found water in the carburetor and determined the failure was caused by carb icing
What I was referring to was that it is impossible for ice to be formed inside the carburettor. Unless it is a new model that may also dispense the ice for in flight drinks.
Water inside the carburettor comes from dirty fuel and overloaded filters and almost always causes the engine to stop because the blessed stuff will not vapourise the way fuel does when the airflow thru the venturi is trying to suck it out of the carby bowl to mix with air and form a combustable mixture. If it does get sucked out of course it would destroy the usual ratio of the mixture of fuel to air that is necesssary for combustion.
The term Carby ice on the other hand refers to and is caused by too much water vapour in the atmosphere at the prevailing temperature when it is being drawn thru the venturi where the fuel air mixing takes place, ice will build up and restrict the flow of air and the engine will usually splutter first then can quite quickly stop.
Helicopter engines will become silent, and an auto is required, especially if the machine is at a low level. Usually an aeroplane engine can easily be restarted because the propellor should be windmilling and there is often a much slower descent rate in engine off mode.
I suggest the engineer may have been having a serious lend of the pilot concerned, carby ice from water in the carburettor, indeed! Made my day.
cheers tet