Flew 830 ft over water and lost signal! Help me figure it out please

[Dragon2650]

Hi All,

Thanks in advance for the time to reply. This morning I went to the beach and flew my MA for some sunrise shots. I was in APAS mode, 18 satellites, formatted the SD card before launch, and I got to 829 feet downrange per the app and completely lost signal in a very abrupt manner.

No weak signal alerts, no choppy video or any other warnings that I noticed. Also, I never regained control or signal with the DJI app. I though the bird was gone and I had a fly away. Then all of the sudden I heard it and it came to home point, but the app never responded when the link was restored. Can anyone help me to figure this out and why it happened so I don't lose my MA? I had a mild heart attack!

Also, another question...how does the MA perform RTH if there is no signal? I did see the red RTH alert pop up and I hit yes, but if the controller sent the RTH signal, how is that possible with no link RF connection?

What is P-GPS vs. Gentle GPS?

MA Ver. 01.00.0400

11m 0.9s Gentle GPS 18satellites 25.3ft N/A 0.9mph 827.4ft 40% 11.084V 3.703V 3.694V 3.687V 0.016V (Downlink Lost HERE)

12m 19.1s Auto Landing 18satellites 71.5ft N/A 0mph 0ft 40% 11.084V 3.703V 3.694V 3.687V 0.016V Downlink Restored (after 1m 18.2s)

Here is the log file: DJI Flight Log Viewer - PhantomHelp.com

Here is what the alert log stated:
## 06:34:42
GEO: You are in a Warning Zone (Class E Airspace). Fly with caution.
## 06:40:15
GEO: You are in a Warning Zone (Class E Airspace). Fly with caution.
## 06:49:28
Current RTH route will pass a no-fly zone. Pay attention to the aircraft's position to avoid RTH failure.
## 06:50:15
Obstacle Avoidance will be disabled in landing.
## 06:50:26
Obstacle Avoidance will be disabled in landing.
## 06:52:57
GEO: You are in a Warning Zone (Class E Airspace). Fly with caution.
## 06:54:53
GEO: You are in a Warning Zone (Class E Airspace). Fly with caution.
## 06:57:51
GEO: You are in a Warning Zone (Class E Airspace). Fly with caution.
## 07:01:41
Obstacle Avoidance will be disabled in landing.
## 07:01:52
Obstacle Avoidance will be disabled in landing.

 

[BuffaloAir]

Good question, I'd enjoy hearing a good answer to this inquiry. I'm really new with the Mavic Air, too and the approach I've taken is accept this can happen anytime and learn the appropriate emergency procedure to try and bring it home. The most significant step I've taken is never fly out of Line Of Vision. Hard to follow that advice sometimes, though.

 

[Dragon2650]

@BuffaloAir I never went out of VLOS. The only thing I can think of is there may have been wi-fi interference from cell phones on the pier. I know the restaurant has wi-fi also, but I was a good 100 feet from the pier at launch.

 

[Prismatic]

@BuffaloAirThe video of the flight is here: ...

YouTube does not serve a video on that link: Video not available

 

[colinfowler]

The aircraft holds the RTH settings you selected, so on disconnect or lose of signal it will RTH

 

[Dragon2650]

This is the video I took when I lost all communications. You can see I was not that far from the beach and not that close to the pier.

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[Dragon2650]

The aircraft holds the RTH settings you selected, so on disconnect or lose of signal it will RTH

I understand that part, I just don't understand the Loss of Downlink for no apparent reason.

 

[BuffaloAir]

This is what concerns us all, we're flying along fat, dumb and happy and the drone suddenly does what it wants to do. It certainly reduces your security in doing more than just flying over the field in the park next door.

 

[Dragon2650]

This is what concerns us all, we're flying along fat, dumb and happy and the drone suddenly does what it wants to do. It certainly reduces your security in doing more than just flying over the field in the park next door.

Ain't THAT the truth!

 

[Tanushiheadbash]

I had something similar last week. I flew my MA over a river and was only about 90metres away so perfectly visible, when suddenly and with no intermittency first, I lost the video feed and received the Lost Signal warning. What was odd was the drone did not immediately RTH though I had plenty of GPS and ensured it had registered the home point. In fact, it was still responding to controls, as I was able to ascend to see if I could improve the reception but it was no good. I then used RTH to get it back.
A second sortie out 120 degrees in the other direction had a similar issue. I thought maybe I had a fault and the drone reported it needed a f/w update half way through the flight, but after checking it all out the next morning, refreshing all firmware on both MA and R/C via DJI Assisatant I flew it locally and had no issues out to 300mtrs. I can only assume it was some localised interference issue though it wasn't obvious on the RF wifi signal part of the app.

 

[Dragon2650]

I had something similar last week. I flew my MA over a river and was only about 90metres away so perfectly visible, when suddenly and with no intermittency first, I lost the video feed and received the Lost Signal warning. What was odd was the drone did not immediately RTH though I had plenty of GPS and ensured it had registered the home point. In fact, it was still responding to controls, as I was able to ascend to see if I could improve the reception but it was no good. I then used RTH to get it back.
A second sortie out 120 degrees in the other direction had a similar issue. I thought maybe I had a fault and the drone reported it needed a f/w update half way through the flight, but after checking it all out the next morning, refreshing all firmware on both MA and R/C via DJI Assisatant I flew it locally and had no issues out to 300mtrs. I can only assume it was some localised interference issue though it wasn't obvious on the RF wifi signal part of the app.

Wow! The exact scenario I had. I also re-loaded the MA firmware but this time through the DJI Assistant program in my PC, just to be sure since I have read a few threads about this issue, and I reset all settings to factory default. I have not yet had the time to fly but will do so soon, hopefully later today. If you read the threads online, a lot of folks say it is the firmware, but I don't know. I have also read a few threads where the MA owner's have stated that they have had bad units wherein the wi-fi signal is not good and have returned the unit for replacement with no further issues. I have not had a chance to verify this which I should have done by testing prior to reloading the firmware, but I do have a golf course close by where I can fly out to 400 yards and see if I have LOS (Loss of Signal). At least if I lose signal it won't fall into the water, but it may fly away (Hopefully not)! I did however speak to a friend who fly's in the same area regularly and he stated that he has had connection issues with a Phantom 4 at the same location, so hopefully it is a localized issue. I don't know of anywhere I can fly close to my home where I can test the extreme range limits. I guess a road trip is in order!

 

[BuffaloAir]

Guess what, just took the MA out for a short flight above my house and about 500 distance and max alt 393 ft. Then got the red message "Aircraft lost connection" I answered okay to RTH, then I exited the flight screen went back to try to connect to the aircraft, no luck, meanwhile MA is returning. I gained no control of the aircraft after two retries to connect. It landed at home. Thankfully and oh boy, that's good. This is extremely limiting, I have my 107 commercial rating and am freelance photographer for a local newspaper with very active website. I can't afford for the drone to not perform. It's way too risky for me and the paper.

What are our options when we get the red message "Aircraft lost connection"? I thought trying to establish reconnection might work. What are our options, what are the procedures to be followed to regain control?

 

[BuffaloAir]

It appears the emergency procedures for a failed connection are that the aircraft will RTH and behave in the following manner. Not much we can do as pilot.
RTH Procedure (I would assume the FailSafe Procedure would be applicable in a Aircraft Lost Connection situation.

Failsafe RTH

The Forward Vision System allows the aircraft to create a real-time map of its fight route as it flies. If the Home Point was successfully recorded and the compass is functioning normally, Failsafe RTH will be automatically activated if the remote control signal is lost for a speci ed amount of time (three seconds when using the remote controller and 20 seconds when ying with a mobile device).

When Failsafe RTH is activated the aircraft starts to retrace its original ight route home. If the wireless control signal is re-established within 60 seconds of Failsafe RTH being activated, the aircraft hovers at its present location for 10 seconds and waits for pilot commands. The user may tap in the DJI GO 4 app or press the RTH button on the remote controller to cancel Failsafe RTH and retake control. If no pilot command is given the aircraft ies to the Home Point in a straight line. If the wireless control signal is still lost 60 seconds after Failsafe RTH was activated the aircraft stops retracing its original flight route and flies to Home Point in a straight line.


Smart RTH, Low Battery RTH, and Failsafe RTH follow this procedure:

1. The aircraft adjusts its orientation.

2. a. If the aircraft is further than 20 m from the Home Point it ascends to the pre-set RTH attitude and

then ies to the Home Point.

b. If the aircraft is between 5 m and 20 m from the Home Point it ies to the Home Point at the

current altitude, unless the current altitude is less than 2.5 m, in which case the aircraft ascends

to 2.5 m and then ies to the Home Point.

c. If the aircraft is less than 5 m from the Home Point it lands immediately.

3. The aircraft lands and stops its motors once it reaches the Home Point.

What I would like to see is
If aircraft looses connection do this . . .

 

[Kris.]

Unfortunately it's a common problem with latest app/firmware. It's only video signal/feed that is lost, not the controls. That's wht RTH does not kick in. Scary and annoying but actually no big risk, if you don't have to use visual info in order to navigate home. Nothing to do from a pilot side, unfortunayely :-(.

 

[BuffaloAir]

Thanks Kris, in this case RTH did kick in. What I'm looking for are the procedures to follow when we see that message "Aircraft lost connection". Should I exit the flight screen go back to the "Enter Device" screen and attempt to reconnect? Should I cancel RTH and wait for it to reconnect? I almost always use the "Wired Connection" option. Should I switch to "Wi-Fi connection" in a situation when I lose Wired connection. It only has happened twice to me in 12 hours 75 minutes of flight time on the MA. Hard to experiment. Shouldn't the bright guys at DJI have a procedure?

 

[Gmgfarrand]

I had something similar happen as I was going around a water tower, as I got closer, saw all kinds of cell/radio antennas, said "oh ****" and yep, BOOM.
No connection, signal lost.
It came right back to me.

 

[Mossiback]

...What are our options when we get the red message "Aircraft lost connection"? I thought trying to establish reconnection might work. What are our options, what are the procedures to be followed to regain control?

The red "Aircraft lost connection" means the connection between the AC and RC was lost. The RC and Go 4 are still connected and working. Your only options are to hope that RTH is set up and functioning correctly or turn your RC off and back on in hopes of reestablishing a connection.

 

[mad monkey]

Once back in range the connectivity will reestablish and you can cancel rth and keep going if you please. If you're like me and this happens you'll need a. Break anyways to change your shorts

 

[Dragon2650]

On my excursion the MA seemingly never regained the connection.

 

[BuffaloAir]

The red "Aircraft lost connection" means the connection between the AC and RC was lost. The RC and Go 4 are still connected and working. Your only options are to hope that RTH is set up and functioning correctly or turn your RC off and back on in hopes of reestablishing a connection.

Thank you. That helps settle one emergency procedure.