Mobile phones on flight line

[Peter Siggins]

Hi just a question on mobile phones switched on and carried in pockets whilst flying models,is there any problem with phones interfering with the 2.4 signal ?

Cheers

Pete

[David Berry]

We leave our phones in the pits, you can't answer them while you are flying anyway.
I was lead to believe there is a miniscule risk of the Tx's memory being affected, so I keep my phone away from them whenever the Tx is on.

[Rob Buckley]

Radio-wise the phone part of a mobile phone is not on 2.4GHz, but the WiFi & Bluetooth are.

I've also heard the tales of mobile phones doing strange things to computer transmitter memories, but it was a looooong time ago, and I've never actually seen or experienced it in practice, and not heard any rumours for quite a few years.

I'm more of the opinion that the safety benefit of having a phone in my pocket on the off chance I badly slice myself with a rotating knife outweighs any potential theoretical interference risk, and always fly with a phone on and in my pocket.

[Dave Collis 2296]

The Canadian MAAC (model aeronautic association of Canada) sent out an advisory a couple of years ago regarding the proximity of cell (mobile) phones in the pits and on the flightline.

I have witnessed a case where the flyer, I was standing next to him, had his phone ring and his plane started to fly erratically, the phone stopped ringing and the plane was fine after that.(on 2.4)

Now all phones are to be off and left in your car.

[Dave Hayfield]

I operated TX control at many shows for many years a while ago when we were still using 35 Meg but with a few 'new fangled' 2.4 Tx on the flight line. In all of those years only came across one incident of a mobile phone wiping the memory from a Tx which was operating on 2.4, well it may have been the phone or it may have been something wrong with the Tx, difficult to prove.........Discuss.

[Peter Siggins]

Thanks for replies - I know nothing is conclusive,but it does seem as if there is something.

What prompted the question was one of our members,who is very careful with his flight prepping,lost a model which has had many trouble free flights.
It seemed like the signal just blanked out .When tested after the crash,which wrote the model off,everything worked perfectly and range tested much further than would normally be tried.
The only conclusion was that his phone,in his pocket switched on,did an update around the same time as the ‘lock out’.,which is similar to one of the replies.
Just hope the new idea of leaving the phones on our tables behind the flight line prevents further issues.
Trying to tie down causes for unexplained crashes is a pretty hopeless task,as most incidents can be put down to pilot error - not this one however.

Cheers

Pete

[Rob Buckley]

In that case it should be fairly straightforward to replicate if it was the phone. Do a range test and ring the phone / download something onto the phone and the radio should stop working.

If it can't be replicated, it probably wasn't the phone.

[Peter Siggins]

Thanks Rob worth trying ,although Sod’s law nothing will happen .

When we get chance to give it a go I’ll let you know,at the moment so much rain and cold weather our field is a bit soggy.

Pete

[Vincent Raia]

A lot of these unexplained incidences can be caused by a flight battery, Nicads are notorious for suddenly playing up, then people couldn't find anything wrong with them, usually under load.

[Bob Thompson1894]

We were warned not to leave a mobile close to a transmitter, as the 'logging on' as it came past a cell could alter eprom memory. I heard of instances, but never saw proof. Still wise not to keep them together though. The whole mobile on the flight line thing seems to have lapsed, with people even using them while flying...
The other thing about mobiles is the risk at garages etc. I got shouted at by an irate shop assistant for answering mine outside the shop, thirty yards from the pumps! There has NEVER been an instance of a fire caused by a mobile phone at a garage. 90% of petrol pump fires are caused by static electricity, like the shock you some times get when you step out of the car and touch bare metal.

[Timothy Huff]

As a flying instructor, years ago, I had a Singaporean student who would constantly bring his bloody 'phone with him on flights, and as these interrogate by line of sight - usually 2-3 towers, of course it went nuts when at altitude and could now choose from umpteen towers it could now "see". The interrogating signal could be plainly be heard inducing sound in our RT headphones.

I'm by no means expert on these things - I don't even use a mobile - but my understanding is that the interrogating signal is rather more powerful than the usual signal strength once the 'phone has "decided" which tower it is going to deal with. So you might be looking at a situation where interference is only intermittent and for very short periods, unless a tower goes u/s for some reason, at which point all the nearby phone's will re-interrogate the local towers - all at once!

The fuel-pump risk is theoretical, but I think banning their use whilst people are on the forecourt is nevertheless very sensible. You don't now use your mobile when driving, as it is demonstrably a measurable distraction. So why use it when dispensing highly inflammable liquids? Especially if you might drop the bugger - and it's powerful battery - onto the concrete hardstanding where a consequent short could be cause life to become very exciting - and brief - very quickly... if you disagree with the preceding statement, try balancing a bucket of petrol on your head whilst throwing nicads onto the concrete floor and see whether bystanders move away briskly … or not.

I suggest that the precautionary principle should apply here. If it emits radio waves, or strong magnetic fields, and isn't expressly designed to be used with RC aircraft electronics, then I would say it's unwise to have it hard by the models or in the area of the transmitters. It's just one less potential source of interference/distraction/ignition when one is swinging a prop, fuelling-up or flying your pride-and-joy.

My Singaporean student was shewn a bucket of water by the crew-hut, and it was made (in humour) very clear what the fate of his telephone would be if it left the ground again! (this in the days before 'aircraft mode' on mobiles).

[Bob Thompson1894]

Some years ago we had a club fly in visit from the BBMF Spitfire. The pilot rang me on my mobile (from his mobile) to explain he was two minutes late but would be approaching from the North. I should imagine he does that to most of the places he visits, so maybe Spitfires are immune...

[Steve Mansell]

Gigaset, Medion, TechniSat, are the only makes that affect the Spitfire (they are all German manufacturers)

[Bob Thompson1894]

yes, but not that badly....lol