Mavic Lost! Failure to Return to Home

[Reaper Two Seven]

Bummer man. But, I mean a return to home set at 90M (295 feet) around 450 foot buildings?

As I replied earlier to another post, I typically do not fly near tall buildings. Most of the time I fly in my neighborhood, where 295 feet is not an issue. I set it at that on my inaugural flight last night and failed to change it to suit the circumstances today.

 

[Reaper Two Seven]

Go see deckdog post about his Mavic. They should send you a new one. I said 'should' if it was me I'd burn up their phone lines. Until a drone was resent. FedEx of course[emoji18]


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I will check that out. I have read another post today about a flyaway where it was covered by DJI so that has given me hope. I do believe that the product did not perform as advertised because with smart return to home it should have seen an obstacle as big as a skyscraper and stopped. But then again, would it detect glass as in glass windows? Another reason and lesson learned for me not to embrace technology implicitly. Believe me I plan to raise some kind of hell over this and will keep this thread updated as to the final verdict of the DJI gods.

 

[Reaper Two Seven]

I have two observations here.
1) You said you were losing signal so you started to ascend for the return home. Ascending was only making the distance between you and the mavic greater which is probably why you lost signal.
2) You flew out 7800 feet and your battery was down to 47%. How did you expect to get back if you had already used more than half your battery. There's a possibility your mavic started to fly back but hit the critical battery level and was forced to land somewhere in between.

I was ascending because I was noticing some dropouts/sluggishness with the video feed in the belief that height would allow me to establish a stronger link. I made the mistake of not monitoring my battery because I was concentrating on navigating downtown buildings. I was also in a state of delight / euphoria because this was one badass drone. I'm sure you all know that feeling. I had not gotten a low battery or "bingo fuel" alert and I am fairly confident that at 47% I had enough juice to get back. A mile and a half at 47% is perfectly doable.

 

[J3ffrey]

Pretty sure you shouldn't be flying around anywhere that you have to avoid buildings man... making the rest of us look bad.

 

[Reaper Two Seven]

When the remote controller disconnects, RTH should be initiated. Based on the last location in the log, you might be able to figure out where it landed/crashed.

I looked at the flight record that shows the map and fight path and last place it lost contact was what I saw in the video feed so that would not have helped me.

 

[msinger]

I looked at the flight record that shows the map and fight path and last place it lost contact was what I saw in the video feed so that would not have helped me.

I'd be happy to review it if you will share the link. I've helped many people find crashed drones by reviewing their logs.

 

[Reaper Two Seven]

You said you had the VPS off.. Did you also turn off the Obstacle Avoidance system? Failsafe RTH will NOT use the OA to avoid obstacles if the OA is off... Page 13, 2nd section under "Failsafe RTH", 2nd point below..

If OA is off, then I believe the Mavic probably hit a building on the way back...

You can download the manual at: Mavic – Specs, FAQ, Tutorials and Downloads

I had the forward sensors turned OFF. Smart return was ON. I have used the same settings on my P4 and obstacle avoidance was enabled when it lost signal and RTH. I only knew about it when I reviewed the video and saw that it almost hit a stand of trees and stopped in time to go up and over them. But I will look at the manual to see if what you brought up is accurate.

 

[Reaper Two Seven]

Pretty sure you shouldn't be flying around anywhere that you have to avoid buildings man... making the rest of us look bad.

I know......

 

[Reaper Two Seven]

I'd be happy to review it if you will share the link. I've helped many people find crashed drones by reviewing their logs.

How do I upload it from my iPhone?

 

[msinger]

You'll need to use iTunes in order to retrieve the TXT file. See the instructions here.

 

[Reaper Two Seven]

Update: After today's fiasco I enlisted the help of a friend who has a Phantom 3 Professional. We met downtown at the last known Mavic location and he set off looking at rooftops and parking areas from the air to see if we could locate my lost drone. He made a Skyhook(tm) which is a treble hook fashioned out of coat hangers with parachute cord. In practice it works well and he can lift 2 pounds with ease. We did not see it and he started to retrace my "footsteps" back to my original home location. He was about 200 feet up and 300 feet away. When he flew around the building he promptly lost signal no more than 400 feet away. RTH automatically initiated and before he could cancel it his drone flew smack into the building. He took evasive measures and tried to back it up but it still hit. It took about 100 feet dive and landed at the top of a parking garage. He set off immediately to recover it and found it. He didn't even have to pay for the parking on his way out. Shell is cracked beyond repair and the gimball / camera has been thrown from its mount. Everything else looked pretty intact. On of the ribbon cables to the gimbal / camera assembly is cracked at the connector but still connect-able. It is repairable. Man do I feel really bad now. And if my drone did hit the building on the way back (and it certainly is a possibility as it would have been likely to be on the flight path back as the crow flies) then that means he hit the building on one side and I hit it on the other.

Building: 2
Drones: 0

 

[vashon100]

You discovered a devil's rectangle!

 

[Multicoptertec]

You say you charged the batteries, and did firmware updates, but did you ever calibrate the compass? A wandering drone usually means a bad compass calibration. Once you saw the initial drift, you did a stick calibration. I would have done a compass calibration and some test flights in a more controlled environment before venturing out as you did. Your RTH altitude was obviously not planned well. In your eagerness to fly, you ignored several items in you flight plan, or lack thereof. Same with your buddy. Good luck, hope everything works out. Lessons learned.


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[Reaper Two Seven]

You say you charged the batteries, and did firmware updates, but did you ever calibrate the compass? A wandering drone usually means a bad compass calibration. Once you saw the initial drift, you did a stick calibration. I would have done a compass calibration and some test flights in a more controlled environment before venturing out as you did. Your RTH altitude was obviously not planned well. In your eagerness to fly, you ignored several items in you flight plan, or lack thereof. Same with your buddy. Good luck, hope everything works out. Lessons learned.


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Battery was fully charged. Firmware on latest update and I did calibrate before I flew. All good points in the RTH altitude. With experience comes complacency and poor planning. Not a lot of people's first rodeos but that can lead to cockiness which can be dangerous. A healthy dose of paranoia is your friend when it comes to flying these expensive robots. Expensive lesson learned. I share this for the benefit of the forum to not repeat my mistakes.

 

[Reaper Two Seven]

You said you had the VPS off.. Did you also turn off the Obstacle Avoidance system? Failsafe RTH will NOT use the OA to avoid obstacles if the OA is off... Page 13, 2nd section under "Failsafe RTH", 2nd point below..

If OA is off, then I believe the Mavic probably hit a building on the way back...

You can download the manual at: Mavic – Specs, FAQ, Tutorials and Downloads

I believe I'm a screwed pooch on this one.... I read the manual in the section you pointed out and on page 16 at the top under RTH Safety Notices it says:

"The aircraft cannot avoid obstructions during RTH when the Forward Vision
System is disabled. Therefore, it is important to set a suitable Failsafe altitude
before each flight. Launch the DJI GO app and enter “Camera” and tap
to set the Failsafe altitude."

Crap. I don't think DJI is going to cover this. Everyone please take note of this and plan accordingly. If you're like me, or most people, you're a hands on type of person and don't take the time to read the manual first. If you haven't gotten the Mavic yet, READ THE MANUAL IN ITS ENTIRETY before flying. Save yourself an expensive lesson.

 

[Stefan350]

I was ascending because I was noticing some dropouts/sluggishness with the video feed in the belief that height would allow me to establish a stronger link. I made the mistake of not monitoring my battery because I was concentrating on navigating downtown buildings. I was also in a state of delight / euphoria because this was one badass drone. I'm sure you all know that feeling. I had not gotten a low battery or "bingo fuel" alert and I am fairly confident that at 47% I had enough juice to get back. A mile and a half at 47% is perfectly doable.

I do this with my P4 too, whenever I feel like testing the distance. Ascending seems to always help.



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[Reaper Two Seven]

I do this with my P4 too, whenever I feel like testing the distance. Ascending seems to always help.



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It has usually helped me 99.997% of the time. I'm sure you can figure out the 0.003% when it didn't help.

 

[Crashburn]

And there is the vitriol. I knew it was coming.

Join my club, I feel your pain

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[Anthony]

Sorry to see you lost your Mavic....

But can I ask why did you turn off the Forward Vision System ?

I am not new to flying RC but very new to Drones so I was planning on taking full advantage of the on board systems to assist with my venture into the world of drones and as someone new to drones I am very curious as to what would be the logic behind disabling this on board system as its main function seems to be a safety feature.

Is it that the Mavic operates differently than the drones you are currently using ?? do other DJI drones when loosing connection re enable any safety features ?? if not maybe DJI need to consider adding this to the next update so that once connection is lost it auto enables ALL of the safety features.

 

[Reaper Two Seven]

Sorry to see you lost your Mavic....

But can I ask why did you turn off the Forward Vision System ?

I am not new to flying RC but very new to Drones so I was planning on taking full advantage of the on board systems to assist with my venture into the world of drones and as someone new to drones I am very curious as to what would be the logic behind disabling this on board system as its main function seems to be a safety feature.

Is it that the Mavic operates differently than the drones you are currently using ?? do other DJI drones when loosing connection re enable any safety features ?? if not maybe DJI need to consider adding this to the next update so that once connection is lost it auto enables ALL of the safety features.

I turn off the forward vision system because with it on the top speed is limited to 22 MPH. With it off the drone will do 35MPH. The slower speed obstensibly allows it time to react to obstacles. Normally when you're in an open area with nothing tall around and at altitude this is a non issue. 300 feet up in my housing addition there is nothing to hit so turning it off allows me to navigate faster. I will enable the front sensors when operating closer to the ground or around tall objects. That's what I should have done yesterday but I didn't. I happened to be chasing a train and got a great shot of the train moving in the foreground with the city skyline in the background yesterday so I turned off the forward sensors to be able to keep up with the train. As soon as I began flying near buildings I should have turned it back on. The new Phantom 4 Pro allows you to go 31 MPH with all the sensors enabled so with that speed leaving it on all the time would be no big deal.

I read the manual and it said that when failsafe RTH is initiated and the sensors are turned off that it won't enable them for the trip back. I thought that was what the smart return to home was for. That's a good point about once it loses signal it should turn everything on. That could easily be resolved with a firmware update. My Phantom 4 did that. I was exploring a coastal area in New Hampshire with the forward vision system turned off when it lost signal. On the return trip back it automatically avoided trees before reestablishing contact. I made the wrong assumption that this latest and greatest drone did the same thing but it apparently does not.