back to article Phone jammers made my model plane smash into parked lorry, fumes hobbyist

A radio-controlled aeroplane operator blamed the crash of his replica WWII model in a lorry park on 2.4GHz radio jammers. The model aircraft hit the side of a parked lorry trailer after going out of control in April 2021 at a site near the Staffordshire town of Lichfield, in the middle of England. "It was suspected by the …

  1. Will Godfrey Silver badge


    If it were a cheap drone I'd say he was lying, but these model planes are not cheap and are given lots of love and attention by their owners, so in this case, I'm inclined to believe him. Also, dodgy goings on in lorry parks is not exactly unknown.

    1. Anonymous Coward
      Anonymous Coward

      Re: Possible

      "Also, dodgy goings on in lorry parks is not exactly unknown."

      Did you mean dogging goings on.... ?

      1. Disgusted Of Tunbridge Wells Silver badge

        Re: Possible

        Calm down Stan Collymore.

    2. Jos V

      Re: Possible

      Another version is that truck drivers will park at rest-stops when they reached their time-limits for driving, turn on their GPS jammers and continue on their journey.

      Then when drop/pick up is completed, return to the same rest-stop, and turn it back on.

      I guess more nevarious use is for thwarting the low-jack systems when stealing cars though.

  2. This post has been deleted by its author

    1. Valeyard

      Re: Failsafe?


      you keep saying that word but it wasn't a drone, it was a remote-controlled plane, drones act autonomously whereas planes need to be controlled which needs the signal to not be jammed.

      1. This post has been deleted by its author

        1. Valeyard

          Re: Failsafe?

          2. In the event of a loss of control link, you cut all engines / motors whatever

          seems risky if the signal just cuts out for a few seconds at which point it's in a nose-dive, if it carries on it can be guided back when the signal re-establishes

          I dunno anything about these planes but the first option sounds like a full-spec autopilot, bearing in mind these things don't hover or do VTOL

          1. Clive Galway

            Re: Failsafe?

            >seems risky if the signal just cuts out for a few seconds at which point it's in a nose-dive, if it carries on it can be guided back when the signal re-establishes

            If it's heading away from you when you lose control link for an extended period (Say 10 seconds) then it almost certainly is not coming back.

            If it's heading towards you, then if you regain control link after it loses it, you can pull it out of the dive.

            Besides, unless you were close to stall speed anyway, it probably won't be going into an instant nose-dive.

            > I dunno anything about these planes but the first option sounds like a full-spec autopilot, bearing in mind these things don't hover or do VTOL

            You don't need hover or VTOL for this feature. All you need is gyros (So it knows what attitude it is at) and GPS (So it knows position / heading / airspeed).

            It's not exactly expensive - a flight controller and GPS that can do this will cost you from about £50 - £100, and considering this is a 1.7m model, an insignificant fraction of the cost of the model. My mate's plane which weighs <250g has this, so it's not going to be a weight issue either.

          2. Robert 22

            Re: Failsafe?

            The plane in question had a petrol engine - small engines of this sort intended for model planes do not have the ability to restart themselves.

      2. Gavin Chester

        Re: Failsafe?

        While the public tend to think of a drone as as a multi- rotor device, typical the four armed quadcopter ie what a DJI model looks like, the CAA don't make a distinction. To the CAA a Drone is any remotely piloted aircraft or unmanned aerial vehicle (RPAS or UAV).

        The fact its remotely controlled in real time (as this was) or autonomously following a preset flight plan makes no odds to the CAA definition.

      3. Anonymous Coward
        Anonymous Coward

        Re: Failsafe?

        I'm admittedly not clear on this because I have used neither R.C. nor consumer so-called "drones". Perhaps you can help? My possibly mistaken belief is this :: Consumer so-called "drones" are R.C. aircraft, but when they receive no active signal they default to neutral activity = staying at the same altitude and place to the extent they are able. This is possible because they are little helicopters.

        Therefore a crash is not inevitable if contact can be reestablished by the operator moving closer. In contrast an R.C. plane must keep moving forward to stay airborne, so once contact is lost, there is little chance of recovery.

        1. Will Godfrey Silver badge

          Re: Failsafe?

          One that a friend of mine has, will return to its starting point if it loses signal - first horizontally, then vertically. It also monitors it's distance and battery, and if it's too close to the envelope, again it will return to base.

      4. eldakka Silver badge

        Re: Failsafe?

        > drones act autonomously whereas planes need to be controlled which needs the signal to not be jammed.

        Well no. A drone is any craft that is not being operated by an onboard operator/pilot. An R.C aircraft - or boat, car - is still a drone, and considered a drone under the law.

        An autonomous drone is a sub-category of drone that isn't being operated remotely real-time. Note the use of 2 words, together, autonomous and drone, to indicate a specific sub-type of drone that is not being remotely operated and is thus autonomous.

        1. Anonymous Coward
          Anonymous Coward

          Re: Failsafe?

          But autonomous is an ambiguous word because autonomy comes in degrees and modes. Many consumer UAVs can autonomously hover when they have appropriate references such as GNSS reception and/or well-illuminated environments. Many of these have fail-safe modes which enable them to return to a home point - in various ways - without human guidance when a signal is lost. Some of these have operating modes for following objects by visual reference, and/or for flying predetermined routes without any real-time human input. On the other hand, is a waypoint flight really autonomous if a human specifies the route in advance? One might even argue that the subject aircraft was rendered autonomous by jammers and autonomously flew into the side of a truck.

          I challenge anyone to fly a quadcopter by directly manipulating four control inputs for four propellers; Normal people don't have such skill. So perhaps any quad that is flyable by a human is autonomous.

          Or maybe a UAV is not truly autonomous unless it kills its owner...

          1. eldakka Silver badge

            Re: Failsafe?

            > But autonomous is an ambiguous word because autonomy comes in degrees and modes. Many consumer UAVs can autonomously hover when they have appropriate references such as GNSS reception and/or well-illuminated environments. Many of these have fail-safe modes which enable them to return to a home point - in various ways - without human guidance when a signal is lost.

            Right, one device can support multiple modes of operation and can operate at different times in a single session in any of those modes.

            Most autonomous drones have the capability to be remotely operated, some even have the capability to be locally operated too (e.g. the various self-driving test cars still have steering wheels and other controls that a driver could then use to operate the vehicle locally).

            So when it is being locally operated, it would operate under the appropriate laws WRT that operation. e.g. appropriate operators license (e.g. pilot license of appropriate type if aircraft, drivers license if a car, HGV license if a HGV, boating license if a boat). In this operating mode it wouldn't be a drone at all (although having drone capabilities might subject it to certain regulations, such as transponders and whatnot).

            If the same device this time was now being remote controlled, it would now be operating under the appropriate regulations.

            If it was being run in autonomous mode, then it would run under those regulations.

            The capabilites are not mutually exclusive. The operational regulations under which a device would be operating at point in time would depend on what mode it is operating in at that point in time (plus any general requirements that apply to all craft with certain capabilities whether actually in use or not).

            1. Anonymous Coward
              Anonymous Coward

              Re: Failsafe?

              Philosophy apparently eludes you. So never mind.

              But in concrete legal terms in the US, as I suspect elsewhere, the regulations that apply to UAVs hold the PIC responsible for compliance and safety of operation and do not change with mode. The question of autonomy, however defined, is irrelevant here. If you launch it, it is you flying it.

    2. MiguelC Silver badge

      Re: Failsafe?

      Re: "I don't fucking care if your drone crashes and gets wrecked, that's a part of the hobby that we all have to deal with - you put the safety of other people first - drones can be replaced, people cannot."

      And what do you propose as failsafe for a plane with no autonomous navigation? Shut the engine down if signal is lost? Because of course that way it'll stay put and absolutely not crash...

      1. Anonymous Coward Silver badge

        Re: Failsafe?

        Personally, I'd suggest that it should adopt as tight a circular route as it can - eg bank right and pull up.

        That way its position won't drift too much and the operator stands a chance of getting in range / replacing controller batteries / whatever. It also means that once the fuel runs out it will make the undignified landing around where it was flying, so reducing the risk to others.

        1. Clive Galway

          Re: Failsafe?

          This is an autonomous feature - without autonomy there's basically no point - it probably has no gyros anyway, so it has no idea whether it's currently level or what, so has no concept of what "banked right" is. You can't just input right roll constantly, as that would send the aircraft into a constant corkscrew roll.

          1. Mark Honman

            Re: Failsafe?

            The normal setup for planes' failsafe is some rudder, and throttle cut. If all goes well, the plane glides in a circle. If not, it hits the ground in the reserved flying area.

            Failsafe mandatory for models over 3.5kg (likely to be the case here unless this was a very light build).

            1. Anonymous Coward
              Anonymous Coward

              Re: Failsafe?

              Its likely to be balsa wood/ foam and a glow engine but I suppose petrol engines are also possible now. 1.7m wingspan us gotta be under 2.5kg BTOW

      2. Clive Galway

        Re: Failsafe?

        >And what do you propose as failsafe for a plane with no autonomous navigation? Shut the engine down if signal is lost? Because of course that way it'll stay put and absolutely not crash...

        This is EXACTLY what ALL of my drones have.

        If you have lost control link and you have no autonomy, it's going to come down SOMEWHERE anyway, and not in a controlled manner, so you might as well cut the engine to try and reduce the potential danger to other people.

        If you don't do this, things like what happened in this article are the most likely outcome.

        If you do enable a failsafe, it's likely to come down a lot closer to you (And quite possibly not have reached a road etc by then), and the motors and props will not be spinning, so all you have to worry about is the initial impact, and the impact speed is likely to be reduced.

        Obviously in the case of a fixed wing which is relatively stable without control input anyway, you don't failsafe immediately, you give it a good 5-10 seconds timeout, but on all my multirotors, the failsafe timeout is very very short

        1. cageordie

          Re: Failsafe?

          Believe it or not this was thought about half a century or more ago. The solution was to apply some rudder, cut the power, and wait to see what happens. A well setup plane will circle down slowly to the ground and, with luck, land somewhere accessible without getting trashed too badly. Even uncontrolled gliders used this, they stuck a glowing wick, known as dethermalizer fuze, which burned down and broke an elastic band which allowed the rudder to be pulled to a set position. People have been ingenious and attached to their many hours of work for many decades.

          1. Potty Professor

            Re: Failsafe?

            Back in the 60s, I used to fly a 4 foot wingspan glider. It had a Dethermaliser attached to the rudder and elevarors, and was radio controlled. One day, while my mate and I were flying it from Goldhanger Common, in Essex, everything went wrong, I lost the radio link and the glider continued flying staraight and level, and later, the D/T failed, so it continued flying approximately east. We followed it in th car, but lost it out to sea somewhere near Tollesbury, when we ran out of road. Never recovered it, probably crashed into the Norrth Sea somewhere.

          2. Snapper

            Re: Failsafe?

            That takes me back to the time my first big glider flew 40 miles across Surrey because the dethermalizer either fell off or went out.

            I was only 8 and my dad never let me hear the end of it because he had to go and get it, and pay for the broken pane of glass in the greenhouse that stopped it.

            1. phuzz Silver badge

              Re: Failsafe?

              How did your dad find it? Just keep driving in the right direction and asking at every house if they'd seen it?

      3. nijam Silver badge

        Re: Failsafe?

        > drones can be replaced, people cannot

        Given the grotesque overpopulation of the planet, it is clear altogether too much replacement of people has been happening.

    3. JimboSmith Silver badge

      Re: Failsafe?

      WTF? What kind of arsehole does not enable a failsafe on their drone?

      IMHO it's grossly irresponsible to not disable the engine if you lose control link for an extended period.

      Then you get the situation where a friend of mine was almost hit on the head by a falling drone. The pilot came racing over and apologised after this thing had dropped like a stone out of the sky. Apparently he'd managed to go out of range and as a 'safety feature' the engine therefore had cut out. It was within about half a meter of her when it hit, whilst she was standing in her field playing catch with her dog. She said a parachute wouldn't have been a bad idea if the engine shut down for any reason.

      1. Clive Galway

        Re: Failsafe?

        It's a legal equirement to enable failsafe if the RC equipment supports it.

        A parachute isn't exactly feasible - you would need to store it inside something (So that the wind does not catch it and deploy it during normal operation), then some way to open that compartment and eject the parachute. Plus of course a parachute is probably going to have zero effect if flying quite low as it will not have time to slow down the drone.

        It's entirely likely that the guy broke one of the other rules (Flying beyond line of sight, not having a spotter, not flying within a certain radius of uninvolved people etc)

        1. JimboSmith Silver badge

          Re: Failsafe?

          She has a point, light planes have parachutes. Just store the parachute at the top of the thing with a spring loaded cover and a spring platform to push it out.

          I don't know all the details but he was flying it on a large private estate which she lives close to. There was also a sudden very strong wind for a small period preceeding the crash. I do know for a fact that his equipment suffered from both the crash and her black Labrador chewing it.

          1. Anonymous Coward
            Anonymous Coward

            Re: Failsafe?

            Yep, a dog chewing my equipment would cause great suffering.

            1. The Oncoming Scorn Silver badge

              Re: Failsafe?

              Well I can see why you posted that personal predilection as AC, meanwhile back to drones & model aircraft.

              This is well worth a watch or several.......



          Re: Failsafe?

          If the signal is being jammed, then no loss of signal can be detected. Instead the signal is being over ridden by a stronger and constant signal, which prevents any control OR any failsafe.

          1. cageordie

            Re: Failsafe?

            Seriously, you think a receiver can't tell it's being jammed? This isn't high end electronic warfare, it's just noise. Why would loss of control signal not allow a failsafe to operate. These things are pretty crummy and simple, but spotting a loss of good control signal is trivial.

          2. Stoneshop Silver badge

            Re: Failsafe?

            The more crude type of jammer, as available from your Chinese tat bazaar of choice, jams by just swamping a nearby receiver's front end with noise. Crude but usually effective.

            This just makes the receiver adjust its sensitivity downwards until the desired carrier signal can't be locked on to any more. And no carrier lock is a condition that can easily be detected.

      2. Anonymous Coward
        Anonymous Coward

        Re: Failsafe?

        If it goes out of range, wouldn't the best failsafe course of action to be to turn around?

        1. agurney

          Re: Failsafe?

          If it goes out of range, wouldn't the best failsafe course of action to be to turn around?

          Not if it's heading home when the signal's lost.

          1. zuckzuckgo Silver badge

            Re: Failsafe?

            If it flew in a circle for as long as the fuel allows it would give the operator a chance to try and regain contact. It would also limit the area needed to search for the "landing" site.

          2. Anonymous Coward
            Anonymous Coward

            Re: Failsafe?

            True :-) But the signal is more likely to be lost as it travels away from you!

        2. TDog

          Re: Failsafe?

          Good idea, that way you would not see your pride and joy disappearing into the distance. (And I used to fly free flight models).

    4. cornetman Silver badge

      Re: Failsafe?

      I get all the downvotes but as a one-time radio modeller myself I do wonder if something cheap could be made available that provides for some kind of failsafe for signal loss.

      Having said that, loss of contact with a radio controlled plane is not all that common. The radio equipment typically employed on these scale models is rather better quality and more powerful than what might be found in a lot of cheaper drones. I'm inclined to agree that some kind of radio jamming is likely.

      1. Richard 12 Silver badge

        Re: Failsafe?

        A basic failsafe is built into all the 2.4GHz receivers. It sets all control values to pre-determined values.

        For fixed-wing you'd usually set engine idle or stop, ailerons and elevators zero'd and rudder a little left or right. That makes it glide down in a circle near the club.

        Hopefully it lands without much damage

        For rotorcraft it depends. Some have return-to-takeoff, some just cut everything and drop.

        1. Joe W Silver badge

          Re: Failsafe?

          Hm, my experience is... let's say "dated", it used to be that you had to have active input for the control unit to transmit - so "loss of signal" is difficult to detect. Absence of a signal could just be neutral steering input.

          That said, most (I guess all) are now in the digital realm, where things might be handled differently.

  3. Pete 2 Silver badge

    Anyone's fault but my own

    > Instead of staying in the circuit at the model flying club's airfield

    The guy's excuse would be a whole lot more convincing if other club members had (in the past) reported jamming activity.

  4. Anonymous Coward
    Anonymous Coward

    Article correction

    From the article:

    > Even the Hatton Garden jewellery thieves used a GPS jammer

    However the linked Scotman article says: "used a 2G mobile phone jammer to block the alarm signal" which makes more sense than a GPS jammer, after all they were not stealing (i.e. moving) the vault itself lol

    1. Anonymous Coward
      Anonymous Coward

      Re: Article correction

      Good point, but downvoted for "lol".

      1. ICL1900-G3 Bronze badge

        Re: Article correction - ré lol

        Quite right!

    2. Anonymous Coward
      Anonymous Coward

      Re: Article correction

      If they cut the phone lines first then the alarm company will log a 'contact lost' and eventually someone will investigate but if they also had a 2g radio backup then that should still be available to maintain contact with the alarm company

      In the case of those cashpoints in corner shops, they should be able to track the ram-raiders via a battery-backed GPS/GSM radio modem as they drive away with it in the bucket of their JCB

  5. Anonymous Coward
    Anonymous Coward

    the authority was told

    >"the authority was told that "no such [jamming] devices were in operation"

    "Told" by who? The supposed perpetuators?

    "We asked the people doing illegal things if they were doing illegal things. They said no."

    Why doesn't it say that they went out and measured it? Why does it say they were told? Obviously they can't measure it now, they've essentially tipped them off.

  6. Clive Galway

    To everyone downvoting me for suggesting that he should have enabled failsafe

    I am sick of people who are ignorant of R/C down-voting me, so have withdrawn my original post.

    It's a LEGAL REQUIREMENT under CAA law CAP658 that you must enable failsafe (Turn motors off) in the event of a loss of control link if your equiment supports it (Which nearly everything does)

    So if this dickhead let his 1.7m behemoth happily fly off into the sunset and come down some distance away with the engine still running, he is entirely at fault, whether jammers were involved or not.

    The BMFA (Which this guy was almost certainly a member of) guidelines clearly lay out the rationale behind this:

    "The fitment of a failsafe performs three vital functions in the event of a loss or corruption of the R/C signal.

    The primary purpose is to reduce the potential energy of an aircraft that is no longer responding to commands from the transmitter and is therefore likely to crash.

    Taking away the propulsion source can significantly reduce the energy of any impact thereby reducing the potential for injury or damage.

    Secondly, the closing of the throttle on loss of signal serves to significantly reduce the potential radius of the impact area, with the primary aim that any impact will be on the “live” side of the flying activity; this is particularly important at displays and public events but also relevant at the club field.

    The third aspect of the closing of the throttle is that it prevents an out of control model aircraft from climbing once the signal has been lost and presenting a hazard to full size aircraft or entering controlled airspace."

    This has NOTHING to do with autonomy - your model does not need autonomy to do this, it's a feature of the R/C control link

    TLDR you put the safety of other people first - if this means that your model gets wrecked, so be it - that's a part of the hobby that us UAV pilots must deal with.

    1. Gavin Chester

      Re: To everyone downvoting me for suggesting that he should have enabled failsafe

      TLDR you put the safety of other people first - if this means that your model gets wrecked, so be it - that's a part of the hobby that us UAV pilots must deal with.


      The folks flying models like this are almost certainly following all the guidelines and flying responsibly. They know the rules, and should have failsafe's installed and set up.

      If you look at the AAB report its a 2.3M wingspan model, that will be a few hundred pounds of model (maybe getting for for a thousand) to get up in the air, Its not the sort of thing a new flier would have. The pilot had a B certificate, which is what is normally what you would need to show you are of a level that your considered safe to fly public displays.

      There seems to be some people who think a failsafe is the answer to everything, and Clive is completely right in saying what we should already have set up to try and minimise risks. HOWEVER failsafe's are not foolproof, they work on the basis that is a signal is lost they move to either to preset settings, OR keep the throttle and control services at the same state to try and fly though the interference.

      Failsafe's also will not work if the batteries fail, but the batteries were checked before flight and remember they are relatively cheap and mass produced electronics and so some will have issue from time to time.

      Full on autopilots are also not really common in model planes, the skill in the hobby is flying the model, not pre-programming a PC.

      Its very easy to say the flyer was negligent, but it sounds like they were reasonable competent, and did preflight checks.

      Interference happens, sometimes you fly through it, sometimes it causes a crash, As Clive said as responsible fliers we have to try and take precautions to minimise the kinetic energy to try and reduce the risk of dameage to the model, the surrounding and above all to any person in the area.

    2. bazza Silver badge

      Re: To everyone downvoting me for suggesting that he should have enabled failsafe

      I'm not knowledgeable about how loss of signal is actually determined on these R/C receiver systems. If it were simply a signal strength estimation, just plain old barrage noise jamming might be sufficient to stop that measurement dropping in to the "too low" zone.

      2.4GHz? Seems a strange band to use; I thought there was a dedicated band for R/C aircraft here in the UK. Anyway, a sufficiently pokey jammer at 2.4GHz (or a cellular band) could overwhelm the out of band rejection of filters tuned to other frequencies, make a mess of things that way.

      1. Clive Galway

        Re: To everyone downvoting me for suggesting that he should have enabled failsafe

        > I'm not knowledgeable about how loss of signal is actually determined on these R/C receiver systems

        With these systems, you have to "bind" the transmitter to the receiver (So that one person can not controlling another person's aircraft).

        If the system is not able to get packets that it can identify as coming from the bound transmitter, that is considered a loss of control link - so just spewing random data on 2.4G is going to cause that to happen.

        Even if you are not touching any of the controls on the transmitter, it's still constantly sending packet updates, so it will know if it has lost connection.

      2. Mark Honman

        Re: To everyone downvoting me for suggesting that he should have enabled failsafe

        Since 2.4GHz has all this interference - and on the positive side, multiple models can operate on the same frequency - signal loss is more like "I haven't received a packet for X seconds - it's time to panic".

        Most systems hop between different channels of the 2.4GHz band so if one channel is occupied by someone downloading the internet, it's still possible to get a packet through via a different channel.

        1. sanmigueelbeer

          Re: To everyone downvoting me for suggesting that he should have enabled failsafe

          "I haven't received a packet for X seconds - it's time to panic crash".


      3. cornetman Silver badge

        Re: To everyone downvoting me for suggesting that he should have enabled failsafe

        > Seems a strange band to use; I thought there was a dedicated band for R/C aircraft here in the UK.

        When I used to do it years ago, IIRC it was a number of pre-determined channels in the 27MHz or 40MHz bands and you had a coloured flag on your transmitter aerial to advertise your currently selected channel though things may have changed since then: that was goodly long time ago.

        1. Lord Elpuss Silver badge

          Re: To everyone downvoting me for suggesting that he should have enabled failsafe

          Yeah 27 and 40MHz were the analogue reserved bands. 2.4GHz is the direct equivalent of these in the digital domain; and used for everything from Wifi to walkie talkies to cordless phones to RC models.

          1. W4YBO

            Re: To everyone downvoting me for suggesting that he should have enabled failsafe

            "...Wifi to walkie talkies to cordless phones to RC models."

            The big noisemakers in the 2.4 GHz band are microwave ovens. But, at least it's easy to direction-find a 1000 watt interference source.

            P.S. If you have a pacemaker, please buy a leakage meter. Microwave ovens *all* leak.

        2. Gavin Chester

          In Model Flying Geek mode...

          In the "old" world it was 35Mhz that was dedicated to airbourne models (Plane, Heli's and Gliders)

          While historic, 27Mhz was originally for general RC use but later became the frequency of choice for surface use (ie cars) , and 40Mhz could be used for any surface model but tended to be used for marine (ie boats and subs). 27Mhz had 6 channels but later was expanded to 32, and 40 Mhz has 30 or so possible channels. 27Mhz originally used differently coloured flags to show frequency in use, but as the band was expanded a black flag and channel number was used, 40Mhz use a green flag and a channel number and 35Mhz used a Orange flag with a channel number on it as there are 35 potentially useable channels on 35Mhz.

          Almost all of these frequencies used an analog transmission mode, with no way to differentiate between transmitters. You CANNOT have two models active on the same frequency, as the radios will swamp each others signal, and the receivers not know which one is which. All model flying clubs had strict rules on who could turn on their transmitter at any one time, (as its obviously more serious in aircraft than cars if you lose the connection).

          When we started to see cheaper Chinese toy models appear on the market (personal imports, or sellers not caring as they cashed in on a craze) we saw these toys being built for a global market and so saw any of the frequencies potentially in use, so you saw sometimes saw cars on 35Mhz, or planes on 27Mhz. You also say some models on 49Mhz, 72Mhz or 75Mhz, none of which are permitted in the UK, but that didn't stop them appearing.

          There nothing wrong with 35Mhz, I still fly it, and its as safe as any other frequency, in fact potentially slightly safer as its dedicated to airborne models only, but its getting harder to buy new hardware for it as people have moved to the 2.4Ghz that uses a digital transmitting mode that can offer more features.

          Now we are on 2.4Ghz many receivers have more electronics in them and most "bind" to the transmitter, so they should only responds to command from the transmitter they are bound to, think of it as akin listening for a serial number in the transmitted signal. As 2.4Ghz can be used for any model there's no need for makers to make three versions of a controller, one surface, one air and one marine, although some car transmitters are made with steering wheels as some people prefer them.

          In theory as long as the receiver can "hear" the transmitter its bound to it should be OK, and will disregard any other transmitters signal. but there have been issues where the binding was programmed wrongly by the maker so it didn't work that way. 2.4Ghz systems usually do frequency hopping (some early ones did not) so interference should not be a big issue as it should hop away from the channel with interference, but if the entire band is jammed that will still be a problem. If there were jammers in use, they are probably blanketing the band as cellphones frequency hop too, and given frequency jammers are illegal they may not be that great on quality control so may be more powerful than needed, or poorly build and so may well bleed over to other frequencies than just cellphone ones.

          Coat icon for very obvious reasons :)

      4. Man inna barrel

        Re: To everyone downvoting me for suggesting that he should have enabled failsafe

        Loss of signal is easily detected. The controller sends a regular "ping", and the receiver detects loss of signal if the ping is not detected within a timeout period. This kind of arrangement is a requirement for wireless fire alarms, so you can guard against loss of signal from an alarm unit, in the same sense that a tamper loop detects a broken wire in a wired system.

  7. steelpillow Silver badge

    2.4 GHz? Sanity check, please?

    2.4GHz is the ISM frequency band set aside for unregulated uses such as WiFi and car keys - and microwave ovens (well, strictly its centre frequency is 2.45 GHz but, due to sidebands and shit, it spreads itself around a bit). Sufficiently low noise for signal reception at any given moment in time is not guaranteed; you just have to try again later, and if there's a lot of noise around that might be significantly later.

    Mobile phones and GPS use other frequency bands; GSM runs up to around 1.9 GHz, UMTS (3G) up to 3.5 GHz but in fits and starts, carefully avoiding 2.4 GHz.

    So what was actually going on in that lorry park, when nether the characters involved nor the reporters had a clue about all this, is anybody's guess.

    From what has actually been said, some trucker dinging up their Pukka Pie in a grubby microwave in the back of their cab is the most likely scenario.

    1. Version 1.0 Silver badge

      Re: 2.4 GHz? Sanity check, please?

      2.4GHz ISM is used for lots of things and is pretty much "unregulated" ... which means that it's quite unreliable. So it's cheap to use but that does have a cost as this crash demonstrates.

      "The big difference between RF communication for money and RF communication for free is that RF communication for money usually costs a lot less." - Brendan Behan (updated for today's world).

      1. Refugee from Windows

        Re: 2.4 GHz? Sanity check, please?

        Was it the 27th April? Possibly in the evening? It could be that a licenced operation desensed its receiver. The SHF UK Activity Contest may be the cause.

    2. martinusher Silver badge

      Re: 2.4 GHz? Sanity check, please?

      2.4GHz R/C equipment is quite sophisticated but its not infallible. Among our R/C sailplane club there's more than a few instances of planes going into 'hold' or even crashing due to radio problems. Since we don't have a truck park anywhere near our flying site(s) the obvious culprit for us at least is someone's WiFi access point.

      I did a lot of work on WiFi back when it was first being tested so its quite obvious what's going on and why. The problem is communicating this to people. Everyone has grown up with the idea that radios are 'tuned' so this idea is ingrained in our culture. The fact that modern radios don't is difficult to get over as are the consequences of this, especially in an overcrowded band like the ISM. We are sharing our spectrum with all sorts of junk and the result is that the noise floor lifts and the error rate of our communications increases. This has numerous consequences. One is that our WiFi refuses to deliver the data rate shown on the box, especially if we're sharing our spectrum (and here its really difficult to get the idea over that, yes, you are sharing the spectrum with your neighbors -- they have to be able to read your signals to be able to make the protocol work). This is disappointing to consumers who fight back by buying equipment that uses as much power and as much of the spectrum as possible. This crowds out other users. R/C aircraft have to pick out their control data among all the junk and when they don't they maintain their last data -- they 'hold' and eventually they'll go into 'failsafe' if its been programmed. Depending on the make of the R/C kit used by that Harvard (and whether it survived the crash) the owner should be able to pull counts off it. He'd be surprised just how often that R/C signal drops out, even if he's flying in quiet areas like the one we use.

      This problem is why I've been slow to move from 72MHz (the aircraft R/C frequency in the US). My advice to R/C owners is if they have anything more valuable than a park flyer that they look into using other bands like 900MHz. European manufacturers supply radio kit for these frequencies -- it won't be as cheap as the generic 2.4, though. There are also other options for particularly valuable models, including dual radio setups (also dual batteries) and autopilots that will help keep the plane flying if communication is lost.

      1. katrinab Silver badge

        Re: 2.4 GHz? Sanity check, please?

        I thought 900MHz was one of the GSM bands, in the UK initially allocated to Cellnet (now O2), and Vodafone, though probably some of the other telcos have allocations there now.

  8. FrenchFries!

    Rx/Tx Range check

    Most modern transmitters and receivers have a range (and x,y,z telemetry) check. But yea, sucks if some dude turned on a jammer mid-flight. Hope the fella had logging enabled to prove it.

  9. Mark Honman

    Mobile phone jammer doesn't make sense

    mobile phones operate on licensed spectrum - totally different frequencies from the 2.4GHz unlicensed spectrum used for wi-fi, RC, bluetooth etc.

    When used for RC the transmitter makes a lot of retries to address the problem of interference.

    Most likely the issue was a receiver lockup, which I have seen happen a couple of time with a particular make of RC gear.

    As for me, I just suffer from brain lockup.

    1. bazza Silver badge

      Re: Mobile phone jammer doesn't make sense

      You're making an assumption that an illegal device none the less plays nicely with all other non-cellular bands in the spectrum.

      My guess is that the scumbag manufacturers don't give a toss whose services their kit stamps all over, cellular or not. To selectively jam just the cellular bands would cost more than just blatting the hell out of everything.

      1. ClockworkOwl

        Re: Mobile phone jammer doesn't make sense

        I guess it isn't really necessary for something to be a 'jammer' to jam the signal...

        There are plenty of illegal 2.4Ghz video senders (analogue signal) with somewhat ridiculous power outputs. 25mW (the legal limit in the UK) is a bit flakey over distance, so I can imagine the more powerful (2W and more) units finding their way into security camera setups.

        If your RC setup has played nicely (LBT etc.) with the other transmitters, and found it's chink of frequency space, it's easy for a somewhat broadband, analogue signal to swamp it out.

        I do wonder about failsafe issues, but a big bird like this will possibly 'idle' a long way...

      2. phuzz Silver badge

        Re: Mobile phone jammer doesn't make sense

        Or possibly it was a jammer aimed at 2.4GHz wifi. Or more likely it was a perfectly normal source of noise like an actual wifi access point, or a microwave oven.

      3. Man inna barrel

        Re: Mobile phone jammer doesn't make sense

        The receivers used in remote control might not be selective enough, so strong interference at a nearby frequency can block the wanted signal. It costs money to put in the necessary RF filters.

        The cheap receivers used for car central locking were notoriously open to interference. You could get locked out of your car just by stopping at a petrol station, because the lighting caused enough interference to jam the receiver. I hope such receivers are now banned. I know the AA and RAC cursed the things.

    2. Yes Me Silver badge

      Re: Mobile phone jammer doesn't make sense

      What does make sense is vehicular remote control jammers. They are a real thing and are apparently used by vehicle thieves - if the remote is jammed, the driver may believe they've locked the vehicle when they've actually left it open. A lorry park seems a very likely place for a remote control jammer to be used, and of course it's the same frequency band. What I don't know is the range of such jammers.

      (I sometimes park in a supermarket car park that is right next to an automatic car wash. Apparently some car washes operate remote control jammers to avoid nasty surprises inside the car wash. There is a region of the said car park where I have to manually lock and unlock the car - the remote simply doesn't work, and if I had an RC drone I bet it wouldn't work either.)

  10. Anonymous Coward
    Anonymous Coward

    Once Upon A Time, A Long Time Ago........

    ......some of us used the 27MHz band for radio control. We used superhet radios where the transmitter and receiver were locked into a very narrow bandwidth by using crystal controlled equipment.


    So today we use broadband, shared bandwidth equipment. Once again I do wonder about so called "progress".


    Just saying!

    1. ClockworkOwl

      Re: Once Upon A Time, A Long Time Ago........

      That's 27Mc/s I'll have you know!

      And fly aways were much more prevalent back then, there's a whole section on mitigation in one of the old (60's) Aeromodeller annuals...

      All you needed was someone to turn up and test their own transmitter!

    2. saabpilot

      Re: Once Upon A Time, A Long Time Ago........

      And Take Over of model aircraft was also a problem after discovert of the freq they were using by looking at the colourd flag on the anttenna. so expensive model start to use encryption protocols.

  11. This post has been deleted by its author

  12. Peter Christy

    Basic common sense...

    I've been building and flying RC models since 1965. Modern R/C equipment is extremely sophisticated, and in particular the 2.4 GHz "spread Spectrum" radios have an enviable reputation for reliability.

    The fact that this aircraft continued to fly under power after a loss of signal tells me one of two things. Either 1) The pilot had neglected to set the "fail-safe" or 2) the airborne equipment suffered a total power loss.

    Setting the fail-safe to at least shut the throttle in the event of a loss of signal is a no-brainer. It will bring the aircraft down very quickly before it has chance to travel a significant distance and do much damage (most flying sites tend to be pretty remote from civilisation). Any serious modeller will do this as a matter of course. If the fail-safe were NOT set, the controls would hold their last commanded position until either the signal was regained or the thing crashed. However, this would also happen if there were a total power loss of the airborne system. This latter explanation, in my humble opinion, is by far the most likely scenario.

    Most large models will have a power redundancy system of some kind, but even these can cause problems on their own, and tend to only be used on the largest and most valuable aircraft.

    Anyone who has spent a lot of time and effort building a complex model will take all possible steps to preserve it, but we are all at the mercy of the occasional mechanical failure at the end of the day, be it a solder joint, switch or even a cell failure in the battery pack. Fortunately these events are rare, otherwise they would not be headline news material, and even full-size aircraft can suffer from similar problems.

  13. Throatwarbler Mangrove Silver badge

    WWII replica

    Are we sure it wasn't a Mitsubishi A6M?


    A drone is any craft without a person on board. It can be autonomous or remotely controlled. A drone also does not have to be a hovering quadcopter. Military or any long distance drones are winged and NOT quadcopters.

    As for jammers, one would think they should be easy to trace, since their signal has to be stronger than what they want to override.

    1. Screwed

      If a pilot bails out, or dies, does his plane suddenly become a drone?

      (I know my father bailed out of a Wellington in about 1943.)

      The signal need only be stronger from the perspective of a device. Could be very localised and directional, hence not easy to detect from a significant distance away on the ground. Also, if fitted to or used in a vehicle, that vehicle might have moved by the time anyone investigates.

      1. phuzz Silver badge
        IT Angle

        If a pilot bails out, or dies, does his plane suddenly become a drone?

        I guess it depends on if it's got an autopilot, or is remotely controlled.

        Some of the early military 'drones' were conventional aircraft filled with explosives and fitted with a remote control system. However, as the controls weren't that sophisticated, they required human pilots to take off, who would then bail out once they were in level flight, leaving the aircraft to be controlled from a following (crewed) aircraft. It would then be crashed into an enemy target.

        That was the plan anyway, it never really worked out, see Operation Aphrodite.

        JFK's older brother died when the aircraft he was piloting prematurely detonated, before he could jump out.

        There's also a few accounts of pilots who bailed out of an apparently stricken aircraft, only for it to continue flying for quite some time. fore example. Some even manage to make a relatively safe landing.

    2. nijam Silver badge

      > A drone is any craft without a person on board

      Alternatively, a drone is the sound made by government spokespersons when said government is stirring up controversy so they can get something banned.

  15. Andy3

    There is so much frequency-sharing now that this type of thing is becoming more likely. AFAIK, there are currently two model control frequency bands in use - 49 MHz and 2.4 GHz. The latter is crammed with signals from routers, wireless CCTV installations, bluetooth devices and baby monitors, plus microwave ovens which despite rigorous safety regs can radiate quite a potent signal over a distance. Some devices are designed to 'listen' on a frequency before using it but others use brute force, such as phone jammers. I'm a radio amateur and we have a band of frequencies at 2.3 GHz, but it is becoming very difficult to operate there with so much 'junk' nearby.

    1. Peter Christy

      49MHz is only used for short range "toy" applications, not for serious models. In the UK, 35 MHz is available almost exclusively for airborne model control (there are a couple of channels within it shared with low power telemetry signals). We also have access to 459MHz, shared with paging and other low powered telemetry systems, as well as 2.4 GHz.

      As 459MHz is only used in the UK, there is virtually no commercial equipment available on this band. Anyone using it will likely have made their own equipment, or have modified 433MHz equipment.

      The attraction of 2.4 GHz is that the combination of spread spectrum and frequency hopping offers a highly robust communications channel. Not only is the signal difficult (but not impossible) to jam, but the vastly greater bandwidth permits a much higher rate data transfer, as well as allowing more data to be transferred without introducing latency. This latter was an issue on the "narrow band" systems operating on VHF and UHF frequencies, where adding "fail-safe" information and the like introduced a perceptible time lag into the control response.

      All type approved equipment on 2.4GHz has to be designed to minimise interference with other users of the band - even though this is inherent in spread spectrum operation.

      Most model flying takes place in wide open spaces, so things like wifi or microwave ovens are not really an issue.

      Moving on to the "drone" issue - there is actually no legal definition of a drone. All the legislation covering "drones" refers to "Unmanned Aerial Systems", or UAS. "Drone" is a popular term for these devices, but has no legal standing. UAS, as its name suggests, applies to any unmanned aircraft, be it an RC model, an autonomous (or semi-autonomous) multicopter or a Predator military aircraft.

  16. Stoneshop Silver badge

    since their signal has to be stronger than what they want to override

    There'll be a distance factor playing its part. Signal strength for a transmitter goes down with the square of the distance, so even a weak jammer (or just a wonky microwave) can easily blot out the signal from a legitimate source two orders of magnitude further away.

  17. Fursty Ferret

    Suspect that it's less likely to be a phone jammer and more likely to be a dodgy microwave oven or something at the distribution park. This would account for the short term interruption that couldn't be detected by the AAIB or OFCOM (if they investigated).

    Off the shelf autopilot boards are cheap and reliable (dual IMU, dual GPS etc etc for less than a hundred quid), and could easily take over to return the aircraft towards the site of launch while in a glide descent. Ardupilot can even autoland back at the launch site in the event of signal loss.

  18. AClough

    *Pedant mode on* I think you'll find Lichfield is a city, not a town

  19. saabpilot


    This problem is really inevitable if you confine everything to one small spectrum that was originly designated "Free Radiation Band" under International Telecommunication Union, and UK's Wireless Telgraphy Acts, as it wasnt much use in telecom as it is also the resonant frequency of water so signals get absorb by the water vapor in the air. It was to be used by designers to dump their EM noise there, and became popular for other stuff. Because you didnt need a licence. something that was always difficault in the UK. We now have almost everything running in this band now. So it's totally jammed up.

    The solution is to reallocate the RF spectum for MODERN unlicensed communications requirements as most of the spectrums allocation is historic going back to the 1940's and was controlled by the wireless comms indusrtry at that time.

  20. saabpilot

    Sort out your Jouno's

    Mobile phones dont use the 2.4GHz spectrum.

  21. David Shaw

    Once upon a time I was asked to investigate radio problems similar to denial-of-service (jamming) or fake infrastructure (potentially worse)

    Bought all the bits needed for well under £500

    Set up a test, (on neutral diplomatic ground), but managed to accidentally ‘capture’ the GSM phone of the National Data Protection controller himself, as he was visiting a nearby department.

    Where I have noticed active jamming, is the ISM band for car key signals, at some (international) motorway service stations - make sure that your car is locked physically.

    It’s a very low cost attack nowadays.

  22. Paul Cooper

    WiFi range extenders are a thing, and many rely on illegally high power. I can readily imagine a lorry driver using one of these to connect to a distant WiFi source.

  23. myxiplx2

    I smell bullshit

    So the only evidence of a phone jammer is that it's the excuse picked by the pilot who crashed their plane, with zero evidence whatsoever?

    I've been flying R/C models for 8 years and this smells like bullshit to me. Lots of pilots are not as thorough as they should be about radio equipment setup and testint, and given the pilot had clearly not enabled failsafe (a legal requirement in all models, and doubly important in any larger one, with the #1 priority being to cut the engine upon loss or signal), and had also clearly not tested failsafe recently, I have my doubts.

    Also lots of pilots blame external interference rather than accepting fault themselves. There are lots of things to check on the model before looking into wild theories like phone jammers. What radio system was in use, were there redundant receivers, had signal quality been checked recently, was telemetry in use to check signal strength, when was the last range test performed.

    Lots of things can go wrong with R/C gear, a faulty antenna due to vibration of an I/C engine, old or poor quality receivers, low batteries in the transmitter, etc... Until you rule out all the common mistakes, don't go believing a pilot who's trying to blame "phone jammers" when they're likely totally uneducated in how phone jammers even work.

  24. Barrie Shepherd


    ""It was suspected by the pilot that 2.4 GHz jamming devices were being operated by some of the companies at the distribution centre to prevent staff from using mobile telephones,""

    Don't go for that - 2.4 GHz will not stop people using their mobile phones and a company would not want to also jam up their office and warehouse Wi-Fi.

    2.4 GHz on a lorry designed to confuse the GPS tracking systems, that operators spy on their staff with, is more likely - or pilot error!

  25. Anonymous Coward
    Anonymous Coward

    Pedant’s corner

    The Harvard was being used as a trainer well into the 1950s by the RAF.

    Dad flew one before advancing to the Meteor 3.


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