The limiting factor isn’t the height the drone will fly to and still respond to the rc, or even flight/battery duration, for most flyers it is the restraint of the 120m agl limit and the need to keep VLOS at that distance. Going over 120m agl risks onflict with manned aircraft, nobody wants to be responsible for an A320-shaped burn mark in the landscape, never mind the possible fine or even prison time associated with even an airprox! If you are somewhere you can do it legally (which would certainly not be anywhere in the UK, EU, US, Canada, Australia, NZ, Eastern Europe, or anywhere even vaguely anywhere near an active war zone) and there is no conflicting traffic (bear in mind that it is the traffic that decides if it is conflicting, not you), fill yer boots, but for most of us most of the time it is illegal, dangerous, and the chances of being brought to book (or even shot down in some places) are high!
It is a little different to flying beyond VLOS range within the 120m height limit, not that I would recommend doing such a thing for a second! That does not put you into conflict with other air traffic and the risk is only to your drone (particularly if you are out over water). You are much less likely to be reported or detected on radar/similar equipment, and I would go so far as to suggest that, so long as you can see the airspace in the immediate vicinity of your drone, you are probably not going to seriously bother anyone at up to a mile or even two out from your home point. But a mile or two upwards, that’s a different story! You’ll come up on all sorts of radars, and upset all sorts of traffic!
Let us say that, for example, and theoretically of course, I wanted to fly around an off-shore island which would need me to go about a 2km out from my Home Point to get the footage I want at a height of about 100m. It’s a risk, but it’s an informed risk: I’m fairly confident in my connectivity and can see the airspace around the drone, which for the sake of argument is a Mini 4K. I can’t see the drone at that range but I know where it is, and I can barely make out any birds below the size of a gull or an oystercatcher (the main threats) at that range assuming clear conditions. Of course, I can monitor the airspace closer to the drone with the onboard camera and sensors. So, I chance it! I have hurt nobody, but I have knowingly broken the rules, so I get the bus home looking a bit sheepish and ashamed of myself but with the footage. It it all goes wrong, I’m a big boy, I’ll put my hand up and take my punishment like a man.
Now, let’s compare that hypothetical scenario with a flight going up to 2km vertically, the size of a moderate Alp. I’m intruding on airspace I am not supposed to intrude on, I may well be endangering civilian or military aircraft, I am being a complete arsehole on any and every level, and deserve all I am probably going to get, which could very well be the confiscation of my drone, a hefty fine or worse, jail time if I’ve actually caused a crash, and I would deserve all of those things! The 120m agl height restriction is (rightly) more rigidly enforced than the VLOS distance restriction…
