APM 2.7 with V3.1.2 - Fall out of sky while in Alti Mode

HI All.
I just need confirmation as to the plausible reasons for this failure.
Hope someone can help me analyze the attached logs.

QUick run down - i took off in Stabalize mode, switched to Alti Mode, and after a slight increase in altitude while in Alti Mode, it fell and rolled a few times.

You help will be greatly appreciated.

I ran your log on the APM Analyzer and:

  • RTL switch was down ( I don’t know your setup, but on my radio that would trigger RTL)

If you enable IMU there will be vibration information available.

I ran your log on the MP auto analyzer and:

  • Pitch/Roll test failed
    -GPS had a high HDOP (+3) ( I know AltHold doesn’t need it, just an FYI)
    ( If RTL triggered this would be an issue)

I don’t analyze the logs well manually, so please take what I found with a, “grain of salt.”

Perhaps one of the gurus will chime in.



Unfortunately you don’t have many logs enabled so its hard to say.

looks like it tips right and backwards so maybe you lost the rear right motor for some reason.

Do all of your motors work still?

THanks for the input guys!!!
I have a feeling that i had a prop break! not sure though. :frowning:

Yeah, all of the motors still work fine!
Im gonna put on another set of props and do ground testing.

SO - I finally got my quad off the ground again…and Ive had a few low to ground test flights.
Today i decided to recheck all for vibrations etc, test Alti Hold and Loiter.
Alti hold definitely needs some tuning - all bouncy…But I then wanted to just fly normally without any modes and before i go much higher - the quad decided to ROLL and fall!

PLEASE can someone help me look at the logs.
I wont be lifting this anytime soon until i find the EXACT reason!

I was under the impression that my first fall was as a result of a failed prop…but this time - all props were fine!

I did notice in the logs that the HDOP drops from 2.5 to 1.5 a few seconds before the roll and fall. Could it be linked?

Hope someone has the time to assist.
Cheers for now.