Steve 76,
That heavy snow test is no joke, I did them in the S-76A back in 82 or so, and it was a really fun test. Everywhere we landed, the airport closed down, school was out and we went to work, flying continuous ILS approaches to accumulate time under the heaviest snow conditions (W100ovc 1/4 S,BS), daring the engines to quit.
To help pass the test we developed the snow blankets by using the snow making machines at Powder Ridge in CT, working out of the tennis courts at the bottom of the main slope. The skiiers were surprised to see a helicopter covered in frozen slush, running its rotors at the bottom of the lift, throwing chunks of ice the size of hot dogs around the courts.
Nick