# Disarm bug according to landing speed

**URL:** <https://discuss.px4.io/t/disarm-bug-according-to-landing-speed/27573>\
**Category:** PX4 Autopilot\
**Created:** [May 22, 2022, 2:47pm UTC](https://discuss.px4.io/t/disarm-bug-according-to-landing-speed/27573 "2022-05-22T14:47:38Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![JAEPIL\_YOO](https://discuss.px4.io/user_avatar/discuss.px4.io/jaepil_yoo/32/5794_2.png) [@JAEPIL\_YOO](https://discuss.px4.io/u/JAEPIL_YOO)\
**Post date:** [May 22, 2022, 2:47pm UTC](https://discuss.px4.io/t/disarm-bug-according-to-landing-speed/27573/1 "2022-05-22T14:47:38Z")

</div>

Hi.

I recently conducted “precision landing test” using irlock several times, and found out that the accuracy increases according to the landing speed (mpc\_land\_speed).

I conducted a vicious test where the copter was smashed even if it was 5cm away

Starting with 0.7 m/s, the landing speed (mpc\_land\_speed) has been reduced to 0.2 m/s.  
(0.2 m/s is forced to store parameters)

(0.7/0.6/0.5/0.4/0.3/0.2 were performed 100 times each, and the lower the speed, the better the accuracy)

At 0.2 m/s, the success rate within 5cm was shown through the irlock in approximately 700 landing tests without a single error, but there was a problem.

In the manual position mode, it was a problem that even if the cop touches the ground, the disarm did not work.

Does anyone know about this problem?

I wonder why the minimum landing speed is 0.6m/s in px4.