Flying a Hughes 500 from a tuna boat in the Pacific. 45 miles from the boat in "not so nice weather" I had a Mr transmission chip light! nothing to do but fly back to the boat. There's no search and rescue out there!
Another Hughes 500, flying straight and level at around 400 feet over dense forest. A sudden, and very loud bang, accompanied by a strong vibration and smoke in the cockpit. I put out a mayday call on our HF radio, again, another remote location. Fortunately found clearing to put the machine into, and landed without further damage. It turned out to be a drain tube falling into the oil cooler blower fan. I really thought the helicopter was going to fall apart. That was the first time I have ever been in the air wishing I was on the ground.