Worst flight ever with p4p I'm still shaking, no control but got it landed

[Snowwolf]

Hi all
I decided to have a fly today, lovely bright sunny day very minimal wind, before flight it was taking its time finding satellites but eventually it did and said I could take off, once up in the air the bird was totally out of control, it was the worst 10 minutes flight I have ever had, all sorts of warnings were coming up on the screen but I could not take my eyes off the drone as I was having great difficulty keeping it from flying away, sometimes I was full throttle from keeping it drifting away, then all of a sudden it would accelerate fast and needed to full throttle in opp direction, lots of things were happening on screen and with the drone, I did eventually get it back down on the ground, how I don't know, luckily I have flown planes for many years and always fly atti mode with the drone very often in case of flights like I just had, I had a P4 previous to the p4p and have done 160 full flights with no issues, 140 flights being with the P4 so I am pretty good and check everything before a flight.

I have the data log of what has happened in the link below and hoping someone can have a look at it to find out what went wrong.

I have had a look at the flight I done on the iPad Pro which I use, I am running the latest software and firmware, I have taken a few snap shots from the flight, one warming was un paved airport but that is untrue, here are is a snap shot of the screen, I had 14 satellites on take off but looking at the flight on iPad it kept losing them, also it looks like it has only recorded half the flight and only recorded from when I walked to a new position I was getting a lot of warnings of gimbal yaw reached end point
Here is the flight data file folder link and a video from my ipad on how it was flying.

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

https://www.dropbox.com/sh/jomjd ... I6KAvSoRn3iDEa?dl=0

 

[F3honda4me]

Can you get the DAT file instead of the BAK file? How to retrieve a .DAT

 

[F3honda4me]

I watched your video, this looks like a classic case of strong interference where you were flying. There are warnings about compass magnetic interference, etc. And your satellite count goes up and down like crazy, in and out of gps. When you first power up the drone, it takes a compass measurement and determines direction compared to magnetic north. If there is something near the drone at this critical time, when it takes off, it will not know which direction it is facing correctly, and will exhibit all sorts of weird behavior and uncontrolled and uncommanded movement. I would say that this was the cause of the flight, and I'm glad you were able to land it safely. Compass and magnetic interference warnings like the ones on your screen at takeoff and shortly after should always be a sign to immediately land.

You should always try to avoid powering the phantom on and taking off from locations that can have metal interference nearby or underground (such as concrete etc).

 

[alokbhargava]

I noticed that most of the time it was not flying in GPS mode. If that happens, map will not be able to show you the correct position of aircraft as you clearly pointed out that the actual position of aircraft was different than the one shown in maps. This is clearly explainable.

Main concern is why did you lose GPS?

Please analyze if you had GPS locked before you took off. Its not so easy to get GPS lock during moving AC, one got to be lucky to get a lock in the air.

I also see fencing near the take off area, is that a metal fencing and will affect compass orientation and possibly GPS lock?

You are an experience pilot and you can easily analyze the situation.

 

[Snowwolf]

Here is the DAT file
Dropbox - DJI_ASSISTANT_EXPORT_FILE[2017-01-02 19-27-16].DAT

 

[eaglegoaltender]

I had a P4 previous to the p4p and have done 160 full flights with no issues, 140 flights being with the P4 so I am pretty good and check everything before a flight.

Looks like you are not a "newbie" at flying based on the above and your post so I am sure you are well versed as to calibration, location, interferences etc....

Since what you are seeing on the video Vs where you are actually standing and/or where the P4P is actually located are not in-synch............

Is it possibly a compass calibration issue within your iPad (I say this based on your obvious experience with successful numerous previous flights).

EDIT: have you flown this area before with your P4?

 

[Snowwolf]

Can you get the DAT file instead of the BAK file? How to retrieve a .DAT

Just added DAT file to reply to post, hope you can help

 

[F3honda4me]

Just added DAT file to reply to post, hope you can help

Going to eat lunch then I'll take a look. My guess based on your video though is some kind of interference at time of power on.

 

[Snowwolf]

There were a few parked cars around at the time and there is some metal fencing about 25ft away, I have never had any problems before taking off near parked cars and have done a lot of times, that was the first time I had taken off in that area, once the drone is in the air would it not be better that it is away from these metal sources or is it the controller that needs to be away from the metal ?

 

[Snowwolf]

Going to eat lunch then I'll take a look. My guess based on your video though is some kind of interference at time of power on.

While the drone was booting up it did say on the screen to move the drone because of mags, so moved it a few feet then it showed ok to take off, why would it keep losing all satellites when nearly 200 feet in the air ? thanks for the help, much appreciated

 

[alokbhargava]

While the drone was booting up it did say on the screen to move the drone because of mags, so moved it a few feet then it showed ok to take off, why would it keep losing all satellites when nearly 200 feet in the air ? thanks for the help, much appreciated

My point is did it get a home lock before you took off. You are right, once its up in the air, AC will be away from those ground interferences and will have better accessibility to satellites but its difficult to get a GPS lock in a moving aircraft. Also if it does not have GPS, it will keep moving. One affects the other.

 

[F3honda4me]

So, when you power on the drone, the drone determines the direction it is facing using the compass. Once that is established, and the drone takes off, it uses gyros and accelerometers to determine yaw. So, if you have magentic interference when you first power on the drone, once you get clear of that interference the drone is going to act crazy as yours did, because it can't make sense of what it is seeing. If you look at the image, the yaw and magyaw should have nearly identical values (the green and blue lines) but as you can see, they are off from the start and continue to be off throughout the flight most times. (red line is altitude)

By the way, @BudWalker is to thank for this program (datcon and csvview) and I'm using info I saw in another similar post where he talked about this to determine what happened.

 

[F3honda4me]

To me there also appears to be something in the area you were that was interfering with GPS, though it's also possible because of the interference on the ground it caused the entire flight to have issues with GPS lock.

In conclusion, I would never fly in this location again.

 

[JimHarris]

This is scary. I flew racing quads for 2 years before ever buying a phantom. I am glad I have this experience flying with no assists for situations like this. I am glad you got yours back without incident

 

[eaglegoaltender]

that was the first time I had taken off in that area

So it was your first time in that area - hate to ask a seasoned flier, however did you do a calibration or have issues when calibrating?

I ask that only with regard to the erratic flying and control issues - calibration of the Phantom Compass or the IMU has nothing to do with the loss of GPS and Satellites!

I also have calibrated in areas where there were parked vehicles without an issue - likely about 20 or so feet away from them. I have had issues with calibration near wire fencing and metal backstops at baseball fields however.

Loss of GPS and the satellites coming and going is the real issue here - has to be either there is something very strange with the area you are flying (interference) or there is a fault with the GPS module.

 

[Oil hunter1]

Wow I got the same problem two days ago during my first flight of my Mavic Pro suddenly out of control and running on a full throttle and lost gps. I was also lucky as I got it back after trying to increase the altitude my heart was beating I thought my $1500 will be gone


Sent from my iPad using PhantomPilots

 

[F3honda4me]

So it was your first time in that area - hate to ask a seasoned flier, however did you do a calibration or have issues when calibrating?

I ask that only with regard to the erratic flying and control issues - calibration of the Phantom Compass or the IMU has nothing to do with the loss of GPS and Satellites!

I also have calibrated in areas where there were parked vehicles without an issue - likely about 20 or so feet away from them. I have had issues with calibration near wire fencing and metal backstops at baseball fields however.

Loss of GPS and the satellites coming and going is the real issue here - has to be either there is something very strange with the area you are flying (interference) or there is a fault with the GPS module.

You don't need to calibrate anything every time you fly. In fact you shouldn't calibrate anything unless there is a need to. Not even the compass. The compass works differently in the newer drones than previous. You no longer need to calibrate compass just because you fly someplace new.

 

[F3honda4me]

Wow I got the same problem two days ago during my first flight of my Mavic Pro suddenly out of control and running on a full throttle and lost gps. I was also lucky as I got it back after trying to increase the altitude my heart was beating I thought my $1500 will be gone


Sent from my iPad using PhantomPilots

$1500? I thought a replacement mavic drone is around $750? I just ordered a mavic pro for $999 with remote.

 

[eaglegoaltender]

You no longer need to calibrate compass just because you fly someplace new.

Don't think I mentioned calibrating each time you fly somewhere new - only stated the issues I had while calibrating near a wire fence and that was done only to see how it would react.

I calibrated my P3A once about a year and a half ago and have flown it in other locations over a 150km away from that point of calibration without issues - once "home point is established" - you fly.

My P4 I have also only calibrated once and again have flights from numerous new locations without re-calibrating.

Thanks for mentioning it anyway.

 

[Oil hunter1]

$1500? I thought a replacement mavic drone is around $750? I just ordered a mavic pro for $999 with remote.

Yes probably the unit alone i got a full package with 2 extra bat and carry case and some other stuff


Sent from my iPad using PhantomPilots