RTH Tragedy

[Afremont]

I see there is an option to go around obstacles rather than over them on RTH. I enabled that. I also tried setting the RTH max altitude to a low number, but the minimum is 20m. I promise to become an expert on the manual, it's generally my nature, but I really couldn't resist putting it around a little.

Previous RC experience is coming back to me, including the natural tendency to yaw in the correct direction with it coming towards me. Not having to manually roll the aircraft to make turns feels a little weird though, but I can't say I dislike it. Taking off and landing is world's easier than fixed wing models.

All in all, I think my drone is going to be okay once I fix the gimbal issue. I think the rest of the systems are performing as they should after the crash. At least it seems to be anyway.

All that said, it seems to me that if one got to their current location from the takeoff point without going above 15', immediately rocketing to 30m might not be the best way to begin a RTH, especially since it has the ability to go around obstacles not necessarily over them when performing the maneuver. Live and learn.

Time to RTFM now, it's too dark to fly.

 

[sar104]

So is answering their question. That is the point I was trying to make. Or , are you one of those that just says,"Reading the manual".

If that was in answer to my comment then no - answering questions and recommending reading the manual are not mutually exclusive. I've been known to answer the odd question both here and on PP.

 

[Afremont]

This nay be a bit late, but what do you think would happen if I had purchased care refresh? Since it was due to pilot error, do you all think they would have charged a lot to fix it?

 

[f3honda4me]

This nay be a bit late, but what do you think would happen if I had purchased care refresh? Since it was due to pilot error, do you all think they would have charged a lot to fix it?

Probably not. The repair costs are usually pretty reasonable.

 

[pixl]

This nay be a bit late, but what do you think would happen if I had purchased care refresh? Since it was due to pilot error, do you all think they would have charged a lot to fix it?

DJI would've just swapped it out with a new (refurbished) one for $79. That's the way the program works.

 

[dbyantis]

Here is a thought: Since the Mavic can be set for obstacle avoidance on RTH (which I have always turned on even if I have it turned off for regular flying), it should be possible to just set like 20' altitude or something like that and let the Mavic figure out if it has to go higher. Of course, this could still be problematic if the home direction would point it at the trunk of the tree it is flying under....

I would not trust the sensors to detect everything, wires can be missed, etc. Depending on your battery strength, the time consumimng step up to RTH may drain it to a point of no return, so I would review the area and wind where you are flying and set it accordingly for EACH flight.

 

[MAvic_South_Oz]

I see there is an option to go around obstacles rather than over them on RTH. I enabled that. I also tried setting the RTH max altitude to a low number, but the minimum is 20m.

Obstacle avoidance can't read some finer tree canopy, thin branches, powerlines.
Always set RTH to higher than the surrounding trees etc, otherwise it's possible to come to grief still, don't depend on obstacle avoidance to work for all things.

If you have a RTH happening for any reason, you can cancel it by hitting the pause button, or the little cancel window X on the Go4 display.
If RTH is happening due to wireless signal loss, you can take over again after it comes back into range, or as previously mentioned, safer in many situations (like flying in dense woodland, around buildings, etc), is to set wireless signal loss to hover and you move closer (or better line of sight) to the drone to regain control.

Lots to learn about these essential functions.

 

[flymike12650]

Hello, first post and new to drones. I'm sure this is all my in doing, but I do have a question. I used to fly RC planes a lot, but it's been a while.

Yesterday, I was showing my new Mavic Pro to friend. I flew it around the front yard at less than 20' and all was fine until I was going to show him how it could fly itself back to home. I pushed the button and the drone immediately rocketed straight up into a tree canopy and then proceeded to do it a couple more times before dropping to the concrete driveway (naturally). I broke the camera gimbal mount (actually the anti-vibration plate) and ripped the flat circuit cable in half. Video still works, but of course I get motor overload messages about the gimbal. I watched a bunch of repair videos and I think I can fix this myself for about $40. At least I don't seem to need a full $300 camera setup or even the metallic thread video cable. I've worked on mechanical wristwatches before, so I think I can delicately handle this surgery.

My question is about overhead obstacle avoidance. Does it have any ability to do that?

BTW, I won't be flying in the yard anymore until I know every aspect of the software features. Before the crash, I also got messages about heavy interference and experienced blocky video to my phone even at very close range. Is that likely from the phone's WiFi being turned on during flying?

Thanks for reading.

Same thing happened to me on my first day. The aircraft shot up through a pine tree in my back yard showering me with pine needles and pushing my heart rate up. It came down okay with only cracks to two props. Very embarrassing since I'm an airline pilot . . .

 

[Callum]

I see there is an option to go around obstacles rather than over them on RTH. I enabled that. I also tried setting the RTH max altitude to a low number, but the minimum is 20m. I promise to become an expert on the manual, it's generally my nature, but I really couldn't resist putting it around a little.

Previous RC experience is coming back to me, including the natural tendency to yaw in the correct direction with it coming towards me. Not having to manually roll the aircraft to make turns feels a little weird though, but I can't say I dislike it. Taking off and landing is world's easier than fixed wing models.

All in all, I think my drone is going to be okay once I fix the gimbal issue. I think the rest of the systems are performing as they should after the crash. At least it seems to be anyway.

All that said, it seems to me that if one got to their current location from the takeoff point without going above 15', immediately rocketing to 30m might not be the best way to begin a RTH, especially since it has the ability to go around obstacles not necessarily over them when performing the maneuver. Live and learn.

Time to RTFM now, it's too dark to fly.

I had about 10 years experience flying CP helis.

With fixed wing and helis you had to learn to make constant adjustments to maintain attitude and keep your bird in the air. You know yourself it was a steep learning curve as you were in complete control.

With these quads I've found it's a different type of learning.

As you are never in 100% control you are learning how the flight computer operates and how its operation could cause a crash in the wrong circumstances.

You need to know how the quad will react under every condition to avoid getting in a sticky situation.

It becomes second nature very quickly.

 

[pixl]

I had about 10 years experience flying CP helis.

With fixed wing and helis you had to learn to make constant adjustments to maintain attitude and keep your bird in the air. You know yourself it was a steep learning curve as you were in complete control.

With these quads I've found it's a different type of learning.

As you are never in 100% control you are learning how the flight computer operates and how its operation could cause a crash in the wrong circumstances.

You need to know how the quad will react under every condition to avoid getting in a sticky situation.

It becomes second nature very quickly.

That's actually a good analogy -- we are learning how to fly the computer, while it's the computer that flies the drone. It's less so with the Phantom and Inspire -- where you can switch to ATTI and take more responsibility for flight management.

 

[RayOZ]

Not too surprised. First time users will be keen to get their new toy off the ground, show off a bit. Same with me. When I got my Spark (first DJI drone), enough though I printed the manual in a booklet form to put in the carry bag, I only had a quick glance at the manual, as my mind was distracted/itching to see the Spark off the ground. Sure enough, first attempt to auto launch and auto land, it drifted side ways and crash. I wasn't even patient enough to put on the prop guards, which would've saved the props.
After a few months with the Spark and gained some experience, I got my Mavic. I took it slowly, firmware updated, get everything prep'd, calibrated, GPS locked, check surroundings, etc before even starting the motors. We seem to learn better by making mistakes.

 

[Callum]

That's actually a good analogy -- we are learning how to fly the computer, while it's the computer that flies the drone. It's less so with the Phantom and Inspire -- where you can switch to ATTI and take more responsibility for flight management.

Yeah, I wish mavic had a selectable atti mode although even atti mode the computer is basically flying the quad, your only telling it which direction you want it to go and it will maintain attitude and altitude.

Acro mode on a quad or Heli is another story, crashing your model was part of the learning curve.

It really is amazing how things have came on, I don't think I could go back.

 

[AnchorageAk]

I know I should have studied harder. I watched all the DJI promotional videos, but I should have put a lot more effort into going through the menus and understanding what all the options are about. That said, I put my gimbal lock on to keep the video cable from being tugged at and took the drone to a much safer location to play/learn. It's hovering fairly decently, but there was a little bit of a breeze. I have trouble with the phone app disconnecting and poor video etc. I turned off wifi and Bluetooth on the phone, but that didn't much, if any at all.

It might be the USB connector on my Moto g4, I can tell when charging the phone that moving the cable will cause a disconnect and reconnect. That may be the root of most of my trouble. That's probably more than the Go 4 app can tolerate. When I separate the phone from the controller, everything seems to work fairly smoothly. No disconnects from the drone.

I do notice that the reported height, not clearance, will drop as I run back and forth over a 50-75' distance. I'm thinking that is from GPS bouncing around as it does, especially with altitude. I'm guessing without the phone providing a second opinion it errors on the side of caution.

BTW, I was having these phone app disconnects and poor video before the crash. Again, I'm thinking the USB connection to the phone is just flakey enough to cause a lot of data communication errors between the phone and the controller. I have a pretty extensive background with embedded software and hardware such as mems sensors like gyros and accelerometers. I'm hoping that if the aircraft is getting crazy data from the obstacle cams and ultrasonic sensors that it will show up on the phone messages. Right now, it only complains about gimbal issues and interference when I'm near my home. The interference messages seemed to go away when I got away from the plethora of wifi points, but the video to the phone still had issues.

Thanks again for reading my plight.

I hope you keep posting. Most people are here to help, but not everyone. They will even help with your spelling. RTF means exactly that to most people who have had no dealing with remote aircraft. Just because you own an aircraft; however, doesn't make you a pilot. As I mentioned earlier, at least NOW DJI is suggesting you read the manual. Which everyone should do, and was never one of the points I was trying to make. Encouraging people to post was one of them.

 

[Mossiback]

I see there is an option to go around obstacles rather than over them on RTH. I enabled that. I also tried setting the RTH max altitude to a low number, but the minimum is 20m...

RTH is a great feature that can wreck your Mavic. If you set it to a low height and to go around obstacles it will happily fly sideways into something because it has no sideways sensors. It's main purpose is to bring the Mavic back if the battery runs low or it loses contact with the RC. When activated you may not see it or be able to control it so the RTH settings are dependent on the flight. If you are flying under something, set it to hover. If in the open, set the RTH altitude higher than anything around then take control as soon as you can (if for no other reason than to turn off the annoying beeping).

 

[Simmo]

Hey Afremont, I think you said you left the gimbal lock on to stop it tugging on the cable??? Leaving that on and stopping the gimbal's movement generally does give that gimbal overheat error.

 

[Mossiback]

...when I test flew it after the crash (hovering 3' above the ground) it wasn't sitting perfectly still in the air. It went up and down a little and back and forth several inches. I chalk that up to having no camera view of the horizon, but is that a fair assumption? I'm wondering if I may have damaged a gyro chip. Thanks again for your help.

The Mavic uses its downward facing cameras and ultrasound to get that steady hover. It does not use a camera view of the horizon. It requires adequate light, a unique target to look at, and clean lenses to work. I am guessing your gyro is okay.

 

[Afremont]

I put the gimbal lock on to hold the camera in position since it broke free of the mount. Parts will be here tomorrow evening. Changing the ribbon and putting in a new stabilizer board looks challenging, but doable. Probably should gave bought the DJI care refresh, especially since the phone app is apparently a complete disaster right now for many folks, including me and my Moto g4.

I might contact them today to see if I can still sign up for future use should I have it fly away because of the Go 4 app problems.

 

[pixl]

I put the gimbal lock on to hold the camera in position since it broke free of the mount. Parts will be here tomorrow evening. Changing the ribbon and putting in a new stabilizer board looks challenging, but doable. Probably should gave bought the DJI care refresh, especially since the phone app is apparently a complete disaster right now for many folks, including me and my Moto g4.

I might contact them today to see if I can still sign up for future use should I have it fly away because of the Go 4 app problems.

If you're going to do that, don't tell them about the crash and repairs, as any repairs you perform yourself voids their warranty. If you want to buy Refesh now, there's a procedure that you have to go through that shows that your drone is in good working order.

 

[Afremont]

I guess I'll have to fix it first, unless that doesn't involve having a moving camera. The video is fine, but the gimbal cable isn't. I'm willing to own up to my own flying errors, but with what I've been reading about the phone app I want some insurance that they'll own up to theirs.

Edit:. BTW, I just bought it Friday. I didn't learn about the frightening Go 4 problems until last night, right after my 48 hours were up.

 

[Ozman]

Feel sorry for you, it must have been sickening to watch. My only tip is don’t use RTH, there is no need to ever. In my opinion it’s just laziness. I’ve had mine for over six months and never used it once. I manually take off and manually fly it back and land it. If the aircraft decides to initiate the RTH function then it’s for a reason (loss of signal or low battery). That’s the only real purpose of the RTH function. So many people have crashed their Mavic’s by using this function when there was absolutely no need to do so. Not lecturing friend just offering some advice, take it or leave it. Cheers.