carb ice
The report cited at the beginning of this thread stated "caused by carb ice after a descent from 2000ft to 1500ft"
I do not see how a carb venturi can be blocked with ice in a descent from 2000 to 1500. In less than a minute.
It takes time to accumulate ice, layer upon layer, then the power starts to go down.
Disclaimer: The comments here are MY opinion only, based on my experience and thoughts only.
I flew an O-320 lycoming powered Piper cherokee for years in Alaska without ever getting carb ice.
I quit using carb heat on descent. In fact the Piper PA-28-140 owners handbook states: "Carburetor heat should not be applied unless there is an indication of carburetor icing, since the use of carburetor heat causes a reduction in power which may be critical in case of a go-around. Full throttle operation with carburetor heat on is likely to cause detonation." (quoted from the Piper manual)
So how is this relavent to the R-22 you might be wondering.
The carb on the O-320 is bolted to the oil sump and therefor gets heated to some degree by conduction from the oil sump casting.
Why would the R-22 experience carb ice in one minute while the Piper with the same engine almost never does?
Maybe the engine fan on the R-22 cools the carb more than the Piper. Just a thought.
Maybe a little more heat on the carb casting would be an alternate remedy, rather than conversion to injection. Heating the carb casting(instead of the air) does not cause detonation.
So in conclusion, I do not see how a R-22 could experience carb ice in less than 10 minutes as stated, and if it did, then the carb needs to be heated continuously to prevent further problems. Application of carb heat after the fact may not help in time and it certainly is a distraction from flying in a most stressful situation just before impact. Even for a well trained pilot.
slow