Lost mine today, RTH failed.

The instrument readings in the app give you the information to know those things.
My point exactly. Why then do you 'have to keep visual LOS' at all costs as the poster I quoted suggested.
 
Thanks Meta, good read. I didn't know about the asphalt part. I'm curious why that's problem when there's no rebar in it. I'm not arguing the point, this is just a new datapoint that surprises me. I have launched from asphalt countless times, never had a problem till today.
Ordinary asphalt roads shouldn't cause a problem.
They are just made of compressed crushed rock + asphalt.
But be careful that you don't calibrate somewhere with buried steel pipes or power cables or structural steelwork.
 
There seems to be several posts where it's stated that more than one compass calibration is needed in order to achieve a successful calibration. A better way to look at this is that the failure rate is greater than 0. If multiple bad calibrations occurred then it's likely that a calibration subsequent to the successful calibration will also fail. A failure rate greater than 0 is cause for concern. It's an indication that something is wrong; either the location or the compass itself. A successful calibration after one or more failed calibrations is marginal at best.

Personally, if I had an unsuccessful calibration and thought it was location related I'd move to a new location. If a successful calibration is achieved then repeat calibrating several times to make sure that it's because of the new location. Then I'd take it back to the previous location to see if the bad calibration was caused by that location. If confirmed then back to the new location and 2 or 3 successful calibrations before flying.
 
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My eyesight is not all that good these days, which means I am only allowed to fly 1800 feet away, while my quad is perfectly capable of flying 5km away with 100% control, and I can see my Air 2's screen quite perfectly at 2 feet away? Really?

Even if you still have 20/20 eyesight, are you suggesting that by seeing your quad at 2000 feet you will be able to tell whether it has suddenly developed compass or GPS problems? You will instantly be able to tell if it is reacting properly to RTH instructions? You can tell at 2000 feet whether it is flying forwards or backwards?

I also fly a Blade 350 QX 2 with a GoPro 4. I should have stuck with that, eh?

I can and I have terrible eyesight. Part of the experience that comes from flying RC for 25 years. Tiny dot getting smaller means going bye bye. Tiny dot getting larger means getting closer. Tiny dot going up mean well up. Tiny dot going down means well going down. Left and right should need not explanation.

I do suggest that everyone add some form of contrast improvement to their craft. The white is terrible for long distance location. Blends with the sky far to easy.
 
I am glad for the helpful info from the members of this group so, risking the expected spanking from Snerd for daring to show up in his hobby prior to achieving guru status, I'm going to continue to drill down on this.

If a faulty compass calibration is the accepted explanation I would assume that it went to a false RTH point and landed, right? Since the only obstruction was one very narrow tall building a block away, shouldn't the signal have reconnected once it cleared that building? It would be a huge coincidence that the craft randomly changed course to one that remained directly in that building's shadow. Or so it seems to me.
 
Compass calibration ........
I believe this incorrect, or at least incomplete: IF YOU SET THE RTH HEIGHT in the app before you fly, it will ascend to that value (not 20 m) when RTH is initiated. That value doesn't appear to be completely sticky. Although it seems to stay valid on power on sequences, something returns it to default values (firmware upgrades? - need to watch this).

The fact that this critical bit of information is buried under several menus and is poorly explained may be contributing to the problems we see here. I always check RTH height as part of my preflight setup. At 20 meters, I'm going to hit a tree nine times out of ten. I don't want to run into trees.
Hi Wetdog
Just read this whole topic and ya some of the compass stuff can be confusing but..
That info of ascending to 20 meters IS correct.
What happens, which you can confirm in the simulator, if you set RTH height over 20 meters eg. 50meters and your flying below 20 meters and RTH is initiated by either a Smart RTH or you press RTH button the aircraft will rise to 20meters during which you have no stick control. It will then continue to 50 meters (or whatever you set RTH to) during which if you move the sticks it will stop ascending and head for home.You will have stick over ride so you can affect pitch and altitude but it centers on heading home. I you don't touch the sticks it will ascend to 50 meters(or what you set) and head straight home.
All just as richa's post showed
 
I don't think that's right. I've never seen mention of it in the manuals etc.
Each RTH instance is quite separate and there's no reason it would prevent using again
I have frequently used RTH multiple times in a single flight.
Easy enough to test this for anyone interested..
Smart return to home only works once a flight
 
I am glad for the helpful info from the members of this group so, risking the expected spanking from Snerd for daring to show up in his hobby prior to achieving guru status, I'm going to continue to drill down on this.

If a faulty compass calibration is the accepted explanation I would assume that it went to a false RTH point and landed, right? Since the only obstruction was one very narrow tall building a block away, shouldn't the signal have reconnected once it cleared that building? It would be a huge coincidence that the craft randomly changed course to one that remained directly in that building's shadow. Or so it seems to me.
Androne, what firmware were you flying when you lost the bird?
 
RTH can only work if the RC and Aircraft can communicate. Hope you find it.
Not correct . The phantom only needs a gps signal to work properly . Check sensor mods before each flight . Based on those numbers it's easy to tell if you need a calibration. 1.5 million ft and not 1 single issue with any of my flights .
 
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My eyesight is not all that good these days, which means I am only allowed to fly 1800 feet away, while my quad is perfectly capable of flying 5km away with 100% control, and I can see my Air 2's screen quite perfectly at 2 feet away? Really?

Even if you still have 20/20 eyesight, are you suggesting that by seeing your quad at 2000 feet you will be able to tell whether it has suddenly developed compass or GPS problems? You will instantly be able to tell if it is reacting properly to RTH instructions? You can tell at 2000 feet whether it is flying forwards or backwards?

I also fly a Blade 350 QX 2 with a GoPro 4. I should have stuck with that, eh?
No sir, just saying you are suppose to have a physical sight of your aircraft. Not what you can see on your Air but what what you can see.
 
No sir, just saying you are suppose to have a physical sight of your aircraft. Not what you can see on your Air but what what you can see.
I undestood what you said - hence my reply.

What I don't understand is "why?". Read my post again carefully and answer the questions in there.

If you believe you should always be able to see your quad the you really wasted a lot of money on your P3. A much better buy would have been a Solo or Blade with a half mile Wifi range.
 
Smart return to home only works once a flight
True, but Smart RTH is based on the red/yellow/green battery line at the top of the Go app. Smart RTH initiates when the software determines you have just enough energy remaining in the battery(+ small reserve) to return to the home point. This is only available once during your flight. If cancelled, Smart RTH will not reactivate. The others are still available though.
Not correct . The phantom only needs a gps signal to work properly . Check sensor mods before each flight . Based on those numbers it's easy to tell if you need a calibration. 1.5 million ft and not 1 single issue with any of my flights .

There are 3 RTH modes. Smart RTH (battery energy), Failsafe RTH (loss of RC signal for 3 seconds) and RTH (user initiated). You can activate RTH as many times as you like from the RC or the tablet. I've used it 1/2 dozen times in one flight before.

SD
 
True, but Smart RTH is based on the red/yellow/green battery line at the top of the Go app. Smart RTH initiates when the software determines you have just enough energy remaining in the battery(+ small reserve) to return to the home point. This is only available once during your flight. If cancelled, Smart RTH will not reactivate. The others are still available though.


There are 3 RTH modes. Smart RTH (battery energy), Failsafe RTH (loss of RC signal for 3 seconds) and RTH (user initiated). You can activate RTH as many times as you like from the RC or the tablet. I've used it 1/2 dozen times in one flight before.

SD
???? I never questioned anything about the RTH functions other than needing a gps signal.
 
???? I never questioned anything about the RTH functions other than needing a gps signal.
Sorry Phantom, I wasn't questioning your info. I just quoted your post to preface the differences in all the RTH modes. A lot of users (lately) think they are all the same, and some believe RTH is just an emergency feature, which it can be but there's more to it than that.

No offense intended.

SD
 
RTH for me has been very reliable especially for the phantom 3. That baby turns home right when you initiate RTH.

I had one issue with the p2v when I flew up 1200ft vertical from my position(stupid I know) and lost connection, my bird said it was going to RTH but wasn't moving probably because it was confused but eventually it came down. it was a scary 7 min tho. I thought it was going to run out of battery at 1200ft and come crashing! never doing that again.
It was probably coming down, it's really hard to tell sometimes but it definitely was moving down.
 
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Sorry Phantom, I wasn't questioning your info. I just quoted your post to preface the differences in all the RTH modes. A lot of users (lately) think they are all the same, and some believe RTH is just an emergency feature, which it can be but there's more to it than that.

No offense intended.

SD
Cool no worries . I appreciate you clearing up the confusion with the different RTH functions .
 
Ordinary asphalt roads shouldn't cause a problem.
They are just made of compressed crushed rock + asphalt.
But be careful that you don't calibrate somewhere with buried steel pipes or power cables or structural steelwork.

The problem with an asphalt road or any other man made surface is you just don't know. Calibration may complete and look like it was successful even when there are localized magnetic fields that will skew the calibration. This is why calibrating in a place with the lowest likelihood of manmade objects or other sources of interference is best i.e. a big open field.

I'll admit this is a little paranoid but the compass is the Achilles heel of the Phantom and all compass based AHRS systems. It is the number one cause of calamities.

When I need to calibrate the compass, I go to the same place each time. Once calibrated and tested, I don't touch it until I have to go out of town.
 
RTH is a convenient feature of the Phantom. When returning from a long mission it is a convenience. If you prefer not to use it that's cool but please don't decide for everyone that they shouldn't take advantage of the feature! :rolleyes:

I agree. I use it all the time, and you can have it going to Home Point and pan rear or sideways if you want for some different video perspective.
 
The problem with the suggestions to not recalibrate the compass is, when the app gives a compass error your choices are to recalibrate or not fly because it won't allow the motors to start until a successful recalibration is complete. Unfortunately this happened so often for me I considered it routine. It now seems to me that the app could be better designed by providing a "magnetic interference" warning instead of simply prompting to recalibrate. IMHO
 
The problem with the suggestions to not recalibrate the compass is, when the app gives a compass error your choices are to recalibrate or not fly because it won't allow the motors to start until a successful recalibration is complete. Unfortunately this happened so often for me I considered it routine. It now seems to me that the app could be better designed by providing a "magnetic interference" warning instead of simply prompting to recalibrate. IMHO
I'd be concerned about needing to calibrate frequently. I would try to find the cause.
Near some unseen metal or RFI (large motor behind a wall etc.)?
Problem with the calibration procedure?
Faulty compass in the Phantom?
Software/Firmware issue?
Faulty compass calibration makes the P3 swirl around and doesn't seem to know what to do next.Scary.
I calibrate in an open field then not do it again ( if readings are near 1500) and hover is stable.
I've moved 200 miles and it's still good, yet get near a bridge and the compass goes bad readings but the calibration isn't bad. I'm too close to source of interference. Move away from it and compass is good again with no calibration. Hope that helps someone.
 

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