Yet another fly-away

French · Jul 18, 2015

Tonight I unfortunately had my first fly-away.

I was flying behind my house on a field, taking pictures of the sunset and the mountains. All went well for the 1st 5 minutes, and then suddenly I noticed that the drone would not stay in place anymore when I released the commands.

I immediately tried to bring the Inspire down, but before I knew it, it starting flying south at full speed. I tried to regain control by switching to ATTI mode, but it would not respond. After approx. 70m, the Inspire changed direction and well full speed north.

Since I live on a hill, I heard a big bang, and once I had climbed the hill, I found the drone crashed into a concrete wall next to a house about 100m away from my location. Drone is a pretty much a total loss.

At this point, I must say that I am mostly glad that nothing happened. Losing control of a 3kg drone that lives a life on its own is very scary. Particularly so, when I have had many flights before without issues, slowly gaining confidence after all the horror stories. I had been practicing ATTI mode as suggested in the forum as a potential recovery during a fly-away.

Before take off, I checked all the values and they seemed ok. During the initial 5 minutes, where I started with some test movements everything was fine.

Needless to say that I find it amazing that after releasing the drone 8 months ago, such serious fly-away issues are still around. It raises a serious question how secure the Inspire 1 really is and whether the drone is a hazard in non fully open space.

Curious to see how DJI will respond but I am not very hopeful, reading some of the other reports.

huppe · Jul 18, 2015

Ough,that's serious.Sorry for your loss French.As you say,hope that DJI will cover this.

Good luck

FangsCPO · Jul 18, 2015

So now for the many numerous questions that will. You say you check the values and they seemed okay. Are you sure?

sanderx · Jul 18, 2015

That sucks, big time. I can understand the feeling. I crashed a few expensive quads myself and it is gut wrenching when it happens.

A few questions: What were the mod values for compass and imu when you took off? Did you do a compass calibration when you took off (I am not implying you should have)? If not, where/when did you do your last compass calibration? When/where did you do your last imu calibration? Any power lines in the vicinity you were flying or potential wifi interference? When you mention that the inspire didn't stay in place after you released the sticks, was it going in circles when you released the sticks? (with the nose staying in more or less the same place with the inspire moving around the nose with increasing diameter of the circles) - this is called the TBE or 'Toilet Bowl Effect' and happens when the GPS and compass are not aligned and fighting each other. Do you have your antenna's on your transmitter standing up in an angle of appr. 90 degrees with your transmitter? Can you show the flight log of the flight (if it recorded it)?

Sorry about all the questions but it is hard to determine specifically what went wrong based on the description of your crash.

Having experience with DJI and their flight controllers (especially naza in the past) I rarely fly in GPS mode. Too many things are communicating with each other (GPS, barometer, gyro, compass, software) and they all need to be working in concert for everything to function well. With the inspire I always fly in atti mode and only use GPS mode for pictures or when I land but for extremely short period of times. Atti mode is fairly easy to learn and in my opinion every pilot should master this first before relying on GPS mode and even then I wouldn't rely on flying in GPS mode alone. I agree that it shouldn't have to be this way as DJI is advertising that it is safe to fly (ironically the app actually tells you to switch to GPS mode when you switch to atti mode) but as you said, GPS mode is just not 100% secure. Neither is flying solely in atti mode but it takes the risk down a factor in my pov.

inspireme2 · Jul 18, 2015

This is the reason why I jumped ship on my Inspire 1 that I just received yesterday but I decided to abort the idea and stick with my Phantom 3 Pro instead. There's way too many Inspire fly away stories floating around for me to feel comfortable with owning a $3K drone.

Same thing could happen to my Phantom 3 but $1200 is a lot easier to swallow than $3K.

sanderx · Jul 18, 2015

Not sure if there are too many fly away stories with the inspire. Remember, there are 422 followers on this forum and I have counted only a handful of flyaways and some of these might not be true flyaways. People who have successful flights don't always post their experience and I don't know how many inspires are out there but it must be thousands that do not have experienced a fly away. I have flown microcopter and dji phantoms and the number of reported flyaways was similar. Although I have never heard a satisfactory explanation on how and exactly when they happen but it seems to be a combination of GPS and compass conflict which occasionally happens on dji and other manufacturers' systems. I agree though that a flyaway/crash with a 3k drone is harder to swallow than a 1.2k quad.....

sirnikolas · Jul 19, 2015

I don't mean to question anything you've stated and I'm also truly sorry for your loss but I have to ask, did you have multiple flight modes enabled? I'm asking this because there has been many cases where pilots didn't know that this had to be enabled for the flight mode switch to work. Otherwise she's in full time GPS.

huppe · Jul 19, 2015

More reports of fly-aways will be reported as more people own a drone(quadcopter),but the more people will also have no problems flights.

damoncooper · Jul 19, 2015

Can you post a recording of your flight log played back in 1X speed with stick positions enabled? Perhaps we can help you figure out what happened.

Keithdennismahoney · Jul 19, 2015

had a similar situation myself today. I had completed a flight with the standard battery and had drained it. I flew in GPS mode and used a manual take off and landing. I use a Samsung Tab S and had recently updated the app to 1.2 and the operating system to lollipop. After putting in a new higher powered battery I used the auto take-off mode, after reaching the 1.2 meter height it suddenly shot off sideways crashing and rolling some 30 metres away. after checking the motors were ok, as I did not shut them off straight away, I tried to fly again and crashed a second time using manual take off, this time it was damage to the alignment of the props that made it go sideways. I reset the props to 5 degrees toe in and flew successfully 5 short test flights checking that all was ok.
interestingly each time I stated the DJI program it asked if I wanted to upgrade the app, which I already had, the firmware up until the last flight said the firmware was current. I tried to update the firmware at home but it was the May version which is the last version DJI has posted.
Up until now only 6 or so separate days flighting I have not had a problem.
Reading other post on different strings several pilots thinking that the upgrade may be the cause and DJI has not caught up with the OS upgrade changes????

m00se · Jul 19, 2015

sirnikolas said:
I don't mean to question anything you've stated and I'm also truly sorry for your loss but I have to ask, did you have multiple flight modes enabled? I'm asking this because there has been many cases where pilots didn't know that this had to be enabled for the flight mode switch to work. Otherwise she's in full time GPS.

I just updated my firmware, and the multiple flight modes has been disabled by default......
perhaps this happens to others at times aswell, perhaps they dont notice until in the air

French · Jul 20, 2015

I am still trying to re-engineer what happened during the fly away. At this point, I only have the flight path from my iphone. Device seems beyond repair, but may be DJI has some secret tricks.

Some key lessons learned though:
a) DJI disables multiple flight modes following firmware updates as was pointed out above (not sure how they can be so stupid to erase the previous setting given the quality of the firmware), but according to my flight plan, I could not enter in ATTI mode although I tried. MAKE SURE TO CHECK THIS AFTER EACH UPDATE OF FIRMWARE.

b) The Inspire accelerated to 17.1 m/s horizontal speed during its fly-away which is 40 mph. Given the weight of the drone, this represents a substantial risk for hurting a physical person or damaging property (Ironically I was actually relieved that the drone crashed in a solid house rather than something else).

c) The range before crash in case of a fly-away is substantial which raises the question about the safety of flying in open spaces within agglomerations (at least from my personal point of view).

d) The most scary part for me is that there is still no complete explanation by DJI of what really happens (IMU and compass calibration seem to be one, but I also found post http://www.phantompilots.com/threads/anatomy-of-a-dji-flyaway.42997/ that indicates more serious issues).

I will keep you posted on DJI feedback following the fly-away report that I filed.

m00se · Jul 20, 2015

S**T
I am on post 2 of the link above, and already it looks like that thread will unravel a world of scarey info.
The fact that he seems to have gathered info that can show an IMU lockup, thats not good,
I have had several problems with a P2 which looked like IMU problems. I also had the scarey moment last weekend, and an IMU lockup would somewhat fit in with what I saw....

I will continue reading and slowly S**t myself

inspireme2 · Jul 20, 2015

I fly a Phantom 3 Pro and I just recently ordered an Inspire 1. It came on Friday and I wanted to try it the next day to see how it flew compared to my P3P. I thought all night long what would happen if my newest $3K drone were to fly away or take a dive and crash in to the woods or drown in a lake.

I then chickened out and I boxed the thing right back up and UPS picked it up today. I'm not saying Phantoms don't also have these fly away problems but come on. It seems like you read more about Inspires flying away than you do with the Phantom 3 line.

It'd be bad enough if I were to lose my $1200 P3P, but I'd go freaking ballistic if a $3K device were to just fly away from me. Hell no.......

sanderx · Jul 20, 2015

I have flown phantoms and other quads with dji flight controllers as well as microcopter based systems (btw, they have had waypoint and autonomous flight capabilities 4 years ago) and the flyaways with inspires is not more than with other DJI and other manufacturers. I do agree that a 1k copter that crashes is (a little) easier to take than a 3k quad.

damoncooper · Jul 20, 2015

m00se said:
S**T
I am on post 2 of the link above, and already it looks like that thread will unravel a world of scarey info.
The fact that he seems to have gathered info that can show an IMU lockup, thats not good,
I have had several problems with a P2 which looked like IMU problems. I also had the scarey moment last weekend, and an IMU lockup would somewhat fit in with what I saw....

I will continue reading and slowly S**t myself

I assume you mean FC lockup/buffer overrun. Those are being taken seriously by DJI and FC stability is paramount to them I am convinced. Ian Wood demonstrated and illustrated a great example of a FC buffer overrun and resulting FC instability and crash using a P2. The Naza, A2 and N1 are in the same family and FC stability across the board is a paramount concern to DJI. Don't ask me how I know.

Hang in there. These are edge cases today but hopefully rarer than a blue moon tomorrow.

m00se · Jul 21, 2015

It seems logical that if you dont give the drone so much data to handle, you may well help avoid the problem,
IE they seem to happen more often when flying fast and dynamic......
So dont do it,(too much

Steve Perkins · Jul 21, 2015

This may have already been discussed, but has anyone documented the version (A,B,C or D) that these have been occurring with? Just curious if they are happening across the board, or if there are increased incidences on different versions of the Inspire.

The Editor · Jul 21, 2015

Steve Perkins said:
This may have already been discussed, but has anyone documented the version (A,B,C or D) that these have been occurring with? Just curious if they are happening across the board, or if there are increased incidences on different versions of the Inspire.

Hi, welcome to the forum.

The version differences are not electronic - they are mechanical.
A-B Change of carbon fiber weave
B-C Supply of QR props
C-D Slightly redesigned landing gear mechanism (2 parts instead of 4)

Wormwood · Jul 21, 2015

Moose you maybe on to something... It's always been a mfg's MO to source a processor that has JUST ENOUGH power to manage all the calculations. However, they never consider ALL available inputs/sensors will be active for any period of time & there's no regulations or minimums. Finally, with UAS moving from a recreational hobby to an occupation, this previous mindset is still there from the mfg. & this increasingly simplfiied operation of a UAS has got to be lowering the proficiency of the avg. operator. It's more common to see erratic operation styles on the flight data from these flyaway's people post, before they are said to have lost control. They're treating the inputs like on/off switches, no proportional though of control. It's only 0% or 100% or close to it.