In the time of one of the desert storm wars I lived in Basingstoke, near to RAF Odiham where the chinooks were based. One day a whole squadron of them came over, low and the ground shook and I 'had to breathe in time to the thumping'. No, not really but you know what I mean. One day I was cycling home from work and I decided to take a public footpath that ran close to, and above the base. I stood mesmerised while I watched a Chinook do horseshoes. Like a child on a swing. It would fly vertically upwards, i.e. with the blades one vertically above the other, stall, fall back down, do a U at the bottom and then fly backwards upwards vertically. Doing wateveryoucallits like the Pirate Ship ride at a fairground. I watched and watched and it kept on and on doing it till eventually I got bored and left. I imagine the cleaners had a long job in the cockpit after it landed.
I remember in 1970something when one of them was carrying a number of cabinet ministers over to Ireland when it crashed into a hill. As everyone was dead it was easy to blame it on pilot error. But the magazine Computer Weekly took up the case and eventually it was proved to have been a computer fault - or programming fault.