(Warning) Avoid this low battery RTH mistake

[Kilrah]

There is only one way to turn any UAV on and one way to turn it off.

Turning ON
Controller on, wait until it’s ready to receive a signal THEN the drone.

Turning OFF
Drone off, wait until the controller registers this THEN turn the controller off.

Completely irrelevant with current tech.

 

[Quad808]

Well done sir! I am still smiling...hahahahaha!
-20 hahahaha...oh no, it's really nice....LOL! Priceless...I had to watch it again

 

[demme]

There is only one way to turn any UAV on and one way to turn it off.

Turning ON
Controller on, wait until it’s ready to receive a signal THEN the drone.

Turning OFF
Drone off, wait until the controller registers this THEN turn the controller off.

Any other way and you risk the UAV thinking it’s lost a signal and going rogue, sorry this completely user error and a newbie mistake! This isn’t really a warning more a tail of how not to do things. Never turn the controller off unless you have confirmed that the UAV is completely off.

G

Nah, before I'm going to do a flight, I turn on aircraft first, it will do nothing since it has been offline. Not like "oh yeah my last flight rth was not here, I will just take off and go there, even though I've been offline, packed in a case for one week".

I prefer aircraft first to get satellites faster, when dji app is running after RC has been turned on, with luck I will already have enough sat count for a precise homepoint and can takeoff almost right away.

Not saying it's the best or correct sequence, but I do it like that.


And I quote you "Any other way and you risk the UAV thinking it’s lost a signal".

How will, a just turned on mavic with RC still off, think something is wrong? Nothing is wrong, it has no connection with it yet. It even flashes in in the rear telling you this, if you are aware of what all the rear light combos mean.

It's pretty logic what OP did wrong, I'm no expert but it doesn't take much IQ to figure it out. And I saw someone reconstructing it on a video, nice one You take good care of your bird, not in any distance leaderboard I assume

 

[Garry]

It looks to me that DJI need to look at that scenario, it should not lift off the ground on its own in rth mode. Be interesting to see any further opinions from the more experienced users!

What if you flying from I higher take off point and you descending to a lower point you don’t want the props to stop because of the lower altitude,, you should of made sure the props weren’t spinning by looking at the ground for shadows of them

 

[MavicAirMike]

I saw the same thing in a video last year when somebody was flying their Mavic Pro ... they were flying along the White Cliffs of Dover. He was running out of battery, so he landed it, got in his car and drove to the place where he was going to pick it up. Only thing is, as he turned off his remote, it then "broke signal" and went into RTH mode. He lost his in a thicket of trees and to this day, I'm not sure he was able to locate it.

Point I learned there is "Never turn off your controller until your Mavic is in your hands".

 

[kakao]

Point I learned there is "Never turn off your controller until your Mavic is in your hands".

Amin!

 

[MavicMoira]

I have read through all the posts on. This subject and it seems that everyone is forgetting that there was apparently a gap of 5 minutes between the MP "landing" and the unexpected takeoff. The RTH then would not have been triggered by loss of signal from the controller as that would happen within seconds of the controller being switched off. I am therefore forced to the conclusion that there IS something very unusual happening. If the props were still spinning the RTH would have happened straight away. If the props were not spinning then the MP should have been unable to takeoff. Unless......

What if it picked up a stray radio signal? Which, after all, is why we are advised to turn on our controller before turning on the MP.

 

[PaoloOne]

Check post #41... I was surprised that this side of the conversation didn't get tossed around more ~but it has been mentioned.

(Warning) Avoid this low battery RTH mistake

I see what you say and you meant the same, but is not about setting the return to home function, it is about which action to perform on signal loss. So It is more about calling things with their names to avoid confusion.
Basically you may say to your drone, forget about returning home, in case of signal loss and low battery just do one thing: Land!

 

[Kilrah]

I also mentioned in the very first answer to the OP that you might want to set HP to current aircraft location before attempting a landing, which would have the same effect.

What if it picked up a stray radio signal? Which, after all, is why we are advised to turn on our controller before turning on the MP.

Communication on these devices is very complex and encrypted, so a "stray signal" doing anything to it is basically impossible. Nothing in common with old RC stuff.
The gap was not between the landing and the unexpected takeoff, it was between the landing and the owner noticing it was in the air. It simply was in the air for those 5 minutes without him noticing.

 

[MavicMoira]

I also mentioned in the very first answer to the OP that you might want to set HP to current aircraft location before attempting a landing, which would have the same effect.


Communication on these devices is very complex and encrypted, so a "stray signal" doing anything to it is basically impossible. Nothing in common with old RC stuff.
The gap was not between the landing and the unexpected takeoff, it was between the landing and the owner noticing it was in the air. It simply was in the air for those 5 minutes without him noticing.

That makes sense and does explain the whole situation. Thanks for clearing that up!

 

[ckonstantar]

Hi guys,

I had a near miss. I just wanted to alert you of this so nobody loses their Mavic Pro.

I was filming a lake.
I parked my car on one side of the lake and I launched my drone from the opposite side of the lake.

I completed my filming and knew the drone's battery was pretty low at around 18%. Time to wrap things up.
I thought I would be clever and just land my drone near my car, so that I didn't need to carry it back to the car.
I landed it via the video feed and confirmed that it was actually stationary on the ground.

I unplugged my phone and turned off the Mavic controller. I completely packed everything away.

After about 5 minutes, after walking halfway back to the car, I suddenly heard my Mavic in the air!!

Confused and freaking out, I opened my bag and turned on the controller on again (without a smartphone). As soon as it connected to the drone, it immediately starts beeping, indicating that the battery was now very very low (eg, single-digit %)

Because the battery had dropped to a certain level while it sat idle on the ground beside my car, it had autonomously taken off again, climbed to the RTH altitude I previously set (100m) and heading 'home', over the middle of the lake.

It didn't have enough battery to make it home. Mid-way through it's RTH course over the lake, the battery reached the critically-low threshold and it began doing an forced-decent over the middle of the lake.

I could not override this descent - however I was fortunate on this occasion because I had a physical line-of-sight to the drone from where I was standing. I was even more fortunate that I was able to manually roll the drone sideways and steer this forced-descent onto a patch of dirt which happened to be beside this particular section of it's RTH course.
(again, my phone wasn't plugged in to the controller so I had no video feed; it was all manual)

On this occasion the drone wasn't destroyed, but this was a very, very close call.

I understand that the drone will return to home on low battery and lost signal...but I was surprised that it will do this even after the pilot has landed it somewhere else. This seems to be a loop-hole in the RTH algorithm.

If I ever want to land the drone at an alternative site, how can I land it and STAY THERE, even when the battery gets low? (assume I'm flying using just the manual controls, ie, without a smart phone)

Has this happened to anyone else?

Please be careful of this, guys.

EDIT:

Here is the flight log of the flight.
This flight was about 6 weeks ago, with many uneventful flights since. You'll have to forgive me if some of my earlier recollection of the event was inaccurate in my initial post.
I have deliberately removed all the GPS coordinates for confidentiality.
What I can tell you is: the take-off point was also the 'home point'. The landing point was not the home point.

DJIFlightRecord_2018-01-03_(11-39-13) (GPS coordinates removed).xlsx

Although I understood clearly the issue, I want to remind : The practice is first to shut down the drone and after the controller.

 

[joejaxvic123]

I was watching NASCAR earlier....

 

[Qoncussion]

I see what you say and you meant the same, but is not about setting the return to home function, it is about which action to perform on signal loss. So It is more about calling things with their names to avoid confusion.
Basically you may say to your drone, forget about returning home, in case of signal loss and low battery just do one thing: Land!

Point taken... But you know what I meant

 

[Qoncussion]

It simply was in the air for those 5 minutes without him noticing.

Same conclusion I reached as well.

 

[MacPhersonCa1]

Yes, this is a good idea.

But the key take home message of this is:

- Do not attempt to land the drone manually while in Sports mode (nor any other configuration which disables the downward sensors).
- Maintain line of sight to your drone, especially when you're landing


2) Enable downward sensors (ie, turn off Sports mode) before landing manually,

Sport mode does not turn off downward sensors, only the forward sensors.

 

[MavicMoira]

...........Communication on these devices is very complex and encrypted, so a "stray signal" doing anything to it is basically impossible. Nothing in common with old RC stuff.
The gap was not between the landing and the unexpected takeoff, it was between the landing and the owner noticing it was in the air. It simply was in the air for those 5 minutes without him noticing.

However, it still doesn't answer the question as to why it did not initiate an RTH as soon as the controller was turned off......

 

[Lest 37]

I came on here genuinely trying to help some other people but have unfortunately come up against a bunch of arrogant know-it-alls. Seems a bit toxic around here.

And thanks for doing so, I’ve been a member on here for a little while now and regularly check in to see what’s going on in the mavic world, from around the world, and think that it’s s great place for mavic pilots to share there problems and exsperiences, but increasingly post after post now people are to quick to start poking and picking at people, the biggest one is, he’s obviously a novice, or he’s obviously a newbie etc, these people have quickly forgot that they was also a novice and a newbie at one point and that a lot of them need to come down of there high horses, most of these people wouldn’t say diddley squat if they saw you face to face but act like billy big bollocks on here.

 

[TerryJ]

Hi guys,

I had a near miss. I just wanted to alert you of this so nobody loses their Mavic Pro.

I was filming a lake.
I parked my car on one side of the lake and I launched my drone from the opposite side of the lake.

I completed my filming and knew the drone's battery was pretty low at around 18%. Time to wrap things up.
I thought I would be clever and just land my drone near my car, so that I didn't need to carry it back to the car.
I landed it via the video feed and confirmed that it was actually stationary on the ground.

I unplugged my phone and turned off the Mavic controller. I completely packed everything away.

After about 5 minutes, after walking halfway back to the car, I suddenly heard my Mavic in the air!!

Confused and freaking out, I opened my bag and turned on the controller on again (without a smartphone). As soon as it connected to the drone, it immediately starts beeping, indicating that the battery was now very very low (eg, single-digit %)

Because the battery had dropped to a certain level while it sat idle on the ground beside my car, it had autonomously taken off again, climbed to the RTH altitude I previously set (100m) and heading 'home', over the middle of the lake.

It didn't have enough battery to make it home. Mid-way through it's RTH course over the lake, the battery reached the critically-low threshold and it began doing an forced-decent over the middle of the lake.

I could not override this descent - however I was fortunate on this occasion because I had a physical line-of-sight to the drone from where I was standing. I was even more fortunate that I was able to manually roll the drone sideways and steer this forced-descent onto a patch of dirt which happened to be beside this particular section of it's RTH course.
(again, my phone wasn't plugged in to the controller so I had no video feed; it was all manual)

On this occasion the drone wasn't destroyed, but this was a very, very close call.

I understand that the drone will return to home on low battery and lost signal...but I was surprised that it will do this even after the pilot has landed it somewhere else. This seems to be a loop-hole in the RTH algorithm.

If I ever want to land the drone at an alternative site, how can I land it and STAY THERE, even when the battery gets low? (assume I'm flying using just the manual controls, ie, without a smart phone)

Has this happened to anyone else?

Please be careful of this, guys.

EDIT:

Here is the flight log of the flight.
This flight was about 6 weeks ago, with many uneventful flights since. You'll have to forgive me if some of my earlier recollection of the event was inaccurate in my initial post.
I have deliberately removed all the GPS coordinates for confidentiality.
What I can tell you is: the take-off point was also the 'home point'. The landing point was not the home point.

DJIFlightRecord_2018-01-03_(11-39-13) (GPS coordinates removed).xlsx

Very odd! After you landed and shut down the motors it should have recorded that spot as its new home point. At least I thought it worked that way. Did you call DJI? What was their response? Glad it all worked ok for ya!! Losing $1500+ dollars in a lake is NO fun at all!!! Please let us all know the dji response and how to insure this cant happen if we do the same thing. Very curious as to how/why this occurred.

 

[TerryJ]

And thanks for doing so, I’ve been a member on here for a little while now and regularly check in to see what’s going on in the mavic world, from around the world, and think that it’s s great place for mavic pilots to share there problems and exsperiences, but increasingly post after post now people are to quick to start poking and picking at people, the biggest one is, he’s obviously a novice, or he’s obviously a newbie etc, these people have quickly forgot that they was also a novice and a newbie at one point and that a lot of them need to come down of there high horses, most of these people wouldn’t say diddley squat if they saw you face to face but act like billy big bollocks on here.

I probably would be considered one of those jerks at times. I'm so tired of people blaming DJI because they couldn't take a few hours of time to READ THE MANUAL. I'm tired of lazy people who ask ridiculous questions because they're to lazy to find the answer themselves. That and people blatantly breaking the law because they feel it doesn't apply to them some how is also something I have ZERO patience for.
We all start at the beginning and have to learn but lazy and law breaking drone owners get nothing from me but ****!!!
I will never talk down or give a person a hard time because they're new to drones and are just starting to learn about it. Just PLEASE be responsible and fly within the laws or regulations and READ YOUR MANUAL before you ever even turn it on.

 

[dbyantis]

Very odd! After you landed and shut down the motors it should have recorded that spot as its new home point. At least I thought it worked that way. Did you call DJI? What was their response? Glad it all worked ok for ya!! Losing $1500+ dollars in a lake is NO fun at all!!! Please let us all know the dji response and how to insure this cant happen if we do the same thing. Very curious as to how/why this occurred.

The meat of this thread discusses how the motors, probably did not stop, and that the RTH was initiated by the RC disconnect, not low battery.