Hi Grasscutter, on your first point, no, the RB isn't likely to receive a plane flying at a lower height, than the one that registered the max. distance - if you get what I mean! The max. range is mainly dependent on the aircraft's height, although some seem to transmit with a stronger signal, or their antennas are more effective/efficient, than others. I certainly find that flights disappear/appear when on my detection range limits, and is very noticeable as I'm on the bog standard 5 min. delayed - still got to make up my mind whether to renew or not in December when my 2 years ar up.