Fall from sky? What happened!?!

[Toophless]

Please refer to this thread How To Get H Plus Telemetry Files and then post those files here. We are trying to see if there is a common cause to these loss of control situations. Be sure to include all four categories for the telemetry.

DoomMeister...my aircraft was a Typhoon q500 4K. It was about four years old with the old white controller

 

[oliver]

I experienced the same problem. However I had just taken off from a boat in the San Francisco Bay, took it up to about 200 feet and out about 100 feet when it came home on its own. I was not in "HOME" mode. about 5 feet from the bow the Typhoon decided to land. It hovered about 6 inches off the water, but out of reach. Then it dropped onto the surface and sank like a rock. The last thing I saw on the controller was that it had lost contact with all GPS satellites both on the controller and the aircraft. Total loss.

no warning of weak batteries?

 

[PatR]

Or recycle it properly at places like Home Depot

If fully discharged after soaking in hot water they are safe both electrically and environmentally for disposal in common garbage.

 

[Ty Pilot]

Keepin count here... is that 5 Plus' reported a catastrophic failure in the last 2-3 weeks?

Okay so; two of the crashes before this post were not a Plus and one was was not even a Typhoon. My count is still three (3) Plus's have been reported as failing in flight.

 

[DoomMeister]

Okay so; two of the crashes before this post were not a Plus and one was was not even a Typhoon. My count is still three (3) Plus's have been reported as failing in flight.

I believe the count sits at 5 right now. Here are the pilots affected so far

@DarienR1, @Merhlin, @toddinroch, @per.strandqvist, @Seerabike. DarienR1 is the OP in this thread and the rest are in the H+ Discussion area.

 

[Ty Pilot]

Ah, okay @DoomMeister thanks. I forgot about Seerabike and Merhlin, and did not count Per.strandqvist as that was EU but if it is hardware related maybe we should.

 

[DoomMeister]

Ah, okay @DoomMeister thanks. I forgot about Seerabike and Merhlin, and did not count Per.strandqvist as that was EU but if it is hardware related maybe we should.

We are not sure at this point with Per’s H+ as to the actual cause. It appears that it had the same power failure as the others, and the previous successful flight had several alerts show up in the sensor file. I’m hoping he has been able to contact Yuneec and report back soon.

 

[Ty Pilot]

Okay, not sure if you've seen, but regarding reading the telemetry files; older versions of the program (Q500log) do not have the ability to properly interpret the extra columns of info in the Plus's telemetry and are creating false readings. This is per @h-elsner as he has confirmed that all of the over temp warning that I and others were seeing are in fact not there at all. In addition after I took some time to re-read and work through the 'History Notes' on the ST-16s I found that warnings I thought were happening in flight, were not. So for the moment we still have some in flight failures but it is still not determined what is causing it.

 

[DoomMeister]

Okay, not sure if you've seen, but regarding reading the telemetry files; older versions of the program (Q500log) do not have the ability to properly interpret the extra columns of info in the Plus's telemetry and are creating false readings. This is per @h-elsner as he has confirmed that all of the over temp warning that I and others were seeing are in fact not there at all. In addition after I took some time to re-read and work through the 'History Notes' on the ST-16s I found that warnings I thought were happening in flight, were not. So for the moment we still have some in flight failures but it is still not determined what is causing it.

Yes, I saw his post on getting the proper error messages in his program.

The Sensor files will show the warnings that get displayed on the ST-16S screen, and can be manually looked at in a text editor or in ArduPilot Mission Planner.

Those messages may show in a history folder on the controller. That might be worth investigating.

 

[per.strandqvist]

We are not sure at this point with Per’s H+ as to the actual cause. It appears that it had the same power failure as the others, and the previous successful flight had several alerts show up in the sensor file. I’m hoping he has been able to contact Yuneec and report back soon.

Hi, I today handed my H+ over to Yuneec Service in Moscow. Met and talked to the service engineer. He had already seen all my info here on the forum, and downloaded the logs to check. His very preliminary diagnose was some kind of power failure, possibly INSIDE the battery, if I understood him correctly. He mentioned som electronics inside the battery, but I did not catch the details. The logs are sent to Yuneec Germany (Europe HQ I guess). They will come back with details and decision mid next week. The service engineer in Moscow will check the hardware. Either replacement (quick) or repair(some weeks to ship spares to Russia).

I will post after getting news from Germany.

Regards,

Per

 

[AH-1G]

Hi, I today handed my H+ over to Yuneec Service in Moscow. Met and talked to the service engineer. He had already seen all my info here on the forum, and downloaded the logs to check. His very preliminary diagnose was some kind of power failure, possibly INSIDE the battery, if I understood him correctly. He mentioned som electronics inside the battery, but I did not catch the details. The logs are sent to Yuneec Germany (Europe HQ I guess). They will come back with details and decision mid next week. The service engineer in Moscow will check the hardware. Either replacement (quick) or repair(some weeks to ship spares to Russia).

I will post after getting news from Germany.

Regards,

Per

Relay switch?
When the contacts are closed the contact resistance should be zero, a short circuit, but this is not always the case. All relay contacts have a certain amount of “contact resistance” when they are closed and this is called the “On-Resistance”, similar to FET’s.

With a new relay and contacts this ON-resistance will be very small, generally less than 0.2Ωbecause the tips are new and clean, but over time the tip resistance will increase.

For example. If the contacts are passing a load current of say 10A, then the voltage drop across the contacts using Ohms Law is 0.2 x 10 = 2 volts, which if the supply voltage is say 12 volts then the load voltage will be only 10 volts (12 – 2). As the contact tips begin to wear, and if they are not properly protected from high inductive or capacitive loads, they will start to show signs of arcing damage as the circuit current still wants to flow as the contacts begin to open when the relay coil is de-energized.
https://www.electronics-tutorials.ws/io/io_5.html

 

[h-elsner]

Q500 had two MOSFETs, Typhoon H four to switch the power by the small button. I think H Plus has also MOSFETs to do this. I do not believe, there is a relay in.

As far as I know, there is no electronics in the batteries. The only thing I can imagine is a thermo switch (as laptops have) but this would be a bad decision (better battery too hot than fell from sky).

br HE

 

[AH-1G]

Q500 had two MOSFETs, Typhoon H four to switch the power by the small button. I think H Plus has also MOSFETs to do this. I do not believe, there is a relay in.

As far as I know, there is no electronics in the batteries. The only thing I can imagine is a thermo switch (as laptops have) but this would be a bad decision (better battery too hot than fell from sky).

br HE

So could we assume, the MOS capacitor or the Oxide in the MOSFET could be the culprit? Or maybe a diode to protect the load?

 

[h-elsner]

Yes, that's possible but not very probable. Once the MOSFET burns down, you have a shortcut, means alway on (not off). And there ar four in parallel.

But I can only talk about Q500 (has two MDU3603 parallel) and Typhoon H which has four on the bottom side of the mainboard. I hope, I remember right but think those are TPCA8128, each can switch 30A.

br HE

 

[DoomMeister]

My understanding for multicell LiPo battery packs is that there are electronics that are at least used in the charging of the batteries. So a failure in that circuitry could possibly affect battery output.

It was good to hear that a Yuneec employee is actually reading our forum and staying abreast of developments in our community!!! Whomever you are, hats off to you!!!

 

[Ty Pilot]

Yeah that part kind stuck out to me too. Will be interesting to hear how all this unfolds.

 

[AH-1G]

My understanding for multicell LiPo battery packs is that there are electronics that are at least used in the charging of the batteries. So a failure in that circuitry could possibly affect battery output.

It was good to hear that a Yuneec employee is actually reading our forum and staying abreast of developments in our community!!! Whomever you are, hats off to you!!!

Hmmm, that would be interesting, in order to supply energy back to the batteries you'll have load from that source, so it can't be much current?
I can only think of the motors producing energy back into the system, but that would counter productive.
We designed and manufactured one of a kind generators for government agencies, among other things.
N42 and N45 round and rectangular

 

[AH-1G]

@h-elsner elsner
After reading about TPCA8128, I agree failure is not probable, 150°C in order to get damaged.
What type of application processor does the H use?

 

[AH-1G]

My understanding for multicell LiPo battery packs is that there are electronics that are at least used in the charging of the batteries.

@DoomMeister
Piezoelectricity, Pizoelectric?

 

[h-elsner]

All LiPo that I have destroyed up to now, there nothing in but wires.

On the upper side of the processor board is an ARM STM32F405.


On the bottom side, there is 'something' that I could not identify, maybe only cooler pad.


br HE