Did Airbus not do the falling and blowing snow certification for the IBF?
"snow" is a fairly broad generalisation. There are vastly different types.
I spent some time talking to I think it was the guys from Dart at AHI in Grand Prairie TX who had just completed FAA certification on the filter for the AS350B3.
They had been up in Canada and it is actually pretty involved and difficult.
Maybe AHD used the "
wrong type of snow"