Primary Cause of Fly Aways?

[cstout]

I've been reading and educating myself as much as possible on fly aways. There are so many reports and investigations of how and why posted here and elsewhere and I wanted to ask. It appears that in a lot of cases of fly aways the pilot was operating in Atti mode either intentionally or accidentally. Is this the primary cause of fly aways? From what I'm seeing it's either a complete loss of GPS connection or it was flown in Atti mode.

 

[Jayfdee]

I think most fly aways these days are pilot error, as you say accidental atti mode blown away by the wind, not calibrating compass, somehow getting the wrong home point,getting disorientated and pushing the stick the wrong way I have always had good gps with my p4 and Glonass, but my p2 was problematic.

 

[alokbhargava]

I see many reporting GPS loss but I wonder if that's really true or is it incorrectly reported by DJI Go app. For me gps has been so reliable in open fields or high in the sky, I really do not know what causes many to report gps failures.

I can understand wrong compass calibration leading to trouble at site. To test this I stopped recalibrating compass for months and travelled distances but noticed absolutely no problem.

My feeling is that once you have a crash, even minor, there are chances internal hardware gets loosened/ shaken and lead to problem or unexpected behavior and surprise us. Opening shell is not an easy task for checking the connections and carrying out other maintenance tasks. Even though electronics could be reliable but settling of dusts with moisture over components, loosening of connections due to hits etc could pose risks to our investment. Phantoms should be designed for easy maintenance.

These are my two cents.


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[Mark The Droner]

I've never seen one in real life. I've read about them. I think most legitimate flyaways are from compass errors or GPS errors. But many of those can be blamed on the pilots, I suspect.

 

[John Locke]

If you have a lightbridge DJI drone, flyaways are very rare, especially if you have a P4 or later with dual compass and dual IMU. If you have lost the video connection, and your craft goes into ATTI mode (because of loss of GPS or a magnetic anomaly to cause a compass error), and you have no VLOS, THATS NOT GOOD.....you are in trouble, especially if the wind is blowing the craft away from you. This is a good reason to try and fly upwind if you can, but I never plan my route based on wind. It's also a good reason to fly with VLOS, in case you do have one of these rare times where the craft goes into ATTI.

In 18mos of flying Lightbridge DJI drones, I've had two instances of my P3P craft going into ATTI. Once at the beach for a compass error, I don't know why. The second time is when I lost GPS when I was flying under a cement bridge (my oversight). Fortunately both times I had VLOS and easily flew the craft to land safely. My P4 has never gone into ATTI in the 9mos I've had it, not even a hint of GPS or compass issues.

In the past when DJI used WiFi for communications there were more frequent instances of flyaways. I'm not talking about drifting away with the wind in ATTI mode, I'm talking about literally flying away as if someone else was controlling it. The advent of Lightbridge, starting with Phantom 3 Advanced and Pro, this kind of flyaway virtually never happens anymore. This is one of the key reasons I'll never buy a drone that uses old school WiFi for communications, unless it's a $50 trainer for newbies.

 

[F3honda4me]

I'd say primary cause is pilot error.

 

[cstout]

If you have a lightbridge DJI drone, flyaways are very rare, especially if you have a P4 or later with dual compass and dual IMU. If you have lost the video connection, and your craft goes into ATTI mode (because of loss of GPS or a magnetic anomaly to cause a compass error), and you have no VLOS, THATS NOT GOOD.....you are in trouble, especially if the wind is blowing the craft away from you. This is a good reason to try and fly upwind if you can, but I never plan my route based on wind. It's also a good reason to fly with VLOS, in case you do have one of these rare times where the craft goes into ATTI.

In 18mos of flying Lightbridge DJI drones, I've had two instance of my P3P craft going into ATTI. Once at the beach for a compass error, I don't know why. The second time is when I lost GPS when I was flying under a cement bridge (my oversight). Fortunately both times I had VLOS and easily flew the craft to land safely. My P4 has never gone into ATTI in the 9mos I've had it, not even a hint of GPS or compass issues.

In the past when DJI used WiFi for communications there were more frequent instances of flyaways. I'm not talking about drifting away with the wind in ATTI mode, I'm talking about literally flying away as if someone else was controlling it. The advent of Lightbridge, starting with Phantom 3 Advanced and Pro, this kind of flyaway virtually never happens anymore. This is one of the key reasons I'll never buy a drone that uses old school WiFi for communications, unless it's a $50 trainer for newbies.

This is hugely reassuring. Thank you for sharing.

 

[msinger]

It appears that in a lot of cases of fly aways the pilot was operating in Atti mode either intentionally or accidentally. Is this the primary cause of fly aways?

I personally reviewed almost all of the flyaway cases posted in this forum. I don't keep a tally of them, but from memory I'd say the causes are as follows (in this order):

1) Pilot flies behind an obstacle or out of remote controller range and the Phantom:

A) Crashes because RTH is not set to the proper altitude
B) Auto lands in an unknown location either because the battery is too low or the remote controller signal is lost​

2) Pilot is not able to control the Phantom due to an improper compass calibration or launching near magnetic metal objects
3) Pilot does not understand how to control the Phantom when it auto changes to ATTI mode

 

[AlecW]

I've searched for and read a lot of flyaway threads. The vast majority seem to be pilot errors even though the pilot often disagrees with the log reading experts . Some are entertaining to read, especially when an arrogant person crashes and keeps telling everyone he's some type of engineering expert, blah, blah


Edit: You can learn from the crash threads, at least I have.

 

[Tenly]

2) Pilot is not able to control the Phantom due to an improper compass calibration or launching near magnetic metal objects

I think this one is most likely to affect people who calibrate before every flight (like I've seen some people recommend). But once someone has done a good calibration away from any interference - the compass should remain calibrated correctly and shouldn't need to be done again - and if it does - the Phantom will ask for it.

Even taking off from an area with metal or magnetic interference shouldn't cause a problem once airborne and away from the interference - but recalibrating it while in an area with interference might make it work properly while still IN that area - but as soon as flying away from the interference, the calibration would be way off and likely cause problems.

I only ever calibrate my compass when the app asks me to (about 3 times - usually after a major firmware upgrade) and that has been working fine for me and my P3P for 18 months now. Likewise with the IMU - I've only calibrated once in 18 months and have had no problems.




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[Fred Guernsey]

Please see my post today:-
Going in circles...
I think I have touched on this topic before - even with a good calibration, are you saying that you should not launch anywhere near metal

 

[F3honda4me]

Please see my post today:-
Going in circles...
I think I have touched on this topic before - even with a good calibration, are you saying that you should not launch anywhere near metal

Correct.

 

[Meta4]

I think I have touched on this topic before - even with a good calibration, are you saying that you should not launch anywhere near metal

Metal is not a problem .... unless the metal is iron or steel.
You can take off from aluminium, copper, lead, brass etc.
Just stay away from iron and steel and electromagnetic sources (live cables etc).

 

[Meta4]

I personally reviewed almost all of the flyaway cases posted in this forum. I don't keep a tally of them, but from memory I'd say the causes are as follows (in this order):

1) Pilot flies behind an obstacle or out of remote controller range and the Phantom:

A) Crashes because RTH is not set to the proper altitude
B) Auto lands in an unknown location either because the battery is too low or the remote controller signal is lost​

2) Pilot is not able to control the Phantom due to an improper compass calibration or launching near magnetic metal objects
3) Pilot does not understand how to control the Phantom when it auto changes to ATTI mode

The other popular choice is flying away downwind in a strong wind (often up high) and complaining that the Phantom flew away when the wind was too strong for RTH to fight it.

 

[Meta4]

I've been reading and educating myself as much as possible on fly aways. There are so many reports and investigations of how and why posted here and elsewhere and I wanted to ask. It appears that in a lot of cases of fly aways the pilot was operating in Atti mode either intentionally or accidentally. Is this the primary cause of fly aways? From what I'm seeing it's either a complete loss of GPS connection or it was flown in Atti mode.

If you mean real flyaways, these are much too rare to be able to give a common cause.
Flyaway is mostly a euphemism for ... I lost my Phantom and don't know why.
Since the P3 came out, the Go app records flight data which can be examined to find out what really happened in a lost phantom incident.
Flight data shows most incidents are directly caused by the owners, confusion, disorientation and mistakes.

 

[cstout]

My hope in posting was that it would lead to the exact type of conversation that's taken place here today. Shedding light on a topic with some widespread confusion. It's been a really worthwhile discussion that I hope helps others understand that there was originally a real fly away issue but since the P3 it's been the pilot making a mistake and then labeling the issue improperly.


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[Farkle1]

Hopefully not too much of a topic deviation? but if your flying with the Litchi app does it offer the same level of flight data recording? Obviously an important
element if a "fly away" occurs... I'm a newbie to this fun, please cut me some slack!

 

[msinger]

if your flying with the Litchi app does it offer the same level of flight data recording?

There are two flight logs. The DAT flight log on the Phantom will be the same no matter which app you use. The flight log stored on your mobile device is created by the app you're using. The Litchi CSV flight log doesn't contain as much information as the DJI GO TXT flight log.