I have used an Alpha for a while on a Squirrel until I switched to another Squirrel and suddenly it didn't work. The avionic guys don't know what the problem is. We have the same problem with all the Alpha's. I had switch to a Gallet (Aus) helmet which I must say is very comfortable. It's not as hot as the Alpha because we operate in temp up to 45C. I'm very impressed with the Gallet. Luckily the work pays for our helmets
