Here is mine:
As a kid growing up in Kenya, and being plane-mad, we had a neighbour who was a Swede and a Captain on Dakotas with East African Airways.
The "big Swede" as he was known in our family, took me for a trip on the Dak. On the 4th sector, leaving Dodoma, in Tanzania, pulling the throttles back at the top of climb caused a loud and unpleasant banging. The left engine was pronounced "kaput" and we returned to land at Dodoma.
After consultation with the EAA engineers at Dar-es-Salaam, a Twin Otter load of engineers, tools and spares was despatched to Dodoma.
On arrival, a wizened old Scot pronounced the likely cause to be a broken con-rod. He removed the cowling, and then instructed Sven to get into the cockpit, start the engine, and run it at idle.
Standing underneath the running engine he listened to it's beat carefully, cocked his head one way, then another and finally signalled for the engine to be cut.
He then pointed to the offending cylinder, which was speedily removed to show, sure enough, the broken con-rod.
A glorious harmony of man and machine you could say. Still impresses me to think of it nearly 40 years later.
BSD.