Ever seen it snow but not accumulate? It is also possible for it to snow when the temperature is above 32.

 

Not sure what you are looking for. You want anecdotal experience, instrumentation errors, the laws of physics are what they are, for water to be frozen it requires the molecule to be below 32f. If it's not melting until it touches 33f ground or plane, so be it. My position utilizes the easily accessible manuals that the company created and the FAA approved, and as such, clearly(or not so), defines the Ground Deicing Program. Push this stuff to the limits and one might be a future training bulletin.
How many GA/91 turbine crashes this years winter season due to icing?

 

If you read the rest of the reg you quoted you'll see that 1) the reason every OM says adhering is because it's a direct quote of the FAR and 2) under paragraph c and d it clearly states the aircraft critical surfaces must be free of contaminates.

To be completely fair a very dry, cold, snow is about the least harmful of snow. I would very much worry about snow just slightly above freezing point especially if the aircraft just came in from a high altitude flight (cold soaked) and/or morning flight out and the fuel had been cooled to below freezing overnight and now the wings will refreeze the melted snow. I've seen both this winter already myself, and that will bring an airplane down. Quest lost a TBM some years ago due to the latter.

This stuff isn't so cut and dry which is why pretty much every operator prohibits you from departing with anything on the plane.

 

No one is saying you don't have to deice. The statement is that precipitation needs to be adhering to the aircraft's critical surfaces to require it.

 

We are digging way too deep. Type 1 if it's light and move on. Stop overthinking it.

 

I'm not saying I never deice. I'm saying that it is possible for there to be frozen precipitation falling and it not adhere to the aircraft. Whether it melts on contact as it does when the base of the clouds are below freezing and the ground above or if it is a trace of dry snow that spits and leaves the aircraft without contamination, it is possible.

 

Paragraph c and d of 121.629 states free of contaminates. Your example of snow at 34* could turn into a dangerous situation.

 

Which is why you conduct a contamination check prior to departure.

 

....which requires your aircraft to be "free of frost, ice or snow". Not adhering, but FREE.

 

We are making the same argument. If there is anything on the wing, it is considered as adhering. If the wing is dry, even after a brief snow during a sit or boarding, then it is not adhering.