Today's second test flight session of the season had some very interesting things going on in it...
1. Large greyhounds pursuing craft wherever it went in sky, making landing much more exciting than usual. Solved that.
2. Helicopter appearing over the treeline at 400 ft or so, and vectored directly at my craft. Solved that too.
3 Mysterious drop-from-sky type event just after take-off with 3rd pack, and it is that one I am documenting here...
It was the 3rd flight of the day, and the previous 2 had completed as normal, with impeccable behaviour from the H at every stage of the way.
I had loaded up with the 'red' battery pack, a Yuneec original, which is being used for the first time for its 3rd season after a slightly problematic charge with a balance charger that died in the process, and would balance charge to 4.2v on 3 out of 4 cells, then just as the final one crested 4.2, would reset it to 3.7, and then spent an hour trying to get back to balance. Having spotted this, the charger was retired, and a new B6 V2 charger was acquired, and plugged into that battery pack in order to try and rescue it. It balanced in 40 mins, and when checked with a separate voltage checker reported 4.17v across all cells, which gave me 16.7 total, which I thought was commensurate with the age and cycles on the pack.I expected about 8-9 mins flight down to 14.6v.
All pre-flights passed, we had 18 sats acquired, and launched perfectly. I climbed to 5 ft to clear the worst of ground effect, then paused to adjust some camera ISO settings. At this point, ready to do my planned video mission, I bumped her to 12 ft high, and dropped my right hand to raise the landing gear. As i did this I gave a firm increase in throttle to 'launch' out of hover with purpose. At this point, the craft began the ascent, then stopped, and pretty much fell out of the sky. I had not yet raised landing gear, so we came down on soft heath ground / sand, and the gear took the hit, protecting the camera from damage, and remaining unbroken itself luckily. However now I have a craft with all motors still spinning, bouncing up and down on the ground, and looking like tipping is imminent.
At this point I am heavily down-sticking (to try and keep it down and stop it bouncing) and simultaneously trying to red-button it, and what seems like a seriously protracted 5 second later motors stop, and we have a craft made safe and landed without damage.
So this has gone as well as I could hope events like this might end up, and I recorded what my screens were saying, powered down, examined the battery, and went over the craft looking for damage, which I didn't find. All motors continue to spin correctly when powered up (unlaunched) subsequently. Pack voltage was not doing anything unusual according to St-16.All motors slightly warm, but none hot. Battery emerges un-puffed, but hot.
After 15 mins rest and further inspections, I tried my remaining 2 packs, and commenced hovering at 1ft for an extended test period, then began a series of gently increasing ascents and descents, all of which were without further incident. For the last pack of the day, which was a virgin pack (also re-balanced by the new charger) I did go a little higher, but being very cautious kept her under 30 ft for nearly the full duration, and did some gentle circles to further test things. Everything was fine after 4 mins of that, so I risked a small climb to 60 ft just to grab the sunset, which was looking very attractive at the time.
I have not yet retrieved the telemetry, but obviously that is my next plan. I need to get the Telemetry reading app (forgive me I can never remember what it's called) installed on this new Win 10 machine, but will try that tomorrow. Am I right in thinking I have to run that in Win 7 compatibility mode, but that if I do so and use the Yuneec USB cable specifically, I am expecting that to work right ?
So anyway, there is my initial account before I forget it ! More to follow as investigations continue...
AJ
EDITED in light of new evidence so report remains accurate.
1. Large greyhounds pursuing craft wherever it went in sky, making landing much more exciting than usual. Solved that.
2. Helicopter appearing over the treeline at 400 ft or so, and vectored directly at my craft. Solved that too.
3 Mysterious drop-from-sky type event just after take-off with 3rd pack, and it is that one I am documenting here...
It was the 3rd flight of the day, and the previous 2 had completed as normal, with impeccable behaviour from the H at every stage of the way.
I had loaded up with the 'red' battery pack, a Yuneec original, which is being used for the first time for its 3rd season after a slightly problematic charge with a balance charger that died in the process, and would balance charge to 4.2v on 3 out of 4 cells, then just as the final one crested 4.2, would reset it to 3.7, and then spent an hour trying to get back to balance. Having spotted this, the charger was retired, and a new B6 V2 charger was acquired, and plugged into that battery pack in order to try and rescue it. It balanced in 40 mins, and when checked with a separate voltage checker reported 4.17v across all cells, which gave me 16.7 total, which I thought was commensurate with the age and cycles on the pack.I expected about 8-9 mins flight down to 14.6v.
All pre-flights passed, we had 18 sats acquired, and launched perfectly. I climbed to 5 ft to clear the worst of ground effect, then paused to adjust some camera ISO settings. At this point, ready to do my planned video mission, I bumped her to 12 ft high, and dropped my right hand to raise the landing gear. As i did this I gave a firm increase in throttle to 'launch' out of hover with purpose. At this point, the craft began the ascent, then stopped, and pretty much fell out of the sky. I had not yet raised landing gear, so we came down on soft heath ground / sand, and the gear took the hit, protecting the camera from damage, and remaining unbroken itself luckily. However now I have a craft with all motors still spinning, bouncing up and down on the ground, and looking like tipping is imminent.
At this point I am heavily down-sticking (to try and keep it down and stop it bouncing) and simultaneously trying to red-button it, and what seems like a seriously protracted 5 second later motors stop, and we have a craft made safe and landed without damage.
So this has gone as well as I could hope events like this might end up, and I recorded what my screens were saying, powered down, examined the battery, and went over the craft looking for damage, which I didn't find. All motors continue to spin correctly when powered up (unlaunched) subsequently. Pack voltage was not doing anything unusual according to St-16.All motors slightly warm, but none hot. Battery emerges un-puffed, but hot.
After 15 mins rest and further inspections, I tried my remaining 2 packs, and commenced hovering at 1ft for an extended test period, then began a series of gently increasing ascents and descents, all of which were without further incident. For the last pack of the day, which was a virgin pack (also re-balanced by the new charger) I did go a little higher, but being very cautious kept her under 30 ft for nearly the full duration, and did some gentle circles to further test things. Everything was fine after 4 mins of that, so I risked a small climb to 60 ft just to grab the sunset, which was looking very attractive at the time.
I have not yet retrieved the telemetry, but obviously that is my next plan. I need to get the Telemetry reading app (forgive me I can never remember what it's called) installed on this new Win 10 machine, but will try that tomorrow. Am I right in thinking I have to run that in Win 7 compatibility mode, but that if I do so and use the Yuneec USB cable specifically, I am expecting that to work right ?
So anyway, there is my initial account before I forget it ! More to follow as investigations continue...
AJ
EDITED in light of new evidence so report remains accurate.
Last edited:
just trying to find the original yuneec cable now... will upload logs when I have them.
