Weather implications on commercial multi rotor operation within the UK.

[StuR]

Hi. I'm wondering if anyone could shed any light on this for me as I' am finding it difficult to get a clear idea of how much down time is to be expected when commercially operating a UAV in the UK. Given the wether of late I would guess this is a lot :crushed: I've downloaded met office data and compared the averages to the windspeed limitations of a heavy lift X8 for example. So far, I've concluded an average of 1 days flying per week (over a 48 week year). I realise this could be out either way and if anyone has any advise on this it would be greatly appreciated?
Im also aware that I have not posted on the forum very much and so, for those who are wondering… in brief my details are as follows. Im originally from Lancashire. I have a background in film and photography work that ranges from teaching young people photography and video art to filming extreme sports (such as Down hill MTB, MX, climbing and BASE jumping in Europe and the UK). I have experience in building and flying RC models and I am just starting to learn multirotor build and flying. Many thanks. Stu.

 

[Jumpy07]

Stu,

I have just done a similar exercise, I was trying to work out market value, potential share etc.. as part of the business plan etc as well...

I am in Scotland so would think my calculations would be worse than yours ... but my worse case scenario would be 60 days, possible rising to 90 days.. this assumes that the work you are doing needs wind less than 15mph... obviously the nature of the work you are undertaking will change this v the weather conditions.. ie: doing still pictures you will get away with slightly higher mean wind values than say for doing video for production.

Another factor I am running into over the winter is the low angle of light.. this results in very small windows during a good day to get some jobs done over the winter period .. even if its dry and calm.... this is especially an issue for me in valleys or in hilly areas... I spend a lot of my time looking at the Google maps feature that allows you to see light on the landscape at different times of day. So I am finding some potential jobs taking longer over the winter.. ie: several days than one day it would take in the summer.

If you are doing this as you main job then its not too bad as you can adapt to the weather... but if its a sideline or supplementary then the other issue you have is there will be some days that a good you will have other commitments etc... this will also reduce the number of working days etc..

Must admit.. more I get into this, the weather is my largest barrier to potentially making money..

 

[StuR]

Thanks Jumpy07. Sounds like we are at similar stages of business planning! Yes i'm working on a max wind speed of 15mph as i'm primarily concentrating on stills to begin with. I'd obviously assumed a shorter working day during the winter months, but I must admit I had stupidly not even considered the low angle of light. I have even encountered similar problems when filming BASE jumpers, (from my fixed position) as they track from the shaded cliff faces into open well lit (sunny) air. Im envisaging days grounded, will be taken up with post production, office tasks, social media/marketing etc, but yes the potential frequency of such days is still a concern.

 

[ZAxis]

Weather is indeed the biggest factor to consider for work in the UK. The real problem is its unpredictability, you cannot make a reasonable decision to go for a job more than 24hrs before the due date. You need clients who are flexible and understanding. They will rarely need to cancel a shoot for a ground base cameraman in conditions that will prevent aerial work and you need to have them appreciate that. On a longer shoot there may be days when you can't fly but the ground crew can film, so do you charge for non flying time and at what rate? A weather based cancellation on your part can have cascading effects on a production, availability of talent and equipment, etc could be compromised.
Plenty to think and worry about!

andy

 

[StuR]

Thanks ZAxis. Yep plenty to consider. I know from undertaking commercial work that delays of any kind during a shoot don't go down well, everything needed yesterday!! I suppose, like always, it's about building a good relationship with the client and ensuring they have a clear understanding of our operational restrictions. Do you primarily undertake film work?

 

[CrashMaster]

My quad can fly at around 35-40 mph in manual mode or about 30-35mph in GPS mode - that is air speed not ground speed. You would then expect winds of upto 25-30mph would be OK but the take-off means that the second you lift off the machine is going from 0 to 25-30mph in less than 1/4 second. That is very hairy with it pitching violently into the wind to try and maintain position and gain height so as not to crash immediately. The next problem is that with winds like that the machine is bucking and moving so much, getting the right shot is more luck than skill. Although skill can help a lot. Next is that the flight time will be cut down by up-to 1/3rd because the machine is constantly flying flat out to stay still so the lipos are drained very quickly compared with a nice sedate hover in a 2mph breeze. The last issue is landing...... To maintain position in a 25-30mph wind the machine is pitched over, into wind, by upto 30 degrees. This simply means that the skids are more likely to dig into the ground and topple the machine over or a gust will hit just as you are touching down. This means that the likely hood of prop damage is very high and possibly more serious damage should it all go really wrong and you plant the machine in the mud. But the customer still wants their shots..... and yesterday.

I purposely wouldn't recommend flying in any more than 15-20mph winds or if I really have to, make sure I have somewhere in the lea of the wind to land and take off and land using manual only. The wind can mess with the on-board altimeter too.

That leaves someone in the Orkney isles about 7 days a year to fly or someone in Kent 90 days a year to fly.

 

[StuR]

Thanks CrashMaster for the detailed reply. Very informative. I'm working on the assumption that anything higher than 15mph wind will ground the MR for the safety of the rig and persons/property. Sounds a very risky manoeuvre to get airborne in strong winds from your description. I'm surprised you didn't refuse to fly in such conditions and a client that expects you to either needs better educating or avoiding altogether.

 

[CrashMaster]

I haven't got my BNUC-s yet and am working on my ops manual to get it. However, have flown IC helis since the mid 1980s so can confirm, to my own cost, that wind can be a killer for small machines. Although variable pitch machines are more adaptive and are not constantly speeding up and slowing motors to cope: they use instant variations by pitch to increase or decrease lift and the kinetic energy in the blades. Flybarless VP is even better with reaction times to collective input much quicker. A Variable pitch Heli is able to fly better in winds as a result. Also weight helps too: the heavier the machine means less or at least slowed down effect on the machine. Fixed pitch would be suicidal and that is exactly what a multirotor is but with 3,4,6 or eight fixed pitch props fighting to keep stability.

 

[StuR]

Cheers CrashMaster. I have seen a Heli used to capture film footage, but I'm not sure of the specific type as it was being piloted by a Spanish chap. But it was very windy and he seemed to be holding it very steady, despite the conditions. Do you know how the larger coaxial rigs fair, such as the Droidworx Skyjib X4, given their weight and power?

 

[Jumpy07]

My H950 CarbonCore with A2 (7kg) flies well in constant wind.. it just leans into the wind.. and the Zenmuse copes well

Its the gusts that will cause issues.. sudden and constant gust will render any video un-usable .. no mater how good your gimbal is

Typically coaxial frames do better in the wind... I prefer to fly my Y6 when its windy for that reason.. ..

My friend has a Droidworx X8 and it is very good in the wind.. I also think the gimbal being in the centre under the frame with retracts helps.. as it prevents any pendulum effect that you get on other frames that have the gimbals out front and lipos out back.

 

[CrashMaster]

I think that all y3 and y6 configurations are better suited for wind. They can certainly fly faster which makes them more suitable to flying in winds. Also the heavier machines will inherently be more stable in heavy winds due to greater inertia needed to knock them off course compared to lighter machines. That also makes them less responsive to rapid manoeuvres. However for AP work you really don't need or want a sports flying set-up by the very nature of what you want to achieve.
As for the difference of coaxial machines being better suited to wind I can only guess that the two motors cancelling out their own counter and clockwise torque means that more effort is put into lift and having two motors giving lift at each point must mean that the speed additional lift is delivered is increased so making the responses to wind buffeting and gusting quicker delivering a more stable flight so more stable camera platform.

Jumpy07 what you say about the centre mounted camera is very true. My system is an XAircraft x650 Pro and has, as you said, camera mounted forward and batteries counter balancing at the rear. The rail mounting system used by many manufacturers is very convenient and weight saving but with most things pluses are countered with a loss somewhere else.

I tried to link to another RC Forum (http://www.rcgroups.com) where someone was building a racing Y3 and had speeds upto 80mph but can't find it anywhere.
I did find Alishanmao flying a Seeker 450 at 101kph:-

Bearing in mind he has been into 3D Heli flying for years and is excellent and also runs his own company http://onlyflyingmachines.com/ i believe him when he says 101kph.