I think they are different, but I could be wrong. I tried finding some info online, no luck. HS125 types for the Hawker, are the same, not including the 1000, again not sure. All you need is differences training, but the AC couldn't be more different. Weights, limitations, engines, avionics, apu's, on and on. Flight Options crews set a record for submitting NASA forms with Honeywell and Collins AC.