High Altitude Disaster

[Warlock]

I have had my F550 WKM about a week. Had Robert at DJIUSA do the build. This is my 4th quad type aerial platform, of course this is a hexa. All the others were expensive junk. I was so impressed with the way this F-550 flies, and it was really starting to give me some confidence. Took it out in the front yard and did a little flying. http://www.youtube.com/watch?v=qHxPfpuQno4

I made up a set of led lights with its own battery and switch. http://www.youtube.com/watch?v=AGdp_kfWuEs Man I was very pleased. So I hooked up my FPV gear that I have had waiting for something worthy to put it on.

View attachment 5884 This morning I got up early to beat the wind and heat here in Texas. I was running a freshly charged Traxxas 8.400 mah lipo which can deliver some 12 minute flight times with ease. I did test out my FPV gear and it worked great but I wanted to do a little "high altitude" flying before I did more FPV, the FPV transmitter ran off its own battery. After landing, I rechecked everything and it was more than good to go. Took off and flew across this field near a church and started climbing. I was about 500 feet or more away.

I started getting a bit nervous because about 100 feet up was my record, and I was WAY past that! Hit return to home, and figured it would save the day I know it worked as I tried it at least 5 times prior to this session. It climbed another 60 feet and went above the cloud base and I lost sight of it. Not TOO WORRIED I expected it to head back in my direction, but the sun was in my eyes, and I just saw a tiny spec in the sky which was passing me by over head. I worried that it lost me and I tried to walk with it all the while hoping that soon it will lower its self... It didnt. I didnt because it was a BIRD!!!!!

Now I am FREAKING OUT!!!! No where in the sky was my 550, and with every bit of the gear I paid dearly for. several minutes go by, and you know that all is lost really lost. I tried turning off RTH and very slowly lowering it even though I saw nothing. In disbeliefe, I stagger back to the parking lot I took off from, and there was my F-550 scattered in many pieces totally destroyed! :dejection:

I dont know exactly how it happened, but I guess my switching off RTH and back on confused the WKM system. So it just hovered way up high directly over the spot it took off from till the battery finally died and then it dropped from the sky. And the really crappy part of it was I got no video of the fall, because the Go Pro battery quit on me. I saw in my goggles doing FPV that the battery was over half spent, would have been some good crash video.

http://www.youtube.com/watch?v=a6J-JS2nfXI View attachment 5885 How high up do you think it was?

 

[DesJardins]

Damn, sorry to see that!

 

[Droider]

AHHH I hate seen these posts. Really sorry for your crash. Did you have a Lipo Alarm on it? They are the best investment anyone can make. I know you ost it in the cloud but you would have at least heard it as they are super loud. They also help finding them if they do come down. Hope your confidence aint shaken to much. Hope you get it back up soon.

Dave

 

[kloner]

goodness, that thing smashed into pieces

in your video i'd guess you were in excess of 400'
this is 550'

at 1:00 to 1:03 is 2x 20' boats on the sand bar, the pano was the vista

man, not sure it matters, but when your gonna use a gopro for a live feed fpv cam, you have to more than make absolute sure you just pulled it off a charger. if when you turn it on ever and it doesn't have all three bars showing a full charge, i wont even leave the ground. i go as far as use a phone charger in my car in between flights and on the way to the spot.......... it's the only thing having a dedicated cam does is somehting like this you'd have been able to look and know where it was and what was doing

sucks dude, sorry to see it

 

[Dewster]

1: that's some serious altitude. The F.A.A would be quite bothered by its height.
2: nice view. I'm guessing 2 thousand feet.
3: RTH will fly back to where it was launched and begin a slow descent to land. You need to make sure you have enough battery left for its auto descent.
4: You have to switch modes of flight to regain control of your craft (RTH to GPS or Attitude mode). Make sure your throttle setting is at half so that it hovers vs falling out of the sky.

RTH works. I always hold my breath and pray that it functions as intended.

 

[FerdinandK]

Sorry to read about your crash.

With a multi you can climb fast (depends on the multi, but 6m/s easily possible). If you climb fast, you have to be able to descent fast, and that is only possible in manual mode (with dji-FCs). So when flying fpv (even if Video is lost) out of a stable hover, just switch to manual, lower the throttel channel, an move the elevator forward (a bit) for a second. The copter will come down in a stable fast forward descent. If you do not trust your copter do this for 10s, switch back to atti again and repeat. The point is you should (have to) exercise this before. Typically the signal of the Video recovers when you come down, since most antennas have a weak spot on top. In every situation the most important thing is, that you have to know what your copter is doing (with or without video), this means you have to know the copter, which needs time for training.

It is also good if you have a plan what you want to do during this flight before you take off.

best regards

Ferdinand

 

[Bison52]

I'm just guessing here but some things I have noticed that could be in play here. First, the descent on RTH seems to be very slow, even from a relatively low altitude it has seemed to take a long time to land.

Second, descending straight down seems to be a difficult flight regime for a multi and uses a remarkable amount of power.

So I would guess that the RTH was functioning within its parameters but in the slow automated descent of RTH, from an extreme height, it just ran out of juice before it ran out of altitude.

 

[Droider]

Looks like the new firmware addresses the slow decent. Kilby has just posted the new features.

 

[kloner]

Sorry to read about your crash.

With a multi you can climb fast (depends on the multi, but 6m/s easily possible). If you climb fast, you have to be able to descent fast, and that is only possible in manual mode (with dji-FCs).

Ferdinand

In the video i posted it went above his to exactly 550 feet in 1 minute and came down in :40 seconds all in atti

 

[FerdinandK]

That is true, but in manual mode you can come down in 10s. I just want to say, as backup, you can much faster (up, down, forward) in manual mode.

best regards

Ferdinand

 

[yeehaanow]

Sorry about your crash! This is a good example of why a spotter is helpful. I know it's hard to find someone sometimes though.

 

[kloner]

if your in atti mode over 60 degrees it'll shut the motor off so be carefull relying on switching back and forth and make sure to tape your memory card in the go pro so we can see the film

 

[Bison52]

Well I should have watched all the video all the way to the end. No descent to that, just hung up there till it ran out of gas. It might have started its low battery failsafe descent if you had it set up but no way it could make it to the ground on that from that height.

I agree with Dewster, the FAA won't be happy at all if they see that.

 

[Warlock]

goodness, that thing smashed into pieces

in your video i'd guess you were in excess of 400'
this is 550'

at 1:00 to 1:03 is 2x 20' boats on the sand bar, the pano was the vista

man, not sure it matters, but when your gonna use a gopro for a live feed fpv cam, you have to more than make absolute sure you just pulled it off a charger. if when you turn it on ever and it doesn't have all three bars showing a full charge, i wont even leave the ground. i go as far as use a phone charger in my car in between flights and on the way to the spot.......... it's the only thing having a dedicated cam does is somehting like this you'd have been able to look and know where it was and what was doing

sucks dude, sorry to see it

Yes sir, I was not using FPV when this happened though. I still would have at least appreciated the final crash clip. It started its hover at altitude and sat there for like 7 minutes and maybe longer but the camera went dead I dont know how much longer it was up after that, I was chasing down a high flying bird.

 

[Warlock]

1: that's some serious altitude. The F.A.A would be quite bothered by its height.
2: nice view. I'm guessing 2 thousand feet.
3: RTH will fly back to where it was launched and begin a slow descent to land. You need to make sure you have enough battery left for its auto descent.
4: You have to switch modes of flight to regain control of your craft (RTH to GPS or Attitude mode). Make sure your throttle setting is at half so that it hovers vs falling out of the sky.

RTH works. I always hold my breath and pray that it functions as intended.

Thank you, this is info I sure could have used this morning. I did not realize I needed to switch to atti mode. And it could have gone up and down a few more times. In the video, it begins its long constant hover at 3 minutes 30 seconds and the camera went down at 11.08 minutes and longer till it quit. So it was in a steady hover at altitude for 8 or 9 minutes, more than plenty of time to come down if I had done the right things. In addition, had the battery voltage safe guards been set up I would have found my baby sitting in pretty on the parking lot after it auto landed. But Robert does not like that feature and did not set it up on my F-550. Not blaming him for my mistakes, but I asked for this and did not get it. He told me that it shortens flight times un nessesarily and its better to just fly for 5 minutes or so and land. Most of the time that would work for me just fine, but in this case Im SOL :upset:

 

[Warlock]

Well I should have watched all the video all the way to the end. No descent to that, just hung up there till it ran out of gas. It might have started its low battery failsafe descent if you had it set up but no way it could make it to the ground on that from that height.

I agree with Dewster, the FAA won't be happy at all if they see that.

Well it sat up there in that spot for over 8 minutes. How high up do you believe it is? It could have landed and gone up again a few more times if all I did was go straight up and straight down. Notice the time it started the hover? 3 minutes. The camera went dead at 11.8 minutes, and no telling how much longer it hung up there. As well the FAA have better things to do than worry over my hexacopter.

 

[hjls3]

As well the FAA have better things to do than worry over my hexacopter.

yikes. that is a bit scary. as a private pilot and MR user, please consider this statement further. One bad accident and none of us will be flying MR's. Not to mention the terrible accident that could happen. Keep it under 400', please...and sorry about your crash.

 

[Stacky]

Sorry, Im going to say it but someone has to. What on earth were you thinking going so high near a motorway and near residential housing?. Also did you inform local aviation you were going so high?.
Do you have any idea the sort of danger you could pose to people if you have a problem that high up?. You are lucky the multi landed on the car park. If you had landed on the motorway you could have caused an accident that could have resulted in people being hurt. The FAA are there for a reason, can you imagine the consequences of some sort of light aircraft hitting your multi?. Where I am if you want to fly above 400feet you have to notify the local air traffic, for a really good reason.
Why on earth did you keep climbing in to clouds?

The FAA NEED to be worried about people like you. Ignoring any regulations or laws the personal responsibility of making sure ones actions dont have the chance to hurt or endanger others surely must be a consideration?. These multis crash, be it human error or mechanical issues and when they come down they can do some damage. Your problem is proof these things fail. You just got lucky you only smashed your own machine. I have had a multi fly away from me because of lost radio signal which in turn was my fault. When it flew away all I was worried about was it hitting someone. Your only worry in your first post was the loss of expensive gear.

 

[copterstudios]

I have to comment on this one and the FAA comment..... I am a strong proponent with this industry but please stay below 500 feet. I fly in a full size helicopter everyday. It appears you were at 1500 to 2000 feet. Our minimum enroute altitude is 1000 feet. If my helicopter were to hit that f550 and we usually fly around 180mph it would have gone through the cockpit and slammed into the pilot. Without a pilot we will not make it down in one piece..... We hit birds frequently when we fly and they seem pretty soft however a goose will fly into the windshield and possible injur the pilot. Anytime we have a bird strike and they happen frequently we have to report it and do a visual inspection. So, the FAA will care but not really until there is an issue with a full size aircraft.

 

[naturecannon]

Curious to see if your WKM still works. Think your SOL for sure, fall like that has got to rattle the insides good. 60' drop and hard thud on hard dirt finished the internals of my Naza off :upset:. Never budged off bottom mounting plate and mounting tape of the 550 nor a scratch on it, the outside anyways! Already purchased new one but will be sending borked Naza in for repair soon.

Glad I read this thread, always wondered the height limit before dangerous to other crafts. Curious, how would one even begin to estimate 400'-500' with no real reference point or objects sorrounding??