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Mavic Lost! Failure to Return to Home

Yes, why in the world would you turn off the coolest thing about it?! the sensors?!
 
Yes, why in the world would you turn off the coolest thing about it?! the sensors?!
Because its unreliable.
It has been fooled many times by just lighting and making the aircraft refuse to fly forwards.
It needs refinement (like nearly everything DJI release in the early life cycle of a product)
A few more updates and I'm sure it will perform as it was intended.
For now, it is an (unreliable) gimmick
 
interesting, so the take home message for now i think is
if you are flying close, have sensors on
if your are far off, potentially having a RTH triggered, then turn them off. right?
 
UPDATE:
[msinger] rocks!

+1 to that.

And thanks for sharing all this with us, Reaper. Reading about lessons learned from crashes is, in my opinion, one of the best and most useful parts of a forum like this. And as far as the public beat downs that some like to dish out go, I doubt they're likely to change anyone's flying behavior, but they may very well succeed in discouraging honest and open discussions about it.
 
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interesting, so the take home message for now i think is
if you are flying close, have sensors on
if your are far off, potentially having a RTH triggered, then turn them off. right?
Thats what i would do, yes...

But of couse its just a compromise until DJI did its homework...

Ender
 
First of all congratulations on finding / locating your lost Mavic.

I am sure that by now you have learned a few lessons from this incident. It also takes a humble, courageous, and wise man to man up and publicly admit your own mistakes. Be humble to see your mistakes, courageous to admit them, and wise enough to correct them.
Every day I learn something new, we all do. You did what I always tell my daughters " I hate excuses, be real and just admit that you f***ed up".

To all of us in this forum, the OP has publicly admitted to making a few mistakes and has learned from it. He has shown to be a big man to admit his mistakes and confess. You can only beat a dead horse for so long.
 
Great story about the retrieval! Glad you got it back.

It would be cool to see the video of the crash, were you recording? I like the feature on Litchi that enables recording at takeoff. I don't see any reason to not record the entire flight given the size of SD cards these days.

Of course sharing the video is exactly what some people here would prefer not to happen, but my curiosity far outweighs my concern about their opinions :)
 
It would be cool to see the video of the crash, were you recording? I like the feature on Litchi that enables recording at takeoff. I don't see any reason to not record the entire flight given the size of SD cards these days.

Of course sharing the video is exactly what some people here would prefer not to happen, but my curiosity far outweighs my concern about their opinions :)

+1 I totally agree. It would be educational for us to see the video, I feel we can all learn from this.
 
Yes, why in the world would you turn off the coolest thing about it?! the sensors?!
Having the obstacle avoidance sensors on limits the speed of the craft to 22 MPH. Normally this is about as fast as you'd need to go under most conditions. Having them turned off allows you to open up to the maximum non-sport mode of 35 MPH. If you're at altitude with nothing in the way or over flat expanses of land and want to get somewhere quickly you might consider turning them off.

On that day in question I was chasing a rail train and 22 MPH would not allow me to follow / chase / overtake it so I had it off. In fact, in my Phantom 4 days I would leave OA disabled 70 - 80% of the time. But I like having the security blanket of OA avoidance turned on at times when I would need it. I travel a lot with my drone and I've captured fantastic shots of flying up a roaring creek with large boulders to the base of a waterfall in the Smoky Mountains in Tennessee. I flew it low and slow and although OA did not trigger or prevent a crash, having it on provided me peace of mind as I flew it 1100 feet downstream and back. The footage was amazing. During situations like that when I was low to the ground below tree top height OA was useful.
 
Because its unreliable.
It has been fooled many times by just lighting and making the aircraft refuse to fly forwards.
It needs refinement (like nearly everything DJI release in the early life cycle of a product)
A few more updates and I'm sure it will perform as it was intended.
For now, it is an (unreliable) gimmick
The OA avoidance sensors have never triggered any false positives on my Phantom 4 that I can remember. As I stated in another post I usually fly with them disabled most of the time. Having them enabled has not prevented a crash or saved my a$$ when I've been actively piloting the craft, because there hasn't been a need for it to engage. However it has saved me on at least two occasions that I know of. Once, on a smart return to home when I lost connection it flew towards a stand of trees and braked JUST in time to avoid them and flew over them. I was exploring an inter-tidal lowland valley flanked by wooded areas of trees on the coast of New Hampshire. I was skimming just above the surface of the brackish water / vegetation when I lost signal of it. I did not know it did that until later that day when I reviewed the video. Another when I was playing with the active track feature (which I haven't used much) after first getting the P4. I was on a bike and it maneuvered quite evasively and aggressively to avoid plowing into a mailbox. The street that I was on had a slight uphill rise to it. Those two instances made the OA feature worth it, in my mind, over the Phantom 3 Professional that I had just upgraded from. In my experiences having OA turned on during the autonomous flight profiles has made it worth the price of admission. I have not tried to fly it into a wall as others on youtube have but it has kicked in a few times when I've brought it towards me during landing and it sensed me standing there. In one circumstance I was standing on the balcony of a rental cabin high up overlooking the side of a mountain in Tennessee. It was beeping incessantly because I needed to bring it close to the balcony (and side of the building) to land it. I ended up turning it around and reversing it towards me before setting it down on the wide wood planked patio handrail.

I'm sure the feature is far from perfect and each generation of aircraft will improve upon it, as we've seen in the Phantom 4 Pro (OA all the way around, further range, higher top speed). It will be an evolutionary process. But for me, the OA works well enough and I have not noticed any instances of it being unreliable (mistaking the sun as an obstacle, glass windows, etc) but as I said I usually don't fly with it engaged. With the P4 Pro it is only 4 MPH slower with it on so it might be worthwhile to leave it on all the time on that model.
 
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interesting, so the take home message for now i think is
if you are flying close, have sensors on
if your are far off, potentially having a RTH triggered, then turn them off. right?
For me: If I am flying close to obstacles low to the ground or around buildings turn the sensors ON. Far away around tall obstacles with the potential to lose contact and have a failsafe return to home triggered turn them ON. Set your RTH altitude higher than the highest obstacle you will encounter. Wide open area with trees / power lines no higher than 80-90 feet and I'm at 300 feet I turn them OFF, only because I can attain the higher speed with them off. If you're a beginner leave them ON all the time until you're familiar / more confident / more experienced with your craft.
 
+1 to that.

And thanks for sharing all this with us, Reaper. Reading about lessons learned from crashes is, in my opinion, one of the best and most useful parts of a forum like this. And as far as the public beat downs that some like to dish out go, I doubt they're likely to change anyone's flying behavior, but they may very well succeed in discouraging honest and open discussions about it.
Some of the bashing doled out by a minority of the members have been irksome to a small degree. Mainly because it contributes no valuable content and is unhelpful to an after-the-fact incident and their negativity may sadly discourage other members from contributing their stories. That fact was on my mind as stated in my initial post and sure enough it happened. There are ALWAYS a few simple minded people like that in every forum. Always. I'm ok with that because they don't know who I am as a person and I won't lose any sleep with their utterances. As you said, reading about lessons learned in crashes is valuable benefit to the community. Informing other readers of what went wrong can help prevent them from making the same mistakes. If I can spare one pilot from the heartbreak and agony of losing their awesome aircraft along with preventing disasters on the ground I can be satisfied with that.

There is a cost to being open and honest and if everyone faced certain severe prosecution from the authorities none of these stories would ever be shared. Most members have been overwhelmingly supportive and positive and I thank them for that. I am glad I shared my experience. Hopefully we can all benefit from it. As the Greek philosopher Aristotle once said, "The whole is greater than the sum of its parts."
 
Here's my future forecast for this awesome piece of technology: Someone flies through downtown-anywhere into a high rise, it falls hundreds of feet and hurts or kills someone. Then we get to only fly in the rural countryside or RC flying parks. Not very photographic.
Here's a few scenic shots I've gotten in the countryside:

The thing is, you can get great shots anywhere.
 

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Great story about the retrieval! Glad you got it back.

It would be cool to see the video of the crash, were you recording? I like the feature on Litchi that enables recording at takeoff. I don't see any reason to not record the entire flight given the size of SD cards these days.

Of course sharing the video is exactly what some people here would prefer not to happen, but my curiosity far outweighs my concern about their opinions :)
I was recording. And I think it would be cool to see video of the crash as well. After all, I paid for it! Three flights made so far at the average cost of $433 per flight. I was curious too and wanted to see the moment of impact and subsequent fall. That's the part I fast forwarded to upon retrieving the drone and memory card. I watched from the moment I lost control of the Mavic. It hovered for a few seconds, then automatically swung around in the direction of the home point. Ascended the short distance to 90 meters. Then went into forward flight. Closer and closer towards the looming building. It's not gunning it but here it comes..... closer, closer. Nail biting now. Then nothing. The video stops about 3 seconds from impact. Strange, I wondered. But then I realized that maybe it's the way it buffers before saving to the memory card. And at some point during the fall or crash to the surface the battery was forcefully ejected so perhaps it didn't get a chance to write that part to the card. So unfortunately I do not have that moment in video to save for all posterity.
 
I am not seeking that people condone or tolerate or accept my behavior or decisions. I'm not saying that what I did was okay. Anytime you put a drone up in the air its a one pound plus weedwhacker operating overhead. The blades are spinning at such a high speed that getting a finger in the way could result in disaster. Flying a remotely operated drone entails a calculated risk that any number of mechanical, human, weather or other environmental factors could case it to fail or crash or function in a less than expected way. People can most definitely be injured severely or killed by a falling drone. That's not something I'd want on my conscience. I've seen enough drone crash videos on YouTube to know the potential destruction an out of control drone can cause.

We live in a world of calculated risk. Anytime you swim in a pool, mow the lawn, fix an appliance, cook with gas, light fireworks, hang a tv, jump on a trampoline, get out of bed and, the most dangerous activity of all - drive a car. I'm quoting several different sources, but according to the Center for Disease Control and Prevention roughly 8 adults die every day by drowning. Rates of electrocution deaths among men jumped 76 percent between 2008 and 2009—the last year for which data is available, according to a report from the U.S. Consumer Product Safety Commission (CPSC). The most common cause? Trying to fix small appliances like toasters or blenders, the data shows. Unplug everything before going to work. Cooking results in roughly 17,000 serious accidents annually, and many of those involve propane grills, according to another CPSC report. 2,000 people worldwide, are also injured in the attempt to pry apart frozen foods each year. Roughly 9,000 people end up in the ER every year as a result of messing around with fireworks—a number that hasn't changed since 1997, shows another CPSC report. Yeah, fireworks are fun because they're dangerous. It's been said that more people have died celebrating the independence of the United States than fighting for it. Between 2009 and 2011, about 19,000 people were sent to the ER—and 215 were killed—by falling televisions, finds a CPSC report. There are about 100,000 trampoline accidents per year involving broken bones, concussions and dislocations, with at least one fatality annually. And the risks aren’t necessarily from falling off, especially with the use of nets. Collisions while multiple people are bouncing together cause many of the injuries. When you get out of your bed, you have a 1 in 20,000 chance of fatally fracturing your skull by falling according to Rogers Bussey Lawyers. In addition, roughly 130 people are killed by falling out of their bed every year. The number of motor vehicle accidents in the country each year can be over 10 million, with fatalities numbering typically from 30,000 to 40,000 annually. I don't want to be the first, and I'm not trying to downplay it, but how many drone deaths have you heard of? Other than the targeted drone killings in Afghanistan by our military.

So as you can see, unless you want to live your life literally in a bubble, there aren't any days that go by that doesn't entail taking a risk. Honestly, how many people have ever done 65 in a 55 MPH zone? (show of hands) Texted while driving? Ate while driving? Not worn their seat belt? These activities are exponentially way more dangerous than any careless drone flying. We all take calculated risks. You can even say that putting a drone up in the air is a risk. But these are the things we do because we enjoy our hobby. If people were afraid to take the risk, no one would fly. What I'm getting at is it is a bad idea to take unnecessary risks, such as I did on my doomed flight. I shared my story to serve as a cautionary tale of what could happen. Not to ask for people to condone or accept my behavior. However there are those who see otherwise who have been apoplectic with anger. They've taken this issue on highly personal level. My unsolicited advice to them? Since they offered me unsolicited advice - breathe. Breathe in. Breathe out. Deeply. Take a chill pill. And definitely don't drive or ride in automobiles.

End of rant.
 
UPDATE:

I have recovered my drone. With the help of member msinger AKA MavicHelp who was able to analyze my flight log and point me in the direction where the bird went down I was able to return to the scene and speak with the building management about the incident. I was honest about my mistake and described what happened. I was fully expecting them to be angry but surprisingly they were not. They were very understanding and cooperative. The security agent went onto the roof of the west wing (the building has the high rise tower in the middle with two four story wings on both sides) and there it was, right in the area msinger indicated it would be. Next to the air conditioner. Which, by the way was in the area that my friend and I covered in his drone but he did not think to go that far north or get close enough. Upon reviewing his video we did see it, but being so far away did not recognize it for what it was, tiny as the Mavic already is.

On the first search the security found the aircraft body and battery laying a few feet apart but the camera was missing. She went up an hour later on and found the tiny camera under the rooftop air conditioning unit and called me back to let me know she had it. Upon thanking her profusely and offering a reward which she graciously declined I was beyond stoked.

Now onto the good: the Mavic flies! Two props were broken at the tips but after replacing them the Mavic took to the skies without a beat. This thing loves to fly. Full functions, telemetry, altitude, speed, LED beacons, GPS, flight data all works as it should. Full range of movement. Arms are just fine. It folds and unfolds just like it did out of the box. The thing is built well. It did take an impact to the nose towards the starboard obstacle sensor and has a nasty scratch there. The top front cover is cracked near that spot. Starboard side front arm has a slight scuff near the red navigation light. Starboard rear arm has some very very slight scuffing to the bottom of it. Other than that, the rest of the body is absolutely flawless. Port side arms unaffected, heat sink on the bottom is mint. Maybe with the ability of the arms to fold allows it that much more "give" in a collision which could mean the difference broken an intact arm or a broken one.

The bad: Battery is destroyed. Like totally wasted. It looks like a twisted lump of plastic. It took a huge beating in the crash and got ejected. I can't imagine the foot pounds of energy that rippled through it during the sudden deceleration. The camera / gimbal mount has been detached from the aircraft body. The assembly looks like it might be fine, but the ribbon / connector has been torn. See the attached pictures.

Here's what happened: My Mavic lost RC connection as it flew around the building in question. It went into failsafe RTH. Without any way of getting input from me it initiated RTH and swung itself around and climbed from 252 feet to 90 meters (295 feet) which was the predetermined RTH altitude. As forward vision sensors were turned OFF at the time it did not engage them on the RTH. It dutifully made a beeline back to the home point before flying smack dab into the northwest/west side of the building. It fell about 250 feet to the rooftop of the west wing below. Member msinger went through my flight data and informed me of this and the recovered video from the drone collaborates with his information. He showed me a detailed satellite picture and highlighted the area where it went down. Thanks msinger! If you guys ever need help with located a downed drone please make him your go-to guy! He rocks!

I am going to work with DJI on repairing my drone as it appear that it does not have user serviceable parts at this time. I will keep you updated with the repair progress. Thank you to the members who offered support and especially to the one who offered me detailed help. It made a difference in being able to recover my Mavic and begin the repair process. Both of the Mavic and of my humility and bruised ego. I will most definitely fly smarter from now on.

Glad to hear you recovered it. Best to have RTH active if you're ever in an area that has tall buildings/objects...
 
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RTH active with the appropriate height setting that is.

Yes... Appropriate RTH height also needs to be set... However, I've never been really good at estimating the height of buildings/objects, so tend to go to max height for RTH in any case...
 
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