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Posted by on Jul 16, 2013 in Blog, Video

Chalk Pit Wind Chasing

A Whiter shade of shale…

Sorry about that. But what I lack in punning excellence I hopefully make up for in brave(ish) piloting, and today I am being tested to the max by everything nature and engineering have to throw at me, as I manfully take to the skies over Portsdown Chalk Pits, just over a bit from Portsmouth.

Cliffs: Check, Pylons: check, Wind - too much of that if anything.

Cliffs: Check, Pylons: check, Wind – too much of that if anything.

I’ve got my friend Tudor with me, who is both spotting (and heroically keeping the dogs away) and floating about on the ground with my GoPro 2 and his own muchly superior Nex 5, the footage from which hasn’t quite made it over to me in time for this video, but will be very interesting to see as I’m planning to mount one of those on my flyer at some point, and it’ll be nice to see the quality first-hand before I do.

Location, Location

Ray, the plane guy I met up at Butser last week had kindly sent me the link to this place, and cliffs, and chalk quarries being 2 of my favourite things, I hot-footed it down there at the first opportunity I got to fly, with rather too brief a glance at the satellite mapping, and arrived to be pleasantly surprised by the proximity and loveliness of the cliffs, but suitably horrified by the proximity of big, hazardous things I didn’t know would be there. What are they then ?

Hazard Warning

Cliff-diving. Without any actual diving.

Cliff-diving. Without any actual diving.

This is a level 4 fly-site, possibly bumped up to L5 because of all that wind. Once again the BBC had advertised the wind as being ‘4 mph with some coastal breezes’. Pfft.

Well ‘coastal breezes’ wasn’t the half of it. Coastal bloody hurricanes more like. The updraft coming off those cliffs was immense, and descents were extremely difficult to perform and control. But control I must retain, for if not, I risk flying into the cliffs themselves, or worse still, any of the surrounding electricity pylons, or the manifold cables leading to them.

The latter seem particularly capricious, as they are almost invisible on goggles or a screen until you are right on them, and are equally difficult to see with the naked eye against any background except blue sky. I avoided the problem by confining by flyings so that I didn’t go within 80 ft of them – I used them as markers past and over which I would not fly.

Not only was the wind incessantly rocking me, but it was also draining my battery power <3 times faster than usual as my poor motors revved and re-revved to try and maintain balance and control. I was expecting this to some degree, but not as much as I got, because I had an almost-crash when a battery pack crapped-out on me as I was trying to descend and track home after 3 mins 30 of flight. I’ve had 8 mins out of that on calm days.

Electricity Pylons

Can we fly near them ? Yes you can, or at least yes I could yesterday. Interesting noises on the ground though, ominously radiating from the various epic voltages around my launch site…

Black Hawk Down

And down we came, far too quickly for my liking, but thanks to my foam skids, the long grass, and the various suspension mounts on my aircraft, incredibly it didn’t flip, and didn’t break anything. I did one additional flight once I had given it a visual inspection.

The cause turned out to be, as suspected, a drained and overheated pack. It was a Turnigy 5000 25-35C pack that had done maybe 120 flights ? Anyway, it was hot and puffed when I got it out, and one cel was drastically lower than all the others, so I suspect that flight was this pack’s last – I won’t risk using it again. It was labelled and set aside for filmed destruction later, so we can all see what a LiPo fire looks like.

Enemies

Home to angry birds, apparently.

Home to angry birds, apparently.

Even when the batteries were fine (all other flights today), there was no shortage of ‘enemies’ to deal with. We’ve talked about the wind, which was immense. There were dogs on the ground, as there always are, none of them on leads (of course), but the main harassment I was getting was from a bird, who saw me take off and fly over the cliffs, went to get his mates, who then proceeded to flock at me for a good 3 minutes of several flights.

Knowing that birds usually only do this when they are protecting young, I guessed I had flown a wee bit close to nests they must have on the cliff edges / sides. It is that time of year isn’t it ? I tried not to go so near after that. They didn’t actually contact my craft at all – just swooped close by it from a variety of angles and heights. An interesting, if slightly terrifying experience for any pilot, RC or otherwise, I’m sure…

And just as well. If just one of those delicate little wings had touched just one of my 11″ spinning blades, we’re both falling out of the sky, and nobody’s a winner.

What’s that coming over the hill ?

And then there’s the Navy, up on the hill there. I should have noted this fly site’s proximity to the Naval base, but I didn’t – it seemed much further away on the map. As soon as I got above the cliff tops I could see on my field monitor that I was much closer to it than I would ordinarily fly to any sort of military establishment. At worst, I could be viewed as a threat, and shot out of the sky, or my TX control could be jammed, or they could send people out to find me. I want none of these things, so swiftly altered my flight course to minimise the amount of time I spent up that end of the field.

And that's the closest I'll be getting to that...

And that’s the closest I’ll be getting to that…

In all seriousness I doubt it’s a big problem for them. The buildings are all clearly visible on maps and from the road that supplies them, and if they really didn’t want people just ‘seeing the buildings’, from some distance, they wouldn’t have allowed a public footpath close to the cliff tops, which they have.

Retention Ratios

Today I found the limits of what my Aeroxcraft Brushless gimbal can do. Normally, it can make even quite harsh winds seem invisible, but this was entirely the wrong type of wind.

Short, sharp powerful blustery gusting blasts were all that was on offer in the skies today. As soon I got above 50 ft, I found myself just in a maelstrom of multiple layers, varying currents and drags.

My poor flyer was rocking about like it might flip at any moment, but at least Naza M V2 upgrade firmware kept levelling it. But what the Aeroxcraft consistently couldn’t rescue was the shaking to the camera caused by such extreme wind acting on the various rubber and silicone mounting systems that perfectly eradicate jello, but are free to wobble about in blustery upwinds like this.

I’m fairly sure the only solution is ‘don’t fly in such stupid wind’. Having said that, 60 FPS slow-downs and some relatively wind-concurrent moments allowed me to come up with about 15 minutes of half decent footage from half an hour of flying, so about 50% footage / airtime. Not as good as it has been, but understandable in the circumstances.

Never mind, we can always get photos whatever the wind is doing, so let’s have a gallery, in which you click for full view, as is the tradition… we’re suffering slightly from what the GoPro 3 sees in harsh sunlight, but generally it’s doing a great job in equally difficult, contrasty lighting conditions.

See you next time, people…

JW