Yet another flyway in the north

[DoomMeister]

I am a little confused at this point. Is the GPS drawn from the sensor file or from the telemetry file? It's not clear to me what kind of information the sensor files contain and how it can be displayed in the software. When opening the sensor file, I see a table of what looks like hexadecimal numbers.

In general, are you surprised that the 2.4GHz link was cut so quickly?

There is a setting in Q500log2kml to create a kml file from the Sensor file. It will be named with the same number and have the kml extension.
When you use the Convert button on the upper right of the program window it converts the Telemetry data to kml format. Both can be viewed in Google Earth and compared.
The camera link is 5.8 GHz WiFi and the control and telemetry link is 2.4 GHz radio. I was concerned at the short distance that the link appeared to be severed. 250 meters is not that far.

 

[ukaleq]

There is a setting in Q500log2kml to create a kml file from the Sensor file. It will be named with the same number and have the kml extension.
When you use the Convert button on the upper right of the program window it converts the Telemetry data to kml format. Both can be viewed in Google Earth and compared.
The camera link is 5.8 GHz WiFi and the control and telemetry link is 2.4 GHz radio. I was concerned at the short distance that the link appeared to be severed. 250 meters is not that far.

Really? I just checked the manual, it says
"The concept of sensor data for Typhoon H Plus has changed, format too. The file name numbers of sensor files cannot assigned to the other files in FlightLog. Thus, sensor data only can be opened and displayed as single file by menu item “Open Sensor file from YTH+...” in main menu. Due to missing documentation, no interpretation or analysis of those data sets is possible, except text messages which can be found in AppLog."

 

[AH-1G]

@ukaleq
do you have version 4.1?

 

[ukaleq]

No, 3.8
Good point!

 

[DoomMeister]

No, 3.8
Good point!

major differences between the two versions, Helmut has put a lot of work into the upgrades focusing on the PX4 flight controller in the H520, TH Plus, and Mantis Q. You must be running Windows 64 bit or Linux 64 bit to get the latest updates (too few using 32 bit machines to warrant the time spent updating).

 

[ukaleq]

Thanks, I installed it and I am able to see the gpx files drawn from the sensor data. But that record is indeed very incomplete.

 

[AH-1G]

Thanks, I installed it and I am able to see the gpx files drawn from the sensor data. But that record is indeed very incomplete.

That would be an @h-elsner feed back.
How do you mean incomplete, in what way?

 

[ukaleq]

That would be an @h-elsner feed back.
How do you mean incomplete, in what way?

I mean that there is data for only part of the flight.

 

[ukaleq]

Another thing I notice is that between 8:26:10 and 8:26:20, you still see some changes in the stick input for roll and pitch, yet the copter has already initiated its "escape" and it is hard to see any impact of those on the flight path. That corresponds to my memories of the scene, and based on the absence of reaction I decided to trigger the RTH.

 

[AH-1G]

I saw that, I think it was fighting for its life?
Are you planning going to top of the hill and find the drone?
I guess that's a ski slope?
If winds were 290° it should be there?

 

[AH-1G]

Were there any power lines close to you when flying or other obstacles?

 

[xspwhite]

I'm impressed. It sounds like he may have a good chance of finding it.

 

[h-elsner]

Another thing I notice is that between 8:26:10 and 8:26:20, you still see some changes in the stick input for roll and pitch, yet the copter has already initiated its "escape" and it is hard to see any impact of those on the flight path.

The bad things happen when the sticks are in neutral position (2048).

The path has not changed but the speed is following the stick movements. The roll and pitch angle is same as before and corrospondents with the sticks as before. This can be seen clearly in the two pictures from the critical last minute.
Please keep in mind you have had only 70-80% for mx/min stick position. The position of the slider cannot be seen because it will not be sent. It is only used to limit the values for min/max. Unfortunately this is not visible in HW monitor but you can check this in channel settings. +/-100% is rabbit, +/-60% is turtle mode.
This limitation is then indirect visible in the Remote_xxxxx.csv.

 

[Ty Pilot]

Other questions:

• what is the correspondence between the flight modes and the numbers displayed? Looking at previous flights I keep seeing frequent changes...
• is it possible to tell the position of the turtle/hare control?

Anyway, I think the software is really botched. If the copter, for some reason, switches to manual mode, there should be a message that says it clearly (also with a sound, we are supposed to fly LOS and not to be always looking at the screen). It should also alert you on the speed control setting because indeed if you were at the lowest possible setting when GPS was active (so as to maneuver the copter very accurately) that becomes a potential danger when the copter abruptly switches to manual.

I have not been following this thread too closely since many guys are already on it but: I went back and read through and one thought popped into my head when I read this.

IPS Mode. I have seen on a few occasions when I am close to, or surrounded by, trees - the message - 'GPS lost IPS Mode activated' or something to that effect. On the Plus, IPS Mode is activated automatically. So just a thought I would throw that into the mix - is it possible this is what happened? Or would IPS Mode be clearly indicated in the telemetry files? Perhaps @h-elsner knows?

 

[ukaleq]

The bad things happen when the sticks are in neutral position (2048).

That's correct: I was looking at the screen at this time and when I looked again I saw that the copter had started drifting.

The path has not changed but the speed is following the stick movements. The roll and pitch angle is same as before and corrospondents with the sticks as before. This can be seen clearly in the two pictures from the critical last minute.

Do the roll and pitch values come directly from the IMU? Indeed you see that the roll/pitch and corresponding stick inputs are correlated and then some correlation between the roll/pitch (as illustrated) and the tas. But even though the speed diminishes at some points (mainly between 26:11 and 26:13) it's not enough to stop the copter. However, just 30 seconds earlier roll/pitch values of similar amplitudes could maintain it at low speed.

If I am correct (?) that could only be explained by a sudden and very sharp acceleration of the wind, something I am frankly skeptical of. Could there be an issue with the IMU?

Regarding the possibility to recover it: I left Finland on the same afternoon it happened. If radio contact had been maintained until descent had started I could have asked someone to go there but in this case, the search area would be very large. Plus if it crashed/crash-landed in a tree covered area, it makes it even less likely to find it.

Which points would you emphasize in your communication with Yuneec?

 

[AH-1G]

That's correct: I was looking at the screen at this time and when I looked again I saw that the copter had started drifting.



Do the roll and pitch values come directly from the IMU? Indeed you see that the roll/pitch and corresponding stick inputs are correlated and then some correlation between the roll/pitch (as illustrated) and the tas. But even though the speed diminishes at some points (mainly between 26:11 and 26:13) it's not enough to stop the copter. However, just 30 seconds earlier roll/pitch values of similar amplitudes could maintain it at low speed.

If I am correct (?) that could only be explained by a sudden and very sharp acceleration of the wind, something I am frankly skeptical of. Could there be an issue with the IMU?

Regarding the possibility to recover it: I left Finland on the same afternoon it happened. If radio contact had been maintained until descent had started I could have asked someone to go there but in this case, the search area would be very large. Plus if it crashed/crash-landed in a tree covered area, it makes it even less likely to find it.

Which points would you emphasize in your communication with Yuneec?

Unfortunately that's an expensive toy to be left behind.
Is anyone in Finland near the crash site want to look for it?

 

[h-elsner]

Which points would you emphasize in your communication with Yuneec?

The main question to Yuneec here is, why GPS was lost although the GPS accuracy is good (~60cm vertical, ~30cm horizontal), GPS fix is most of the time '3D position' but also 'DGPS/SBAS aided 3D position' (all from sensor file). So, why switch to manual mode without flight mode switch touched?

br HE

 

[AH-1G]

The main question to Yuneec here is, why GPS was lost although the GPS accuracy is good (~60cm vertical, ~30cm horizontal), GPS fix is most of the time '3D position' but also 'DGPS/SBAS aided 3D position' (all from sensor file). So, why switch to manual mode without flight mode switch touched?

br HE

Just spoke with @Ty Pilot, he has an interesting observation that happened to him.

 

[ukaleq]

The main question to Yuneec here is, why GPS was lost although the GPS accuracy is good (~60cm vertical, ~30cm horizontal), GPS fix is most of the time '3D position' but also 'DGPS/SBAS aided 3D position' (all from sensor file). So, why switch to manual mode without flight mode switch touched?

br HE

Thanks, what do you think about my point regarding the speed of the aircraft and possible wind drift?

 

[AH-1G]

Thanks, what do you think about my point regarding the speed of the aircraft and possible wind drift?

@ukaleq
Did you happen to fly under any branches, I see lots of trees in your area.
I'm not saying it's your fault, we're trying to narrow this down.