# Another crash EKF2 latest stable. Disarmed mid flight **URL:** \ **Category:** PX4 Autopilot\ **Created:** [May 23, 2016, 5:23pm UTC](https://discuss.px4.io/t/another-crash-ekf2-latest-stable-disarmed-mid-flight/459 "2016-05-23T17:23:03Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![Ilia\_Sheremet](https://discuss.px4.io/user_avatar/discuss.px4.io/ilia_sheremet/32/230_2.png) [@Ilia\_Sheremet](https://discuss.px4.io/u/Ilia_Sheremet)\ **Post date:** [May 23, 2016, 5:23pm UTC](https://discuss.px4.io/t/another-crash-ekf2-latest-stable-disarmed-mid-flight/459/1 "2016-05-23T17:23:03Z")
Just had another crash today with Latest stable EKF2. From the log messages I can see that it had disarmed itself during the flight, after it detected the land. So when it stopped logging, the copter started to fell down. I didn’t find anything from the log that could disarmed it like that, but I might take a deeper look, likewise check the source code for disarm logic. Some details about flight/takeoff: There was a try to arm when _safety-switch_=off, then we turned it on and arm copter, takeoff. In the beginning of flight we made a slight changes in attitude PIDs and it was flight afterwards without any issues for another 5 min. We also carelessly changed **MPC\_Z\_VEL\_MAX\_DN** parameter, even thought it was written not to change it in QGC parameter’s comment - we noticed it after the crash. **Frame:** Copter X4 **Firmware:** d017514d59a0c1b7467c89c45ebe106080fad102, Latest stable EKF2 **Conditions:** Almost no wind **UAVenture log:** [http://logs.uaventure.com/view/oJXaCcMLqEGdbWoexy8Y5A](http://logs.uaventure.com/view/oJXaCcMLqEGdbWoexy8Y5A) **Link to px4log, QGC log, other files on SDcard:** [https://drive.google.com/folderview?id=0B4HSR\_JQFK8KSnVNSDJISE1uNk0&usp=sharing](https://drive.google.com/folderview?id=0B4HSR_JQFK8KSnVNSDJISE1uNk0&usp=sharing) Would appreciate any help on that, thank you in advance!