Jamming Arducopter? Is that possible?

Strange things happens to me yesterday with Arducopter 3.0.1 and I am thinking about “jamming” my quad by someone else, maybe this is just in my mind. See logs and TLogs attached.

APM2.5, AC 3.0.1, Tx Spectrum 2.4Hz, 433MHz telemetry, no FPV

I was playing with my quadX yesterday for some testing (Loiter, RTL, Stab), was little windy.
First 2 flight were normal, no issue. On 3th flight, when I was on the “air” I did notice a guy behind me with playing (I believe) a Tx remote control with extended antenna (not 2.4GHz), but longer antenna. At some moment, from stabilize position at 6 m altitude, my copter starts to drift and loose altitude and crash in field. I was in Stabilize, I did check that 2 times and see on log also. During this time, I had not any control on my Quad, I did try to roll/pitch and increase altitude, since was loosing altitude fast. No control!.
After the crash I did ask the guy what is he doing there, is an empty field and always I was alone.
He said he crashed his RC copter one day before and did come for finding it. But I was wondering why you need your Tx with extended antenna, when you are looking for your copter.
I do suspect 3 scenarios: brown-out, mechanical-failure, or “jamming”. From the log I did not notice any brownout, HW voltage was OK, battery voltage was 12v after crash (I did check that).
Could someone please try to see which of those 3 scenarios could be the answer?

I did parse all the situation from link below regarding the diagnosing.


Logs are on http://diydrones.com/xn/detail/705844:Comment:1376223 page

I don’t know if you sorted this yet, but RTL was invoked for some reason in the larger of the log files.

Anything is possible but probable is another matter. I don’t know about the law in Canada but here in the US someone intentionally interfering with a computer system can find themselves instantly in very hot water. On the very slim chance that the fellow you saw was up to no good it is hardly likely that he would have let you see him, let alone let you get close enough to talk to him. (And don’t misunderstand, I’m not making light of your raising the possibility, it’s a fair enough question.)

Unfortunately there are people now loudly raising unrealistic fears of UAVs being hijacked or “shot” down by hackers. The motives vary, from genuine if overreaching concern through tin-foil-hat level paranoia to the good old dollar (with the latter probably being the front runner). There may also be persons active whose wish is to suppress UAVs by such propaganda.

In any event, I hope you find the cause - and I’ll bet it won’t be some guy lurking in the bushes with a ray-gun.

In short:
Jamming the R/C and/or the telemetry is possible and technically no problem. If you have a low-quality R/C, it’s actually very easy and happens often enough unintentionally. Google for “Hobby King Orange DSM problem”.

BUT, jamming APM itself is not that easy. That would require a not excessively but still pretty sophisticated attack through the telemetry. In short, the attacker must figure out your network code from the radios and then use a radio which is much stronger than yours. Then, the attacker could take over your copter.

If your copter crashes due to R/C problems, I wouldn’t worry about jamming. I would worry about what you did wrong in the setup, because R/Cs can be jammed by all kinds of stuff and you should set the failsafes up properly. You don’t want your copter to come down on a person or some property due to R/C glitches, do you? :slight_smile:

Here is a little anecdote.

It was a year ago. When i first started to fly quads. While i was hovering in my front yard. Some dude parked his BMW X5 across the road, got out of the car. Locked his doors with key fob. And my quad took off into the sunset.

Being quite new to the RC hobby. I watched my quad fly away with my jaw open for about 3-4 seconds. Quad wasn’t responding to any stick input. After 4-5 seconds(and about 100 meters) my brains cumputer engineer part engaged. And i did what any self respecting IT person would do. I restarted my Radio.

Miraculously i got the control of my quad. But by this time my quad was a spec on the horizon. I had no way of knowing it’s orientation(i didn’t have FPV) and couldn’t use RTL(no GPS). So after some meddling around, i decided to set it to ground(it was an unpopulated area) as gently as i could(should have used LAND switch instead maybe)

Somehow i managed to land, pretty much in one piece. The BMW guy had witnessed the whole thing. Asked me what happened. Told him my suspicion that his keyfob somehow jammed my Radio. He offered to drive me to where my quad landed.

When we got there,i noticed both landing gears were broken, but otherwise my quad was unharmed. So i held the quad in my hand. Armed it again and asked the guy to press the buttons on his keyfob.

When he pressed the unlock button, nothing happened. When he pressed the lock, i again lost control of the quad. We did some more testing. And without fail, his keyfob’s lock button jammed my radio every time.

After that incident, i tested with two other BMW keyfobs. None of them effected my flight.

But since i didn’t want a repeated performance, i got rid of the both TX and RX modules. (FrSky 2.4 Ghz. I believe model was D8X? The one hobbyking sold as combo)

As someone who is at least a little knowledgeable about radio waves. I’m aware how unlikely it is to something like that to happen(especially considering FrSky’s FASST technology) but it somehow still happened.

The lesson i learned from this episode: Never trust technology. Even the predator drones(which costs millions) crash often(about half of the predators ever made crashed), so it’s actually quite amazing how in-often our hobby grade 1000$ drones crash.

I’m not sure about in Canada. Here in the US if someone is flying RC with a long antenna, i.e. about 4 feet, then it’s probably a 72Mhz transmitter. I’m no expert, but this shouldn’t interfere with a 2.4Ghz transmitter.