Serious RTH firmware bug, are you seeing it?

[Rom3oDelta7]

I'm not certain how to do that, I can't access the .txt log for manual uploading because it is stored on a P4P+ display unit and I don't think I have direct access to the directory. I have synced my flight logs to DJI via the DJI GO app, I assume that uploads the logs automatically. There are also the large .DAT logs stored on the aircraft, not sure if that should be sent or how to send it.

Not sure if the P4P+ is different in this regard, but here is the "usual" process for downloading the logs. Syncing your flight logs in GO will not send the data to DJI. You should contact DJI support and email the logs (.DAT files) you downloaded using the aforementioned process. If you want to get into it, there are various log decoders on the web you can use to convert them into something readable.

 

[ianwood]

I would pull the log and DAT files as indicated above.

 

[smiller]

I could see gaining altitude as an advantage if signal is lost.

You can regain control anytime the aircraft is connected.

The unit should gain altitude to the preset RTH altitude value and no higher, unless perhaps an obstacle is encountered. You certainly do not want uncommanded continuous altitude gain.

 

[Snowwolf]

My last flight of two, at 115 meters height and 500 meters away I lost signal for some unknown reason, it went into RTH and flew back in a straight line staying at 113 meters for 400 meters until I could see it and I then took control and landed, the RTH height is set at 70 meters

 

[smiller]

My last flight of two, at 115 meters height and 500 meters away I lost signal for some unknown reason, it went into RTH and flew back in a straight line staying at 113 meters for 400 meters until I could see it and I then took control and landed, the RTH height is set at 70 meters

That is normal behavior, RTH will occur at your current altitude or the preset RTH altitude, whichever is higher.

 

[Techcop50]

Another pilot just posted this:
Max Altitude Exceeded on RTH

 

[RGsuv9uw]

I and one other P4P owner (so far) have noted an odd and potentially dangerous RTH behavior: Upon either a manually commanded or failsafe RTH the unit will climb continuously while enroute back to home point until it is either stopped by manually exiting RTH, or finally reaches its home point (at which point it will begin a vertical decent.) As far as we can tell the unit will ascend continuously until stopped, or at least we haven't experienced a limit. The pre-set RTH altitude setting seems to have no effect on this behavior.

This is obviously a serious bug since it could potentially cause loss of the aircraft and/or present a danger to other air traffic. The problem may not be noticed over short horizontal distances but over longer routes it is dramatic.

Can you all please see if you can duplicate this behavior? If it is happening on two units it is probably happening on more.

I own a Phantom 4 Pro and can confirm that this is an issue. It has happened twice now. I've attached a screen shot from the first flight during which it occurred.

 

[donogl]

Could somebody with this problem please post his logfile.txt here, specially the recordet values for the throttle stick while ascending in RTH Mode?

https://www.phantomhelp.com/LogViewer/Upload/

I have a Problem with my Phantom 4 descending during RTH and crashing into a tree.
DJI says i commanded it to descent during RTH into the tree by holding down the stick the whole time and it is a operator fault. The only thing i did constantly was trying to abort RTH.

But i had no connection and would never hold down the stick the whole time....... Why should i do this?

Thanks in advance for somebody supporting me with his flight log to check.

 

[WIFI442]

I had the same thing happen! I was doing a distance test in an unpopulated area. I flew out to around 10,000 feet away. I was around 375 feet up and I hit return to home. Wasn't paying attention to the height as it came back (it was bright and sunny, hard to see on my I7+) but noticed the battery seemed to be dropping faster than it should. A little while later I was getting the Max altitude reached warning and it was at 1640 or so feet! It kept bouncing off that limit (500M) trying to go higher but the hard limit kept it at that altitude. I have my max alt set at 500M (I sometimes like to fly up along the hills here). I quickly turned off RTH and brought her down to ~300 feet and flew home. I did use RTH on another flight that day and it worked fine but I wasn't very far away

New P4Pro With Latest FW. I think it was it's 3rd or 4th flight. Great machine otherwise. I was on 5.8ghz mode if that matters.

 

[neven]

I had the same thing happen! I was doing a distance test in an unpopulated area. I flew out to around 10,000 feet away. I was around 375 feet up and I hit return to home. Wasn't paying attention to the height as it came back (it was bright and sunny, hard to see on my I7+) but noticed the battery seemed to be dropping faster than it should. A little while later I was getting the Max altitude reached warning and it was at 1640 or so feet! It kept bouncing off that limit (500M) trying to go higher but the hard limit kept it at that altitude. I have my max alt set at 500M (I sometimes like to fly up along the hills here). I quickly turned off RTH and brought her down to ~300 feet and flew home. I did use RTH on another flight that day and it worked fine but I wasn't very far away

New P4Pro With Latest FW. I think it was it's 3rd or 4th flight. Great machine otherwise. I was on 5.8ghz mode if that matters.

Yup, that is a scenario I predicted few posts up. If you weren't manually RTH with some 70% battery and instead went for distance until Smart (battery) RTH you probably wouldn't make it home because of that climb.


Sent from my iPhone using PhantomPilots

 

[Rom3oDelta7]

1. Has anyone uploaded logs to DJI support?
2. The thread on IMU calibration issues in this forum notes that new firmware is pending. No mention of fixes/improvements. One can hope ...

If you have this issue your/our best hope for a resolution is to open a case with DJI support and send them the logs. See my earlier post on how to download the logs if you are unfamiliar with the procedure.


Sent from my iPhone using PhantomPilots

 

[smiller]

1. Has anyone uploaded logs to DJI support?

Yes, this is very important so if you've seen this specific problem please report it to DJI. Also, if you have trouble finding the .txt flight log files manually you can also sync the flight logs within the DJI GO app and send them to DJI that way, and then follow up by submitting a support ticket identifying which flight they should be looking at.

 

[neven]

This probably has nothing to do with IMU since onboard barometer is registering actual altitude correctly. My guess would be OA but someone tested it with OA off and it still climbed.


Sent from my iPhone using PhantomPilots

 

[smiller]

I tried a few things, including calibrating the IMUs and re-setting the RTH altitude value (with aircraft connected) to another value and then back to the desired value just in case the stored value was somehow corrupted. No change however, every long mission (maybe a mile) resulted in the aircraft climbing steadily upon entering RTH mode (to well above the preset value), and kept climbing until I halted it by manually exiting RTH.

This means that RTH is potentially dangerous on long missions until the bug is fixed. I don't think this is a hardware problem with my particular unit as the aircraft flies perfectly otherwise. I imagine that once DJI has confirmed the issue that it will be corrected promptly due to the possible danger to other aircraft. It is very easy for an unknowing operator to not realize what is happening and inadvertently fly much higher than intended.

I should note that on shorter flights RTH works perfectly (and the precision landing feature seems to work amazingly well BTW) so if you have only flown short missions and haven't seen the problem and thus think you don't have it, I'd think again or make sure you verify all is OK before you attempt to use RTH at longer distances..

 

[JMFinch]

My P3P is set to imperial but RTH remains metric which is about 3 times higher. Could it be that Dji replaced the rth field caption to read feet but still calculates the rth value as meters? Your phantom should not begin flying horizontally 'till reaching that altitude but a bug could exist in the enroute code logic.

 

[smiller]

No, it's listed in meters and again, this is not a mis-setting or misinterpretation of the RTH altitude setting.

 

[daveisim]

Unless I am just not seeing it, basic Trouble Shooting 101 begs me to ask what versions for firmware / software for the P4P, the RC, Go App (or other) and platform for it & it's O/S version.

For both the OP and others. Without knowing the commonality it's hard to figure out what part of the equation is influencing the outcome.

 

[smiller]

Unless I am just not seeing it, basic Trouble Shooting 101 begs me to ask what versions for firmware / software for the P4P, the RC, Go App (or other) and platform for it & it's O/S version.

For both the OP and others. Without knowing the commonality it's hard to figure out what part of the equation is influencing the outcome.

Yes, I was kind of hoping for more feedback from others so Ill ask again:. Has anyone been able to positively determine that their P4P does not have the problem? (i.e., you fly out approx 1 mile or more, press RTH, and the unit does not exceed the preset RTH value on the way back?) You will not see the problem on RTH from short distances so the test must be performed at a range of approx. 1 mile or more. Please report only if you have performed the test exactly as described with a P4P, along with your OS and firmware level. It only takes about 10 minutes and any data will be much appreciated.

I am currently working with DJI support on this issue since I (and apparently several others) can reproduce it at will. I have not flown since the latest formware update however and I will be testing again today.

 

[smiller]

I have just flown with the new firmware and the problem has not changed, upon entering RTH my altitude increased steadily from 75 feet to over 600 feet in less than a mile! RTH altitude was set at 75 feet and there was no control stick input on the way back. Again, this seems to be a very serious bug and I am working with DJI, but any other input would be appreciate. Until this is resolved RTH over longer distances is potentially dangerous and essentially unusable.

I'm surprised that we're not hearing more of this, everyone seems to be pixel-peeping at the camera and not testing more critical flight functions. I suppose it's possible that it's just my unit but I really think not because 1) others have reported the same problem and 2) my unit flies perfectly in every way except for this one RTH issue. If there was a hardware malfunction causing this I'd certainly see it affecting other flight modes.

 

[Snowwolf]

I have a P4P and I lost signal at 500 meters away at 115 metres high and it initiated RTH, looking at the 400 meter fly back it keeps a steady 113 metres altitude all the way back.