Full throttle after disarm

[btastic]

Describe the issue

Hi there, this is a cross post from the betaflight repo: betaflight/betaflight#14581

@haslinghuis asked me to also open an issue on this repository.

Describe the bug

After test flying my newly built quad, I tried to land next to me, as I have often done in the past. When I hit disarm, the quad lowered a bit and then started to go full throttle out of a sudden. The quad was not reacting to any inputs anymore (arm/disarm again, throttle, pitch, roll). Luckily it got stuck in a nearby bush then flipped upside down and buried itself in the dirt. I carefully approached it, stepped with one foot on it, and unplugged the battery. Never powered it on again after this. I ultimately decided to shelf the stack. This incident happened a few months ago, but I couldn't find anything related to it, and decided to not report it.

A pilot from our group had this happen today aswell. I can provide the exact details for him too, but I'd need to ask him for it. He also wanted to land, disarmed, quad hit the ground, then it went full throttle into a nearby rock, and luckily that crash disconnected the battery. Since this happened now twice within a few months, I decided to report it here for further investigation.

I still have the electronics around if some testing is needed.

I know about ELRS and channel 5/AUX1 and this is configured accordingly.

To Reproduce

Not sure how to reproduce, and to be honest, I don't want to experience it again.

Expected behavior

Disarm should disarm the quad.

Support ID

e622b491-c43c-4354-81fd-2fb467d604e8

CLI dump from the second pilot:
BTFL_cli_20250813_115055_SPEEDYBEEF405V3.txt

Flight controller

GOKU F722 PRO V2 50A BLS (MPU6000)

Other components

ESC: GOKU 506S 50A BLheli_S 2-6S ESC, which I have flashed Bluejay v0.21.0 on.

RX: Radiomaster RP1 Receiver (ELRS Version 3.5.3)

VTX: Caddx Vista

How are the different components wired up (including port information)

ELRS on UART2 (soldered, not plugged)
Vista on UART3 (soldered, not plugged)
Beeper on the beeper pads

Add any other context about the problem that you think might be relevant here

The OSD was flickering for me in my flight, which made me decide to land. The other pilot did not have any flickering, so maybe unrelated, maybe not.

DVR footage is here:
https://github.com/user-attachments/assets/51149523-2697-43c7-830d-608e4896456e

DVR footage from the other pilot:
https://github.com/user-attachments/assets/edd806b1-165f-432a-9d94-dcda99b5b951

No blackbox data, unfortunately.

Bluejay version

0.21.0

ESC variant

J-H-15

PWM frequency

24

DShot bitrate

600

Bidirectional DShot

On

FC firmware

Betaflight 4.5

Motor size

2207

Configurator debug log

No response

[stylesuxx]

Please also share your exact ESC settings and BF config dump.

I can understand that you don't want to reproduce, but still, I am afraid that without attempting it, there is little we can do here. It would be really interesting if you could try to reproduce the issue without props on. Also from what I can see, this FC does have a Blackbox - so please enable that too for any further testing.

Also please share the specs of the other pilot.

[btastic]

Here is a screenshot of the ESC Configurator with the ESC in question:

And here is the CLI dump:
BTFL_cli_20250813_100657_FLYWOOF722PRO.txt

I have already said in the betaflight issue, that this error happened twice in ~6 months, with hundreds, if not thousands of disarms/arms. So my testing would basically be "arm, disarm" for hours. I would love to automate that somehow.

Would be building a circuit that could arm/disarm the drone repeatedly, and then checking each motor pad for signals be a feasible thing to do? I have no idea how to do any of that, there is also a lot of current and voltage at play, so this is probably not something that is easy to do. But I am trying to find a way for me to actually test this in a reasonable matter. I can't sit here for hours arming and disarming in the hopes that it occurs once.

[btastic]

I just heard back from the second pilot, here are his ESC settings:

And here is his CLI dump:
BTFL_cli_20250813_115055_SPEEDYBEEF405V3.txt

He was using a SpeedyBee F405 V3 with a SpeedyBee BLS 50A ESC. RX is ELRS with a RP1