# Terrain hold not holding

**URL:** <https://discuss.px4.io/t/terrain-hold-not-holding/14828>\
**Category:** PX4 Autopilot\
**Created:** [January 23, 2020, 12:05pm UTC](https://discuss.px4.io/t/terrain-hold-not-holding/14828 "2020-01-23T12:05:25Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![NicolasM](https://discuss.px4.io/user_avatar/discuss.px4.io/nicolasm/32/5240_2.png) [@NicolasM](https://discuss.px4.io/u/NicolasM)\
**Post date:** [January 23, 2020, 12:05pm UTC](https://discuss.px4.io/t/terrain-hold-not-holding/14828/1 "2020-01-23T12:05:25Z")

</div>

Hello,

I tried to used terrain hold with a lidar lightware LW20C but my drone drift (following baro baro). distance\_bottom estimation seems correct but the altitude set point is not updated.  
MPC\_ALT\_MODE is set to 2  
I use an hexacopter with px4 v1.10.1 on a cube.

here is a log: [Flight Review](https://review.px4.io/plot_app?log=4f3fa1ac-b06d-4d55-8f01-5e7ba7b1dbde)

A mounth ago, I tried it with v1.9.2 and it was fine.

What can block terrain hold to be activated ?