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Crash story from Sunday

Discussion in 'Cinestar 8' started by Dave King, Jun 11, 2013.

  1. Dave King

    Dave King Well-Known Member

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    I had a pretty bad day on Sunday!!! I had a major crash and the carnage is very extensive. I was having a really good day of shooting. I started early in the morning and had 11 different flights over 3 hours. I was taking stills around the city to include a portfolio for my website. I was also on the last shot of the flight where I just wanted a higher prospective of the the shot I wanted. I was monitoring battery voltage with the graupner lady and everything was good. I was probably going to bring her back in the next 30 seconds but it just fell out of the sky. I had a spotter on hand that I was in radio contact with and traffic-people were very very light at this time of day (thank god). I was moving the copter around in coordination with the spotter under the copter radioing me back instructions. I was able to see the copter line of site but I couldn’t really see the orientation very well at this distance but I did have FPV (no OSD). Then I just saw the bird start to plummet and tumble. I knew there was no saving it so I cut the motors. I will never forget the feeling of seeing the bird fall out of the sky and not knowing if it hit someone, if it landed on a building and the batteries burst on fire, did it cause property damage, or did someone record this on a cell phone and going to be all over the internet? All these things were rushing through my mind when I saw it drop 400 meters away. The spotter was there over it when it fell and it had a huge violent impact. After it crashed he got scared and ran (nice guy huh). I was quite far away from the copter (about 400 meters) so I had to go find it on my own. It was like a nightmare. When I got up to it the police were already there and helped me out considerable. They were very cool about it!!!!!

    So what caused the crash?
    Conclusion: Pilot error. Pilot arrogance, and pilot being over confident. One of 2 theories happened.

    Theory 1 : As I was descending the copter didn’t’ appear to be descending much to me so I kept reducing the gas all the way to the point that I reduced it all the way and I believe the motors lost enough speed and stalled.

    Theory 2: When I watched the copter line of sight I had a false visualization that the copter was dropping and I cut the motors based on a false visualization of what I thought was happening. There’s really no way to tell by the GPX files.

    Either way I certainly learned about flying at farther distances and how it can give you false visual indications. I thought the copter wasn’t losing much altitude and thus I kept giving it less gas to descend to the point it must have stalled. This really hit me in the gut and made me re-evaluate what I’m going to be using the copter for. This crash could have completely avoided had I just moved closer to the subject of the shot. By the time I got to this location I was starting to get fatigued after 3 prior shoot locations and 4 hours of flying. Looking back at it now honestly and opening I was being lazy and letting how I physically felt alter my safety decisions. I didn’t want to have to worry about packing back up, moving the car, and finding another parking space. I had been flying for 5 months without any crashes and I was feeling a little too confident. Now I always have this to fall back on next time I think about making shortcuts.

    I plan on learning from these mistakes and I’m going to modify where, what, and how I fly. I guess this is all like being a kid again where you parents warn you not to touch something and you know remember your parents telling you not to but you ignore their warnings and then get burned, stung, or worst. Once you get hurt, you don’t make the same mistake twice. Now I always have that “feeling of horror” to fall back on to ensure that I follow every safety precaution possible. I know that it will be impossible to avoid another crash in the future of some magnitude. But at least I will give myself the best odds to have the safest shoots possible, and minimize damage.

    So far the damage goes as follows
    Power distribution board (have back up). PSD is torn up very badly, I wont even trust keeping the BL's for backup because they could have hairline cracks.
    New ACC sensor for the flight control board – flight control board needs tested (have back up if needed)
    New top center hub plate
    New bottom center hub plate
    3 450mm booms
    Not sure what to do about the motors just yet because of the way it impacted the ground. I need to replace at least the propeller mounts
    Gimbal star plate that bolts to the cinestar
    Battery plate, standoff's, and flying rabbit receiver bracket
    GR24 receiver
    GR16 receiver
    3 smaller 125 booms on the gimbal
    1 radian
    GPS board (have backup)
    1 servo (have backup)
    Pan pulley and belt (have backups)
    Iftron 5.8 transmitter
    New Sony 760 camera (have square trade warranty- keeping fingers crossed)
    Top boom connector for the gimbal and downpipe

    How you see the CS8 below is exacty how it laneded.

    DSC_0707.jpg

    DSC_0714.jpg
     
  2. Steve Maller

    Steve Maller UAV Grief Counselor

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    OMG that is horrible. Did you get anything off the microSD card? A GPX file might have more clues as to how this happened. So terribly sorry for this. Ouch. :(
     
  3. Dave King

    Dave King Well-Known Member

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    HI Steve

    Yeah I sent the GPX files to a couple of senior advisors :cool: who were able to reconstruct what went wrong. Definetly pilot error due to loss of orientation because I couldn't see the copter descending at the rate it was from my faraway vantage point. The copter was responding correctly to my initial responses to the decrease in throttle but I couldn't tell from my vantage point so I kept giving it less and less gas. The GPX files show me cutting the motors right before impact. Either that happened or I had an illusion that the copter was falling when in realty it wasn't and cut the motors. I plan to live and learn and be a better pilot from the experience.
     
  4. Dave King

    Dave King Well-Known Member

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    when the copter impacted the ground it landed on its top side and hit so hard that the top of the studs on the propeller mounts got distorted. ON 6 of the motors I had to cut the studs down with a cutting wheel to get thet nuts off to remove the props.
     
  5. Tyler Olson

    Tyler Olson Member

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    Nasty. Glad everyone was fine and you found your copter. It is certainly a good reminder that we need to fly in a manner which respects the fact that the copter could come crashing down at any time.
     
  6. Sebastian Meredith

    Sebastian Meredith Active Member

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    :eek: wow that's hectic! I probably would have lost my lunch right there on the sidewalk!!!
    Nobody likes picking up their CS with a dustpan and a broom ...

    Did you every find your spotter? or is he still running ...
     
  7. Tyler Olson

    Tyler Olson Member

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    I was wondering the same...
     
  8. Dave King

    Dave King Well-Known Member

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    Yes, but only after I found it and only after he saw that the police were not upset. I was talking to the police offer who nicely picked up the broken Sony 760 and put it in his vehicle and then out of the blue he comes over walking like nothing happened. I won't be using him again.
     
  9. Sebastian Meredith

    Sebastian Meredith Active Member

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    Perhaps we should train our spotters to be catchers as well ?!? ;)
     
  10. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Do you have video from the crash? Sorry to hear about it! Are you planning on rebuilding?

    Josh
     
  11. Dave King

    Dave King Well-Known Member

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    I will admit that I have not trained the spotters I used very well other than to just give me observations back and to alert people when its over them. I need to give more training as to how to handle situations and be more assertive of feedback for me. I also need to train them on how to hold up traffic or hold me up if there is traffic.

    One question I have people that use spotters how do you communicate? Cell phones? 2 way radio? Personally I don't like ear buds and find them very annoying. I have been using motorola radios that work "OK" with some dropouts.
     
  12. Dave King

    Dave King Well-Known Member

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    Thanks Josh

    Yeap I already got the wheels rolling. Replaced the bad BL on my spare PDB, sent both my Flight control boards already shipped back to QC for ACC mode and have them fly the boards, sent the camera to Square trade and ordered everything else this morning. My goal is to be up and running in 3 weeks going over everything very thoroughly.
     
  13. Jason Toth

    Jason Toth Active Member

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    Use your telemetry, get OSD and 2 video downlinks (FPV and camera) so you can get oriented! Worst case you hover at 50% till you get your bearings right. Sorry to hear you story but glad no one got hurt!
     
  14. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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    Pilot error is very real we have to remind our selfs of this all the time, sorry for your loss I have been there my self in the ocean, over some surfers, kopter too far, to low, I rely too much on FPV, got exited and distracted for the great shot I had, and ......down it went, in my case also no damage to any one, I hope you are flying soon, at the end its just a kopter, soo glad it did not harm any thing or any one
    Thanks for sharing your particular experience with all of us
     
  15. Shaun Stanton

    Shaun Stanton Active Member

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    Dave, anyway we can take a look at your GPX?

    To echo the other comments, I would highly suggest getting the smart OSD. That OSD you get an a small marker on the side of the Altimeter to see what the descent rate is. I don't know how I would be able to fly long distances without aircraft instrumentation. Without it you are flying blind.
     
  16. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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    Hi Shaun I dont have a smart OSD I been thinking about it my question ( if I may in this tread) whats involve in the installation I understand that it is not a plug and play what is your recommendation on the OSD
    I have MK electronics at the moment
    you know thanks to Dave and others on sharing their unfortunate events it will help many others make the MR world safer
    Thanks
     
  17. Gary Haynes

    Gary Haynes Administrator
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    JOse the best choice is the SmartOSD. Basically plug and play. Sits on top of the Navi board and connects with three cables. One 2x6 cable, a single servo wire if you want to be able to switch screens and video in and out from your FPV camera. QC sells them. Relatively easy to setup the screens though the manual is a bit weak.
     
  18. Shaun Stanton

    Shaun Stanton Active Member

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    The only thing about that is not as plug and play is integrating the video signal properly, especially if you are like me and use a separate battery to power the video transmitter and an FPV camera. With this setup you have to make sure all the ground wires are interconnected with the appropriate devices.

    At a minimum all of the video signals have to share the same ground. For some reason this is not done on the OSD circuit board, probably because there was not enough real-estate on the board available. This is where the wires can get messy you have to splice wires and solder and shield them properly.
     
  19. Gary Haynes

    Gary Haynes Administrator
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    Shaun I also power my FPV separately for the video side. So FPV, Smart Video, Iftron are all on the separate power and ground. Only place I have that is picking up any system wide ground is the video switcher (Servo connect to the FC board) and of course the 2x6 and servo control pin on the SmartOSD?

    Did you find that using shielded cable for the video made any difference? I tried it and just use the yellow video connector wire that came from Iftron.
     
  20. Shaun Stanton

    Shaun Stanton Active Member

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    I may have misspoke the individual grounds for the video OUT and IN can be separate to the corresponding device.

    That's right If everything is powered off of a single battery then the grounds will naturally be interconnected. I had the Iftron 5.8 a while back, if I remember correctly that one sent the power from the battery to the video camera. My setup is a little different now because I am using a 900MhZ TX to an HK board camera and small 1 Axis gimbal. With that one I had to do more splicing of wires to make sure the battery was being connected to both systems properly. The board will provide a common through the 6 Pin cable to the NAV.

    So the setup is

    6 Pin to NAV DEBUG port
    Video in is comming from the camera (separate ground and signal)
    Video Out to the transmitter
    Battery connected in parallel with the TX and camera if using the same LIPO to power the camera.

    That should work and is fairly straight forward. In fact I don't think ever used the ground signal wire to the FC because that was already being provided by the 6 pin. I don't have mode switching anymore since I do not enough channels on my DX8 to do it. I was using my round knob to switch the modes prior to installing a gimbal. Now that knob control's the nose camera tilt through MK FC.



    Not really. I have all of the cables shielded using that "Chinese Finger" Stuff than shrink wrapped in clear plastic. I do find that it does help keep some noise from bleeding into the video signal, as well as it does seem to do a good job keeping EM from interfering with the compass.
     

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