Night landings by quasi HEMS police units is done under the auspices of "casevac". Thats the way they get away with it. It's a hangover from the police only ops procedures. Though still available, I suspect it's going to be removed come the next revamp of the POM1 as JAR Ops continues its relentless takeover!
Secondly, preliminary reports from a preview of the latest Air Ambulance report undertaken by Sheffield Uni, indicate that the increase in Air ambulances nationally, might be the right philosophy.
