Loads of people forget the fuel cap! It seems to me that the only thing a chain is good for is letting the fuel cap beat the crap out of the paint job.
I'm aware of R22, 206, 407, 76 drivers who are all guilty of taking off with the cap off/open. Anyway, point is:- Always do a walk around before you turn the key/ press the button.
Back on topic, I always checked the skid shoes, running landings and touch down auto's that look like running landings can wear them out pretty quickly.