The story about the British AAC heli pilot flaming out his aircraft's engine by flying under an irrigation spray is true. I remember reading the accident report. Might have been a Gazelle though.
There
was some concern with the open intakes of the RAF Pumas suffering from a sudden ingestion of a slug of accumulated snow/slush. Falling or blown snow used to build up on the front engine moulded cowling, between the two engine intake ducts from where it could then slip off sideways and down an engine.
Pre Polyvalent Intake Protection System, (PIPS) equipped airframes were given a reduced clearance in falling or blowing snow conditions (400 metres IIRC). An interim mod before PIPS were fitted was to fit wide angle rear view mirrors, externally above and forward of each pilot's position so we could check for snow accumulation in flight. Great idea. We used to arrange them so the whole side of the airframe could also be seen. Very useful, especially to confirm for possible signs of fire or leaks etc. However, once the PIPS came along the silly sods removed the mirrors despite our mere aircrew protests, a retrograde step if ever there was one.
There was concern about heavy rain in Belize during my times there in the late 70s to mid 80s. No-one could say how much water it would take to flame out an engine. The problem came to a head following an incident where a design fault (a single diode failure) on the starter panel could cause BOTH engines to be switched off by resetting a single start switch! So we were banned from attempting an in-flight restart in the event of an engine failure. As Fareastdriver will no doubt confirm, single engine flight was "interesting" in Belize at heavy MAUW. Having said that, I never heard of an actual engine failure on an RAF's Turmo 3C4 until someone who will remain nameless ran out of fuel in Portugal. Industrial engines, very solid pieces of engineering.
