Moral of the story !!!! learn to fly (and control your Drone) in Atti mode !!!! (its part of the RePL course here in Australia!) and it will hold you in good stead if this happens again !
Mavic 2 Pro Crash out of Control
- Thread starter AtortPhotography
- Start date
It is so crazy to fly in between the buildings because of the drafts and winds and in ATTI mode was just like a bat out of hell. The thing I don't get or understand is that it was picking up momentum it seemed it wasn't to me like simply having to control the left and right movements it felt like it kept ramping up momentum. Sucks!
Moral of the story too is flying in the city blows. There is so much S#$t that can go wrong with interference and always just seems like such a hassle. Can't wait to get back to Hawai'i and never see a city again. I am training with an FPV simulator now and FPV drone is next purchase so that I hope will help with ATTI flying.
Not A Speck Of Cereal
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No, I've flown between sky scrapers just fine. But I learned to do it only in ATTI mode, or at least keep my finger on the switch in case things seem to start going whacky.
Of course, you wouldn't want to do this in high winds, but that would be true anywhere obstacles are, such as around trees.
Chris
The moral of the story is what "Drone" pilots have been saying for years...DO NOT learn to fly on GPS drones...while yes "most" times you can. The more advanced pilot will practice for months on a simple $30 to $50 drone and gain skills to fly in wind with no hold, at any angle of flight. Those who wish to skip the learning are the ones who forfeit their money for the most part. It simply isn't the aircraft manufactures job to teach you to fly...use due diligence and learn or not...it is just that simple.
I spent months learning on a FP heli, then to a CP Heli...thought I had it down and moved to a crappy hubsan $50 drone and learned all over again..I practiced inside with a ceiling fan and a box fan blowing that sucker all around...that will take it out of you...trust me...but eventually it just clicks in your mind and your fingers do the walking as they say...
I spent months learning on a FP heli, then to a CP Heli...thought I had it down and moved to a crappy hubsan $50 drone and learned all over again..I practiced inside with a ceiling fan and a box fan blowing that sucker all around...that will take it out of you...trust me...but eventually it just clicks in your mind and your fingers do the walking as they say...
As Meta4 has stated, interference does not and cannot cause the aircraft to go out of control.
Radio receivers operate on specific frequencies and the data carried is digital. Even if any kind of transmitter was working on the exact same frequency it cannot control or cause loss of control of the aircraft. Even if the radio transmission power was high enough at any other frequency, the front end of the receiver filters it out. Only very high levels of signal can swamp the receiver at which point the onboard processing will not be receiving valid data and it will simply ignore it.
Onboard processing on the aircraft error checks received data and only valid data and data from its sensors is used to control the aircraft. And it is the same with the GPS data. The GPS signals carry very specific digital data and the decoding of that data is tested against a known published format. If the signal from one or more satellites is weak or containing errors those satellites will be ignored. When a GPS device shows the number of satellites locked it means it is receiving valid data from them.
In the OPs case the logs show onboard processing was seeing too few locked satellites for it to maintain its position sufficiently. At the same time it was receiving validated commands from the OPs RC (and from nowhere else) and was acting upon those commands to action the movement of the aircraft.
The ability of digital electronics to validate received data is what allows your WiFi to work, Bluetooth, digital TV and Radio, DVDs and CDs to play without visible or audible errors, mobile phones and every bit of data on the Internet. It’s the reason NASA can send and receive error free data between this planet and spacecraft from every other planet in our solar system and even beyond despite massive levels of radiation from the sun and exploding stars.
So please, no more misinformation about traffic/stop lights, police and fire crew traffic controls, too close to cell towers or satellite dishes, powerlines and all the other theories and guesses. The majority of crashes are a direct result of pilot error, lack of experience or lack of knowledge about the aircraft and how it works.
Radio receivers operate on specific frequencies and the data carried is digital. Even if any kind of transmitter was working on the exact same frequency it cannot control or cause loss of control of the aircraft. Even if the radio transmission power was high enough at any other frequency, the front end of the receiver filters it out. Only very high levels of signal can swamp the receiver at which point the onboard processing will not be receiving valid data and it will simply ignore it.
Onboard processing on the aircraft error checks received data and only valid data and data from its sensors is used to control the aircraft. And it is the same with the GPS data. The GPS signals carry very specific digital data and the decoding of that data is tested against a known published format. If the signal from one or more satellites is weak or containing errors those satellites will be ignored. When a GPS device shows the number of satellites locked it means it is receiving valid data from them.
In the OPs case the logs show onboard processing was seeing too few locked satellites for it to maintain its position sufficiently. At the same time it was receiving validated commands from the OPs RC (and from nowhere else) and was acting upon those commands to action the movement of the aircraft.
The ability of digital electronics to validate received data is what allows your WiFi to work, Bluetooth, digital TV and Radio, DVDs and CDs to play without visible or audible errors, mobile phones and every bit of data on the Internet. It’s the reason NASA can send and receive error free data between this planet and spacecraft from every other planet in our solar system and even beyond despite massive levels of radiation from the sun and exploding stars.
So please, no more misinformation about traffic/stop lights, police and fire crew traffic controls, too close to cell towers or satellite dishes, powerlines and all the other theories and guesses. The majority of crashes are a direct result of pilot error, lack of experience or lack of knowledge about the aircraft and how it works.
It picked up momemtum to fly backward as seen near the end of the footage because full backward elevator control was applied and held for as long as 2 seconds. Such movement has nothing to do with ATTI mode.
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The fact is the craft went into full-blown ATTI mode for just one second. Furthermore, there were on average 8.5 satellites seen so it didn't look too bad so I can understand why you had the impression that things were OK.
Unfortunately, due to blockage by buildings in the immediate vincinity, the distribution of visible satellites in the sky was not even enough to allow reliable positioning to be achieved. As the result the flight controller used mainly the IMU for positioning which is not as precise so the craft's response to control inputs became not as solid as it used to be.
What is the minimum amount of satellites you should have locked to fly confidently without having to be concerned about it doing into ATTI mode?
If you are flying where your drone has a clear, unobstructed skyview, you will always have many more sats than needed.
Two questions....first is there ever a safe way to fly in between tall buildings then in the city and how do you even practice flying a Mavic 2 Pro in ATTI mode?! I mean on my Phantom 4 Pro's you obviously have that switch to fly, but again the behavior with the M2Pro was far different from when I flew my Phantoms in ATTI mode in Hawaii. I was usually over an open ocean though so there's that.
Flying in atti can be quite safe (with experience), but flying in atti mode close to obstacles is risky, and wind would make it more risky.
There shouldn't be much difference in their behaviour in atti mode, so the Phantom would be a good way to gain experience.
Generally, 8 or more. This is typical of deep narrow canyons.
In open area I typically get 20-24 satelllites.
If you are planning to fly in urban canyons or similar environments where obstacles block a large part of the sky, there is no number that would give that confidence.
DJI won't allow the drone into P-GPS mode with less than 6 sats, but the number needed could be more as besides the number of sats, there is also a requirement for a good geometrical spread of sats to get good GPS location data.
Not A Speck Of Cereal
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It's not necessarily DJI sanctioned, but it is also not quite an actual hack. Using DJI Assistant in debug mode, you can change a value to over-ride one of your switches. For instance, if you don't really need Sport mode, you can program your controller to put the aircraft into ATTI mode when you switch to the S position.
There's a few topics on these boards. Here's a couple of topic links, plus a video link on the process:
Mavic 2 Atti mode
I haven't seen anyone else mention it so, just in case anyone is interested, I can confirm that it is possible to switch the M2P into ATTI mode by changing the mapping on the flight mode switch using the same DJI Assistant functionality as with the MP. I altered the Sport mode setting (8) to...
mavicpilots.com
Atti mode Mavic 2 pro
Is it possible / or wise to alter the software to allow flight in atti mode. Needed for me to train for my RePl.
mavicpilots.com
Those threads would be a good place to ask additional questions, if things don't go right or you're not sure which script to edit (you need to change one thing in a text file to get this to work).
Chris
It's not the satellite count that matters, it's the confidence that Flight Controller has in it's location solution. A low confidence means that the FC can't depend on it's location solution and a switch to ATTI mode occurs. Low confidence is caused by other problems besides a low satellite count, in particular suspected compass data. I.e. the satellite count could be 20 and the FC will switch to ATTI mode because of a problem with the compass data.
Much better to check the FC's confidence in the location solution which is presented as the navHealth (aka gpsLevel). A confidence of 4 or 5 (out of 5) is necessary to avoid ATTI mode. NavHealth is shown on both the RC and the Go or Fly App as a bar graph. Here is the RC presentation
Thanks.It's not necessarily DJI sanctioned, but it is also not quite an actual hack. Using DJI Assistant in debug mode, you can change a value to over-ride one of your switches. For instance, if you don't really need Sport mode, you can program your controller to put the aircraft into ATTI mode when you switch to the S position.
There's a few topics on these boards. Here's a couple of topic links, plus a video link on the process:
Mavic 2 Atti mode
I haven't seen anyone else mention it so, just in case anyone is interested, I can confirm that it is possible to switch the M2P into ATTI mode by changing the mapping on the flight mode switch using the same DJI Assistant functionality as with the MP. I altered the Sport mode setting (8) to...Atti mode Mavic 2 pro
Is it possible / or wise to alter the software to allow flight in atti mode. Needed for me to train for my RePl.
Those threads would be a good place to ask additional questions, if things don't go right or you're not sure which script to edit (you need to change one thing in a text file to get this to work).
Chris
I bought a DJI FPV controller and have been using Liftoff to practice. Stinks though that happened.The moral of the story is what "Drone" pilots have been saying for years...DO NOT learn to fly on GPS drones...while yes "most" times you can. The more advanced pilot will practice for months on a simple $30 to $50 drone and gain skills to fly in wind with no hold, at any angle of flight. Those who wish to skip the learning are the ones who forfeit their money for the most part. It simply isn't the aircraft manufactures job to teach you to fly...use due diligence and learn or not...it is just that simple.
I spent months learning on a FP heli, then to a CP Heli...thought I had it down and moved to a crappy hubsan $50 drone and learned all over again..I practiced inside with a ceiling fan and a box fan blowing that sucker all around...that will take it out of you...trust me...but eventually it just clicks in your mind and your fingers do the walking as they say...
So basically the remote control connection strength correct? I have a smart controller and then use the Fly App for the other drones. So you really think this is more crucial than the amount of satellites connected?
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