From memory I think we swapped over to the 56Ps in 2000. The reason was it's a better helmet. The lining of the helmet is molded to your head for a better fit and it has better hearing protection than the Alpha. Back in the early 90s we were all wearing the Alpha without EARS (hearing plugs). The Army did some tests then mandated all crews had to wear hearing plugs with the Alphas to reduce the noise exposure to crews.
