I'm not really sure if there is any point thinking (worrying) about it. One time I was in the mountains crossing West Virginia by moonlight in a 269 happily chatting to my observer when there was a god almighty cough from the engine and it started running really rough. Instant adrenaline rush & death grip. Started lowering collective waiting for it then realised we were over a forested mountain and would have been F#*ked anyway even if it had been daylight. Neither of us said another word for the next 20 miles. Landed and went straight to the pub. Turned out the exhaust manifold had cracked. Managed to keep my trousers clean though..