Helicopters knocking out GPS signal?

[Daaave]

Hi all

New pilot here (less than 1 week)

I was flying this morning at around 100 feet alt and very close to home, a helicopter went past at at least 500 feet, about quarter of a mile away and I lost my GPS signal and the Mavic went to ATTI mode. Very scary for a new pilot. Fortunately I could see the Mavic very clearly and was able to land ok.

Is it normal for helicopters to cause this?

Thanks for your help

 

[waylander]

Hi Daaave

Never heard of such a thing myself, I very much doubt that a helicopter could do that, there is probably another explanation, upload your flight log to HealthyDrones, someone on the forum will be able to come up with an explanation.
Waylander

 

[pixl]

Gotta be a coincidence. I occasionally briefly lose GPS signal when there's nothing nearby. No big deal, don't panic..it happens.

 

[Daaave]

Thanks very much for the replies. This has knocked my confidence a bit, I'll just stay very close to home for a few days.

 

[waylander]

Thanks very much for the replies. This has knocked my confidence a bit, I'll just stay very close to home for a few days.

Yes understand your caution Daaave, not a bad thing, but be assured the Mavic and its control systems are very robust, just make sure you are not near to strong EM interference sources when you take off, so that compass functions are not impaired, and make sure you hear or see visual confirmation that the Home point has been set, and that return to home in the event of loss of signal is set in the software.

A good routine for new OP's is to fly out to a 100" or so and trigger the RTH on the RC, watch the Mavic's response let the RTH function have control for awhile, then cancel it, the Mavic will then happily hover where it is until you make stick movements and take back flight control, this routine will give you confidence in the Mavic, and your ability to control her.

Fly Safe
Waylander

 

[pixl]

While you're getting your confidence back close to home, try doing some confidence-building exercises like flying distinct patterns -- ie figure 8s, squares, etc. Also close quarters stuff closer to the ground -- get an idea of where your drone is in physical space -- it's easy to misjudge. You'll know that you're getting the hang of it when you can instinctively do coordinated stick maneuvers ie combination ascend/yaw/sideways/forward. When you get more confidence in flying it, losing GPS briefly or even longer and flying ATTI mode will be no big deal.

 

[2nckayakers]

It isn't that the helicopter itself is blocking the GPS signal, it is the disturbance of aircraft itself moving in or near the path between you and the satellite signal. Think of it like a rock tossed into the water and the ripple effect that radiates out from it. It is that ripple effect in the air that interferes temporarily with your signal. It doesn't have to be directly in the path just very close. It is very similar to what airplanes do when they fly between your digital TV antenna and the transmitter tower. Most people never notice that interference but I live in the direct flight path of a regional airport so it happens at my house a lot. As Pixl said though, the Mavic has redundancy for that so you shouldn't have any problems.

 

[tcope]

Something as small as a helicopter won't knock you down from something like 13 satellites to something like 4.

A satellite needs to be at 320km minimum. The Hubble telescope is at 600km. GPS satellites orbit at around 20,000km. So they cover a _huge_ portion of the earth. Something the size of a helicopter won't block line of sight from a GPS satellite unless the drone is right next to it and even then, it's only going to block line of sight from 1 or perhaps 2 satellites. You should be locking onto 13-16.

 

[JeffG]

While you're getting your confidence back close to home, try doing some confidence-building exercises like flying distinct patterns -- ie figure 8s, squares, etc. Also close quarters stuff closer to the ground -- get an idea of where your drone is in physical space -- it's easy to misjudge. You'll know that you're getting the hang of it when you can instinctively do coordinated stick maneuvers ie combination ascend/yaw/sideways/forward. When you get more confidence in flying it, losing GPS briefly or even longer and flying ATTI mode will be no big deal.

This ^^^^

I also practise with the drone facing me so you get use to operating the yaw in reverse. good post and suggestions above.

 

[pixl]

One other thing on the skills: concentrate on the stick skills before doing any of the Intelligent Flight modes. And try to avoid flying by FPV until you've mastered this stuff. There is way too much going on on the phone display, and it's easy to let some of that stuff be a substitute for flying skills.

The good thing about the Mavic is that it's relatively cheap -- in the investment is low. I started out on an Inspire 1 Pro, which had fewer kinds of automation (at least initially) and sensors, and I had about 6X as much invested. I didn't start to feel reasonably competent until I had 30 hours in, practicing 2 hours a day -- I had 9 batteries. I suggest having at least four batteries if you want to get good, quickly. That will allow you about 90 minutes per session of flying which is the way to get really good. I didn't really feel like I knew what I was doing until I had 30 hours in.

 

[Daaave]

Thanks again for all the replies.

It happened again (loss of GPS. ATTI mode for a few secs), no helicopters around this time. This time GPS mode came back but I had no control of the Mavic for a further few secs. When I regained control the Mavic was drifting forward and right (no wind) so was very difficult to pilot until the sensors kicked in close to the ground.

Very lucky to land safely again. (and not to have a heart attack)

Pretty sure I have the hardware fault described in this thread..

Spooky Action at a Distance

Returned to Amazon for a replacement.

 

[pixl]

Thanks again for all the replies.

It happened again (loss of GPS. ATTI mode for a few secs), no helicopters around this time. This time GPS mode came back but I had no control of the Mavic for a further few secs. When I regained control the Mavic was drifting forward and right (no wind) so was very difficult to pilot until the sensors kicked in close to the ground.

Very lucky to land safely again. (and not to have a heart attack)

Pretty sure I have the hardware fault described in this thread..

Spooky Action at a Distance

Returned to Amazon for a replacement.

Yeah, good idea. Flying with fear sucks. And buying from Amazon is great in that they take returns with zero hassle.

 

[L.L.]

There have been reports of solar flares yesterday. Can that have an effect on the loss of GPS signal?