing) indicates a lack of knowledge or critical thinking.
I love to buy American. But I also recognize that an American company like Boeing, is not really buying American simply because the headquarters is in American (Chicago may not actually be America though).
Don’t be biased against quality simply because you are a proud American.
On another thread I tried (unsuccessfully) to find out why videos/photos of the crash site seem to show no signs of charring/burning. I find this odd?
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!