halocline
Contributor
Though the diaphragms aren't available, you'll probably never need one. The only real drawback to the Air 1 is that it is a bit of a wet breather when you're fully inverted, for example, looking into a hole, or if you have a very strong current running from either side.
Actually I've had two torn diaphragms; one came on an air 1 that I had bought for the diaphragm (and other parts) and one that I suspect had a very small tear that I made quite a bit worse while fiddling with the clip. To me it's much easier working with the pilot case than the air 1 in terms of removing and installing the diaphragm. I can only imagine how many of those were torn by careless 'techs' in a hurry.
I also find that my air 1s breathe a little more wet than either of my converted pilots when upside down. The only thing I can think of that might be responsible for this is a better fit between diaphragm and case on the metal case pilot.