What happened:
Start of my TREX 550 with Spirit GTR and Geolink V1.
Automatic rescue enabled at about 5m altitude.
Test whether automatic rescue works: o.k.
Then at a height of about 17m suddenly collective pitch can no longer be controlled. Heli descends slowly to the ground at constant speed, unfortunately into a field of sunflowers.
Investigation afterwards:
Battery was still plugged in. All functions (cyclic, tail) worked normally, only collective pitch did not and was in a constant position. Switching the rescue function off and on did not change anything.
Disconnecting the battery and switching it on again: everything is OK, collective pitch is also working again.
BEC test: During the Spirit BEC test, the BEC voltage fluctuates between 5.9V and 5.5V. This is also the voltage range from previous flights.
Configuration: Jeti DC24, TREX 550 with Hobbywing Platinum V4 and safety caps, 4700uF low ESR cap from Hobbywing. Current firmware in GTR 4.7.0 and GEOLINK.
Unfortunately, I have only the Jeti log file, but Spirit logging was not enabled.
What can I do to avoid such situations?
Konrad

Hello,

I am sorry to read about the crash.

From your settings and description, technically this condition could happen if:
1) Rescue (Normal) or Rescue (Automatic) or Return to Home will remain active - all these 3 are assigned and could be engaged.
2) Return to Home engaging switch was by mistake left at Programming State. Normally programming is not possible when flying, but in certain condition it could trigger programming of new Home position while in flight if switch is engaged all the time. Or possibly it was still in the programming mode even before lift off.
When engaging Rescue it has bigger priority, for this reason a Rescue will react even if RTH was engaged in any mode.

I can't see any other explanation, because only in condition that these features are engaged collective pitch can't be controlled.

Unfortunately log does not contain switch position, only sticks are visible.

I hope this can be helpful.

_________________
Spirit System developer

All switches are connected to a voice message so that I can rule out the possibility of accidental activation. The DC24 is programmed such that RTH position can be set only when motor is off. RTH was definitely not activated.
It was the second flight of the day. The first flight was okay. After the crash, my colleagues and I checked everything carefully. No switch was in the wrong position.

It looked as if automatic landing had been activated, although my configuration does not allow this.

The day before, I suddenly had the warning “Satellites 0” during a flight. I normally have 12 to 16 satellites. After landing and switching battery off and on again, several flights were possible without an error message. The cable is short an not near a motor or sevo and also the connectors are o.k.

I no longer have any confidence in this Spirit Unit. Can I send it to you in for testing? Or exchange it for a new one at extra cost?

Konrad

I have analyzed the flight from the previous Sunday: Strange behavior: Error message Satellite=0, but GPS data continues to arrive and is plausible, however altitude information is frozen. This is a flight with the TREX 550, which had a crash the following day. As already described, it looked as if Auto Landing had suddenly become active. Pitch no longer controllable and slow descent, unfortunately in a field of sunflowers. I have no switch to activate auto landing. This feature is disabled.

Hello,

you can send the unit to us. But please send also GeoLink as there is much bigger chance the problem is there. If both are under warranty then both can be replaced if no issue will be found.

https://spirit-system.com/repair.php

_________________
Spirit System developer