LAND mode put quad into the sea...

I had an unfortunate incident this afternoon which has cost me all my copter electrics including my Panasonic HDC TM700 camera. I had been through four battery packs without incident when suddenly my 2.9.1b quad started loosing altitude, ending up in the harbour fully submerged. The entire flight (or so I thought!) was in STABILIZE mode. Suddenly the quad stopped responding to my commands and started loosing altitude. I was not especially high in the first place and did not have enough wits about me to attempt to change mode. The quad simply descended into the sea some 50m away from me... I have telemetry via my 9x/Frsky and had no warning signs. Voltage, RSSI, GPS were all just fine. I have a failsafe set on the throttle that should engage RTL but have never used or configured LAND mode. After retrieving the rig and drying out the APM I downloaded the log only to find the LAND mode had been engaged!

From the log starting at line 8659:

EV: 15
EV: 30
ERR, FS, 3

I do not have LAND configured as any of the modes available via Ch5 switching.  Is there anyone who can shed some light on why this may have happened? What is EV 15 & 30? What is ERR, FS 3? If I am going to rebuild then I would really like to avoid this in the future...

2013-06-06 19-05 8.log

2013-06-06 19-05 8.kmz

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • man that's my worst nightmare I hope someone here will shed some insight for you.

  • After doing some more searching I have come up with some more info:

    EV: 15 -> #define DATA_AUTO_ARMED 15

    EV: 30 -> #define DATA_DESCENDING 30

    FS, 3 -> 3 = (from post by Randy here) Battery failsafe (voltage fell below LOW_VOLT parameter or total current of battery used -- sorry, i forget the parameter that holds that the mAh of the battery)

    I do not recall having ever set the battery failsafe however looking at my parameters from the log, FS_BATT_ENABLE is set to a value of 102. According the the Advanced Parameter List in the MP, valid entries for this parameter appear to be 0 or 1 so I am not sure how this came about but it may be the cause of my problem. LOW_VOLT is set at 9.6 and the lowest recorded voltage in the log is 15.22V so the FS must have been triggered by the total current used. This is entirely possible as I have recently installed current sensors but have not calibrated them yet. The system estimates current as being way too high but I did not see the harm in this believing that the FS was disabled. Just out of interest, I note that MAG_ENABLE is set to a value of 102 as well - this is also an invalid entry though  I have not had any indication that there was a problem with the magnetometers. I suspect that these values are handled in the code as a test for zero being the disabled and anything else taken as enabled. I have no idea how these entries have been corrupted

This reply was deleted.


Neville Rodrigues liked Neville Rodrigues's profile
Jun 30
Santiago Perez liked Santiago Perez's profile
Jun 21