Balsa glider total crash nose down log, what happened?

So I crashed with APM 2.6 Ardu plane firmware after many settings and complications finally flew 15 minutes without problems and then the plane just went straight down like it was controlled, I had no response from radio I tried changing modes and no response from modes or any stick input. I don’t really understand what happened and was hoping to see in log but the log analyzer gives an error and cannot read my log, manually if I look on it I don’t understand much, maybe some of you can take a look and tell me what went wrong I appreciate. .log .bin

Anyone on this forum ?

A couple initial questions:
Your post suggests you’re using APM 2.6, but the log has a message indicating that you’re using Arduplane v3.4.0. Note that the documentation suggests Arduplane v3.3.0 was the last compatible firmware version:

Is there some mistake, or did you fly the APM 2.6 on an unsupported version of the firmware?

I didn’t change anything I just choose ardu plane and set up my plane. Who reads all this pages before even plugging in ? Is absurd…the software automatically updates, I remember a message who said my board is ended and last firmware supported is some numbers and I cannot update more so so I assume it automatically chooses the right firmware for my APM no ? this gets so complicated…I regret choosing APM

I do not have experience analyzing logs from ArduPlane v3.4.0. There are major anomalies in this log which look like bugs, and prevent me from understanding it. (undefined message formats are used, the timestamps don’t make sense, it looks like the log began while the plane was flying, etc.)

A few noteworthy things:

  1. Multiple (about 6) times during the flight, the battery voltage dropped from ~11v to ~9.75v. This triggered a low-voltage warning near where the pitch seems to go wild.
  2. The FailSafes were repeatedly triggered near the end of the log. I can’t tell if that’s after the crash, or part of the original cause.
  3. Some important log data appears not to have been recorded? (e.g. Barometer data is empty)

Anyways, if you flew with hardware which is many years old, and you had an incompatible firmware version, it might be impossible to find the true cause.

If you got a warning suggesting that your firmware might be unsupported, and you ignored it, that’s your fault… sorry.

If you read the warning, and verified that you were being led to upload a SUPPORTED version, but the message was wrong (and in fact the version was not supported) you’ve got a valid complaint. If you can document that, it would be a good service to the community.

Finally I especially represent ONLY my own opinion with this controversial statement: Autopilots are complicated. If you don’t want to deal with their complicated issues, don’t use them. It makes you a safety risk to yourself and to others.

I think the fail safe is after the crash when I turned off the radio.
I remember a notice window saying my board is old and it will be updated to the last supported firmware( or at least this is what I understood from it) I will try to reinstall the firmware and get the message again so I can screen shot it to be sure and maybe help in future if you think is some bug.

Also the voltage drop is when I was full throttle or accelerating taking the glider up in sky and then I stop motor and just glide

Your log has a lot of errors and some important datas are missing , so it is really hard to help you.

Looks like you loose several time your radio .