Recently I've been flying on an LX A330-200 and I was sitting in row 18. I assume that's more or less above the main landing hear.
Fact is, while taxiing, and even while just waiting on the taxiway or runway standing still, I heard strange metal noises coming from below. The best way to describe it is someone banging iron rods one against the other.
When lined up on the runway, the noise stopped for about a minute, while waiting for take-off clearance. Then, about 10 seconds before the engines started spooling up, the noise started again.
I was wondering what exactly produces these noises. Can anyone help?