I just have an issue there, personal issues I guess
When the Lycoming/continental show double the rate of icing compared to others... But the undetermined is so **** high...
If there's engine power loss, risk of carb ice is high, call it "likely carb icing" Put an actual number to it...
When I do my assessment of each accident, I read the narrative, not just the probable cause.
Remember, the investigator does not make the "probable cause" decision. He or she writes the factual report, and the board itself makes the final determination.
I've seen a number of accidents where the investigator says, "OAT was XXX, humidity was YYY, and the table shows a high probability of carburetor icing," and the Board actually states the accident was due to engine failure for undetermined causes.
When that happens, *my* database lists it as carburetor icing. I did a quick check, I've got 15 cases like this, out of about 100 cases where carb icing was a factor.
Also, keep in mind that not every builder installs carburetor heat, or installs *adequate* heat.
Ron Wanttaja