Bad luck, bad drone, or bad pilot

[Meta4]

NFZ's won't disable the drone in flight. At best it will geofence your drone. At worst, you won't even be able to spin up the propellers.
I haven't looked at your flight logs, but if you are IN an NFZ's or TFR's, the Go(4) app won't even allow the motors to spin up. So I would dismiss the TFR theory.

In cases where flyers launch before acquiring GPS location data and are flying in an NFZ or TFR area before the drone knows it.
When the drone gets GPS location data, it autolands.

I'm going to guess erroneous, debilitating WiFi interference was the cause of your crash. It's been my profound experience that it is possible for a DJI drone to interpret some WiFi interference as erroneous commands. I crashed a drone late last year because I didn't follow my own WiFi protocols. I also ignored erroneous drone behavior - all because I was in a hurry.

Interference at high levels, can make the video transmission or joystick response a little glitchy.
In worst case, it could swamp the control signal, triggering Failsafe RTH.
But it can't interfere with the controls, giving spurious control inputs or crash the drone.

 

[Harleydude]

In cases where flyers launch before acquiring GPS location data and are flying in an NFZ or TFR area before the drone knows it.
When the drone gets GPS location data, it autolands.

Correct. But that's not a crash. An autoland can be circumvented via the throttle to at least get the drone to where you want it to land. I've been in an autoland situation before. The OP said his crashed, which is way different from autolanding.

Interference at high levels, can make the video transmission or joystick response a little glitchy.
In worst case, it could swamp the control signal, triggering Failsafe RTH.
But it can't interfere with the controls, giving spurious control inputs or crash the drone.

I disagree. I'm not the only person who has experienced unexplained, sporadic drone behavior. Unlike most pilots, my drones are hacked and I have years of experience and years of eventless flying under my belt. Before my Inspire 1 came crashing to the ground, I experienced TWO dramatic direction change events that, to my great discredit, I ignored. TWICE my Inspire 1 tried to warn me of overwhelming WiFi via sporadic behavior and twice I ignored it. Subsequent on-site forensics revealed WiFi interference on all 32 channels, ranging from MASSIVE interference (enough to render channels completely useless) on at least 28 of the channels, and a lesser level of interference on the remaining 4 channels, but interference none-the-less. Up until that jobsite, I have always been able to find at least 4 clear channels. On this jobsite there were zero clear channels, only some channels with less interference than others.

If you want to experience this erroneous behavior first hand, fly right up to 40-watt a cell tower.

RTH is LOSS of signal. Sporadic behavior is *overwhelming erroneous* signal. Two different symptoms for two different anomalies.

D

 

[bsartist]

Correct. But that's not a crash. An autoland can be circumvented via the throttle to at least get the drone to where you want it to land. I've been in an autoland situation before. The OP said his crashed, which is way different from autolanding.












D

During my one experience where my P4P suddenly decided it entered an NFZ on the return trip home, throttle inputs were totally ignored when it initiated auto land. I could fly forward but unlike low batt auto land, the NFZ one will not allow throttle to keep it aloft. But, true, it did not crash. Just persistently descended.

 

[Harleydude]

During my one experience where my P4P suddenly decided it entered an NFZ on the return trip home, throttle inputs were totally ignored when it initiated auto land. I could fly forward but unlike low batt auto land, the NFZ one will not allow throttle to keep it aloft. But, true, it did not crash. Just persistently descended.

ATTI Mode is your panic button. Toss any drone into ATTI mode and that will arrest the RTH. This assumes, of course, that you have a connection to the drone. The very thing that makes RTH useful is the ability to regain control of the drone as it draws nearer to the Home Point. And the best, quickest way to arrest ANY smart mode is by tossing the drone into ATTI mode.

D

 

[Meta4]

ATTI Mode is your panic button. Toss any drone into ATTI mode and that will arrest the RTH. This assumes, of course, that you have a connection to the drone. The very thing that makes RTH useful is the ability to regain control of the drone as it draws nearer to the Home Point. And the best, quickest way to arrest ANY smart mode is by tossing the drone into ATTI mode.

If the drone was reacting to a mapped NFZ, it's unlikely that atti mode would make any difference.
Switch to atti mode and the drone doesn't use GPS for horizontal position holding, but the GPS receiver is not switched off.
The drone continues using the GPS for position data so it would still believe it was in the NFZ.

 

[bsartist]

ATTI Mode is your panic button. Toss any drone into ATTI mode and that will arrest the RTH. This assumes, of course, that you have a connection to the drone. The very thing that makes RTH useful is the ability to regain control of the drone as it draws nearer to the Home Point. And the best, quickest way to arrest ANY smart mode is by tossing the drone into ATTI mode.

D

It wasn’t RTH. I was flying it home within range. It gave a warning suddenly about being in an NFZ and it started to land. Pushing the throttle up had no effect. I tried to push forward. That worked but it was on a persistent glide slope down and eventually into a tree.

 

[bsartist]

If the drone was reacting to a mapped NFZ, it's unlikely that atti mode would make any difference.
Switch to atti mode and the drone doesn't use GPS for horizontal position holding, but the GPS receiver is not switched off.
The drone continues using the GPS for position data so it would still believe it was in the NFZ.

As an aside, this is a flight path I’ve taken many many times. There is an “unpaved airport” in the lake - a seaplane base which isn’t active but I guess it’s charted. It’s never been a problem. Ever. Before or since. In fact I was almost home and well away from the lake when this kicked in.

Luckily it tumbled through the tree and landed in snow unharmed.

 

[Harleydude]

If the drone was reacting to a mapped NFZ, it's unlikely that atti mode would make any difference.

Tossing the drone into ATTI mode immediately dumps all waypoint function. This works 100% of the time. I concede that ATTI mode will NOT allow you to proceed into the NFZ. But to say ATTI mode "unlikely...make any difference" is incorrect. It WOULD make a difference in how the drone behaves.

Switch to atti mode and the drone doesn't use GPS for horizontal position holding, but the GPS receiver is not switched off.

Correct. ATTI mode doesn't "dump the satellites." It merely tells the drone to IGNORE the satellites.

The drone continues using the GPS for position data so it would still believe it was in the NFZ.

Correct again....sort of. As I stated above, you can't plow into an NFZ in ATTI mode. True. But you CAN arrest a forced landing. THAT said, there are a couple reasons why a drone would land itself. NFZ breech is just one of them.

This is based on my personal experience with both the Inspire 1 and Phantom 4 Pro all running legacy firmware. So I can only speak for those drones. So...unless DJI changed something in their firmware...

D

 

[Harleydude]

It wasn’t RTH. I was flying it home within range. It gave a warning suddenly about being in an NFZ and it started to land.

So you were able to fly OUT THROUGH an NFZ, but not able to take that same path BACK through the NFZ??? This makes no sense.

Pushing the throttle up had no effect. I tried to push forward. That worked but it was on a persistent glide slope down and eventually into a tree.

Did you try putting your drone in ATTI mode? Forced landing is a "smart function." It's been my profound experience that ATTI mode disables all smart functions.

Another thing that bother me about this post is I have tried to fly my Inspire 1 into an NFZ before and the drone just stops dead in its tracks. It never tried to land. I have also flown my P4P within 1.5 miles of a Class D airport for a mapping project. Though I was not able to engage any smart functions, I WAS able to fly the mission manually. Neither drone ever tried to land itself. So I can't help but think something else may have been going on.

Thoughts?

D

 

[Pygar70]

ATTI Mode is your panic button. Toss any drone into ATTI mode and that will arrest the RTH. This assumes, of course, that you have a connection to the drone. The very thing that makes RTH useful is the ability to regain control of the drone as it draws nearer to the Home Point. And the best, quickest way to arrest ANY smart mode is by tossing the drone into ATTI mode.

D

I thought RTH still worked in ATTI mode. Are you saying that's not the case?

 

[Harleydude]

I thought RTH still worked in ATTI mode. Are you saying that's not the case?

Correct. But I have to qualify that statement. If you fire up your drone and controller in ATTI mode, your drone will default to GPS lock. So you have to ENGAGE ATTI mode (not BE in ATTI mode from the get go). If you started off in ATTI mode, you can toggle to GPS mode and then BACK to ATTI mode and this will disengage any smart flight function, which includes RTH. Tossing in ATTI mode will disengage RTH 100% of the time.

I have tested this on:

Phantom 4 Pro
Mavic Pro
Inspire 1 Pro
M600 Pro
M300 RTK

D

 

[Pygar70]

Correct. But I have to qualify that statement. If you fire up your drone and controller in ATTI mode, your drone will default to GPS lock. So you have to ENGAGE ATTI mode (not BE in ATTI mode from the get go). If you started off in ATTI mode, you can toggle to GPS mode and then BACK to ATTI mode and this will disengage any smart flight function, which includes RTH. Tossing in ATTI mode will disengage RTH 100% of the time.

I have tested this on:

Phantom 4 Pro
Mavic Pro
Inspire 1 Pro
M600 Pro
M300 RTK

D

Okay, you're saying that engaging ATTI mode during a RTH will stop the RTH. I guess you'd only be doing that if you had already tried to disengage RTH by pressing the RTH button, right?
I presume you can still be in ATTI mode and have RTH initiate, either manually or automatically?

 

[Meta4]

I thought RTH still worked in ATTI mode. Are you saying that's not the case?

RTH will work if GPS is available.
GPS is still available if you switch to atti mode,.
GPS is not available if the drone is in atti mode because you've lost GPS signal.

 

[Meta4]

So you were able to fly OUT THROUGH an NFZ, but not able to take that same path BACK through the NFZ??? This makes no sense.

The usual explanation for that situation is that the drone was launched in, or flew into the NFZ before GPS reception was established.

Did you try putting your drone in ATTI mode? Forced landing is a "smart function." It's been my profound experience that ATTI mode disables all smart functions.

Forced landing isn't a particularly smart function like automated RTH or waypoints.
I haven't tried it, but would be very surprised if flicking to atti mode made any difference to a forced landing in an NFZ

 

[Harleydude]

Okay, you're saying that engaging ATTI mode during a RTH will stop the RTH.

Correct.

I guess you'd only be doing that if you had already tried to disengage RTH by pressing the RTH button, right?

I go directly to the ATTI switch. That is my "panic button." When s*** is going South, ATTI mode can save your bacon. So I don't mess around with "Cancel RTH." I go straight for the jugular.

I presume you can still be in ATTI mode and have RTH initiate, either manually or automatically?

Yes. ONLY if you power up and are already IN ATTI mode. As I stated before, if you power up in ATTI mode your drone will default to GPS lock. There are some exceptions, but that's generally how it works. Don't take my word for it. Try it.

D

 

[bsartist]

So you were able to fly OUT THROUGH an NFZ, but not able to take that same path BACK through the NFZ??? This makes no sense.



Did you try putting your drone in ATTI mode? Forced landing is a "smart function." It's been my profound experience that ATTI mode disables all smart functions.

Another thing that bother me about this post is I have tried to fly my Inspire 1 into an NFZ before and the drone just stops dead in its tracks. It never tried to land. I have also flown my P4P within 1.5 miles of a Class D airport for a mapping project. Though I was not able to engage any smart functions, I WAS able to fly the mission manually. Neither drone ever tried to land itself. So I can't help but think something else may have been going on.

Thoughts?

D

Sorry for the delayed response. Correct it makes no sense but I’m not crazy. Something spurious happened. I was able to fly out the same path but on the way back it decided it was in an NFZ and started auto land. These was a message in the stating such. Too long ago to recall exact wording. It‘s less than a mile from my house and I’ve flown that path many times before. The only warning I ever got was the unpaved airport due to a charted seaplane strip out in the middle of lake. Never declared as an NFZ and not on the sectionals as any kind of controlled airspace. And I was over land flying away from that. Never stopped me from takeoff.

As to why yours stopped dead rather than land, you may have hit the boundary. If something spurious happened in my case it may have just decided I was already inside the NFZ and that may force the auto land.

I did not try ATTI.

Bill

 

[bsartist]

The usual explanation for that situation is that the drone was launched in, or flew into the NFZ before GPS reception was established.

This didn’t happen in this case.