Just a short bit ago, I heard Syscom (on 44.74) key alert tones and then dispatch Trooper 3 for a medevac in Mt. Airy. No further immediate chatter, so I assume this was a tone out for the hanger and not just a redirection of the bird already in the air. Curious. I don't believe I've ever heard this done before. To my knowledge, aviation sections have always been alerted via landline calls or the digital pagers worn by the crew. It certainly makes sense to be able to tone out the hangers, in the event that commercial lines/towers are not functioning.