Have only tried on the ground so far, engine running, but it seems like a nice helmet. A nice upgrade from my UL100. Even though that helmet was an XL size, that one needed a bit of DIY 'adjustment' to the polystyrene foam on a patch area on my forehead to remove what was painful pressure, but this new UL303 certainly fits my head better. Perhaps the inner dimensions have changed a little? The earcups are comfy, but I note they don't slide down on their guide wires quite as far as my old UL100 helmet did, but at their limit they do cover my ears nicely. I look forward to eventually flying with this helmet. I'm pretty confident it will perform as well in the air as it does on the ground. The audio sounds good, and clear, and the report back from a 'radio check' showed no issues at all. All provided in a nice quality soft sack with drawstring, and a fleecy neck ruff for those colder flights.