I finally bit the bullet and ordered the 3DR kit. #excited
I should preface all of this with the fact that I'm not a hardware guy, software guy, r/c guy, hax0r extraordinaire, FAA commander, or anything that would make me particularly qualified -- I ordered the kit, followed the instructions, and happen to have an experienced quad flyer friend to bounce questions off of.
To start, my experience with the ordering system was lacking -- multiple kits "in-stock" but nothing could be added to my cart because one of the items in the kit was not in-stock. I could see this being an issue if it were a major component, but it was the velcro battery strap. So if you cannot delay shipment until said part arrives, and you won't let me add the kit to my cart, then you really don't have any in-stock.
Kit arrives and I spend the next two and a half days or so building the 3DR per the instructions in the wiki. It wasn't really all that difficult, just a lot of tedious work - checking, double checking, oops and fixing, etc. Issues that I had included the instructions not matching the hardware I was sent. Cables weren't the same colors, parts were off, etc.
After the main frame assembly was complete there was a very noticeable "arch" on two of the arms. If oriented in "plus" mode instead of "x" mode you would notice that the left and right arms were both angled backwards by several degrees, while the fore and aft arms formed a straight line in relation to each other. The left/right arms had to be measured and drilled out a bit to make them straight. Poor QC imho.
It was also interesting to see that 3DR was shipping bullet connectors as from my research they are notoriously sketchy. Not that it's a show stopper, but "sketchy" is not a word I want to use for any components going into a fairly expensive flying device. Replaced all the bullets with dean connectors which seem to be pretty stable. (also per the rec of my quad flyer friend)
The configuration of everything seemed to be pretty straight forward with no major or noticeable glitches. Once the beast was built it was time to see if it would fly!
Flying started slowly until I could get a feel for how this thing works. I can say that after a few minor adjustments it was picture perfect! Hovered well, responded well, and seemed to generally be a rock solid performer. I was definitely stoked to fly more. I drained one battery in testing.
Day 4: I head to the quad flyer buddy of mine's house and we head out to a HUGE field to play around and for me to learn a bit more. Drained another battery and everything seemed grand - and then...
After putting in the second battery (3rd battery that's ever been used) I start noticing a little glitch -- the controls don't seem to respond, but only for a second. The quad is hovering nicely, bank right, nothing - being a newb I'm not sure what's going on as everything else has been spotless. Bank right again and we're back. This happened a couple times in various spots, but nothing major.
We then do a vertical assent, which I've done a couple previously, but this time was different, much different. I "gas" it to probably 75% throttle and the quad shoots straight up, fast, I let off the throttle and nothing happens. The quad continues to climb and no controls will work! There was a 2-3mph cross wind and the quad climbed and was blown sideways FOR MILES. A more or less fresh 2650mah nano-tech battery carried this bitch further than I could see it until it was nothing more than a black dot across the grey sky. Nothing worked, nothing stopped it. Gone.
I have no means of locating the craft let alone troubleshooting wth happened - could it have been a bad board? bad radio? software malfunction? short? I'm not trying to lay blame on 3DR or anything, but there are a lot of assumptions made in the assembly instructions, stuff that's just plain not there, and if I didn't have an experienced pal assisting there would have been a lot of unanswered questions. Heh, at this point there still are.
So my take away from this is - WTF. I completely lost the quad I just paid 600$ for, spent 2 days building, have flown twice - barely, and have no clue as to why it decided to full throttle to the stratosphere. There appeared to be zero issues with any of the equipment, all fresh batteries, and much to the bewilderment of my experienced friend who commented that he's never seen that happen before.
So the two flights I got out of this device were awesome and I was told it was handling very well and looked spot on. Irrelevant at this point I suppose as I don't even have a handful of busted parts to scavenge from. I lost the entire craft, a brand new battery, and radio gear.
I would like to try out the geofence on my quad, but I can't figure out how to get the .hex file onto the APM2.
Seriously though, getting back to the original poster minus all the other opinions, the facts seem pretty clear. The accident was caused by a failure to set proper "failsafe" settings into the radio receiver, and then further, lack of testing with props off to ensure those settings worked with the APM. In other words, follow the failsafe setup instructions from the radio's manual, then test that under live conditions with the props off by removing the transmitter's antennae and doing a range check and/or bring the aircraft up to throttle and then turning the radio off. Every good radio I have ever owned said to do those exact steps (JR, Futaba, Airtronics, and of course Spectrum).
Further mitigation (again, not a fix for the above steps which are REQUIRED), is to use the new fencing code variants and ensure you set them. The biggest concern here is that you the pilot must be in control at all times, and further, have been trained and practice and know what to do in the event of major radio glitch or system failure before you ever bolt on the props and try to fly. There simply is no excuse to blame this on the APM. It's meant for pilot assistance to help with tedious or difficult tasks such as loiter, altitude hold, moving to set waypoints, all with the pilot in constant radio contact and control. In no way was the APM or code ever designed to "save the aircraft" or "prevent a crash". If you think that's what it does or should do, then you need to be looking at a much more expensive redundant system and sensor package that includes some sort of obstacle and collision avoidance-something we haven't even thought about on the current APMs. Without collision avoidance, any of the measures described as safety features such as RTL, RTB, Circle at altitude (loiter), have the potential to actually cause a crash, not prevent it with fixed objects such as buildings, light poles and power lines and maybe even people! If you are not in control, then we must assume the worst.
I'll add that further, this is why the brand name radios cost more. It doesn't mean they are fool proof, just that they probably are a better radio since they are often certified by the FCC and also tested by groups such as the AMA. Flying a $600 aircraft with a less than $200 radio system or non-name brand might be expected to exhibit problems like this with untested failsafes, lack of radio interference rejection and a whole host of other issues. Cost is not the most important consideration, but you really do get more for a name brand product.
I cannot stress enough that the builder is responsible for the safe operation of the aircraft. You must test and know what it will do before you put it in the air and put both yourself and others at risk from an out of control machine.
No doubt this sucks to have crashed and LOST the aircraft, but at the same time, for other new flyers, this is important info to take away.
Both of those pages need to be updated. I could use some help, if anyone wants to help writing some content for those pages, to get it done sooner.
I have not seen a stock 9x do failsafe. The PPC/PCM manual entry might be a red herring. But maybe I'm wrong...
As far as I know the only way to get failsafe to work with the Turnigy 9x is to use the FrSky module and receiver (or similar?).
I put a plane into the bay because the 9x lost connection. Now I'm setup with the FrSky and the plane will RTL on signal loss (just programmed the receiver output to set RTL mode and 50% throttle on signal loss). Also the radio seems to be less glitchy with FrSky. Worth the investment.
With the Aurdocopter it's a bit more tricky. I can't always trust that RTL would actually do the right thing. Still in the midst of tuning things that loiter would actually be reliable instead of just flying off to a unknown destination. Maybe 25%-30% throttle would be the best setting for now. -> Fall down but not as fast as gravity would dictate.. but it would start to mow the lawn after impact...
I know this thread has finally died down, but I wanted to post a relevant thread for anyone who may find this one in the future. It would appear as though the Turnigy 9x was NOT to blame and that the fly-away was directly caused by the APM.