One thing caught my eye though. Given that VLOS and BVLOS create pages of speulation, opinion and discussion it’s intriguing to see the formulae that the CAA uses to determine whether a flight is possible within VLOs at a given distance.
Pages 28 to 31 are the ones to read - although the whole document is good for whiling away the odd ten minutes …
Sorry Ian, but ChatGPT came back with complete bullshit.
DLOSmax = 0.3 * GV
GV itself is capped at 5km so DLOS is capped at 1.5km. That’s max distance for ANY sized drone.
It’s worse.
VLOS is the lesser of ALOS and DLOS.
ALOS is the drone size limitation: ALOS = 327 * CD + 20m
CD is the characteristic dimension, the distance from rotor tip to rotor tip.
So for my Mini 4 pro I measured 38.5cm.
ALOS - 327 * 0.385 + 20 = 145.895m = 146m.
It’s worse.
146m is the max distance from you to the drone. If you fly a 120m then from pythagoras the max. horizontal distance you can fly is 83 meters.
If I’ve misunderstood or messed up the calcs please tell me.
Nah! Seems surprisingly accurate. Before I’d seen this ORS9 stuff I’d already assessed my own VLOSmax from the flights I’ve done at around 100m and have set Max Horiz Distance on my controller to 100m Albeit, with 70 year old eyes; others with younger eyes (and/or larger UAV’s) may well indeed fair better
I’m assuming this is for the drone as it comes out of the box. What about if someone adds a couple of strobes to it ? ( forget about weight at the moment) It’s far easier to see flashing lights in the sky that just the drone on its own. Seems to me the CAA are ignoring certain visual enhancing aids, such as strobes.
I’ve 2 green strobes which I may attach to my Mini 5 Pro (UK1) as the additional weight would well within limits for UK1 UAV (Open A1 900gm) and DJI’s stated MTOM for it (355gm). TOM of my Mini 5 with ‘Intelligent Plus’ battery is 300gm & with the two strobes would be 320gm.
However… Both the CAA & Police likely to consider VLOS a bit more than just being able to see the drone. There’s direction, orientation & space around it etc, etc.
If you look at the *.pdf attached to the first post you will see that this goes far beyond amateur pilots and the drone code. It is aimed a commercial operators and is a means to ensure documentation and practices are fully compliant.
Adding strobes to a 23kg drone will have little effect on the all up mass
Surely with a couple of strobes on, orientation is easier to determine ? ( depending upon the placement of the strobes )
I’d also question the “ rotor tip to rotor tip “ dimension. The rotors spin fast enough to render them almost invisible after about 20-30m away.
I agonised for quite a while before deciding to let my GVC lapse but I think I made the right call.
Trying to decipher this on the same day as I’ve watched “BankofDave” on TikTok explain that all he really needs to do before flying his helicopter from Burnley to Wales is call the airport and let them know he’s coming just confirms that the CAA has lost their collective mind where drones are concerned.
That suggests about 450’ for my Lito, and I’ve set distance at 500’ because, while I can see it at about 750’ with a strobe in twilight/cloudy conditions, I want a bit of a margin to see orientation/heading So the CAAs fivures are not far out; what is often far out, literally, is pilots’ assessment of VLOS wothin the strict CAA meaning… But the max is a pretty moveable feast anyway, and I’ve been known to not be able to see my drone at 20’range in broad daylight against some backgrounds!
Yep, you are correct and a salient point for just throwing stuff at ChatGPT and expecting a correct response. Not the first time I’ve experienced this.
I asked ChatGPT why it got it so wrong and this was the response:
Because I used the wrong model. I treated ALOS as a general eyesight/angular-resolution problem. The CAA document does not do that. It uses a specific LBA-derived test formula:
ALOS = 327 × CD + 20 m for rotorcraft/multirotors. I also underweighted the DLOS cap.
Given I told it originally to only use information from the document you can see how much it can wander - hence the caveat in my original post.
If the CAA are going to produce complex rules like this they should create a website that does the calculations, with an interactive map that contains estimated population densities, and the ability to select different types of craft, etc.
