# Toiletbowling during takeoff after MAV\_CMD\_NAV\_TAKEOFF

**URL:** <https://discuss.px4.io/t/toiletbowling-during-takeoff-after-mav-cmd-nav-takeoff/49126>\
**Category:** PX4 Autopilot\
**Created:** [June 18, 2026, 2:16pm UTC](https://discuss.px4.io/t/toiletbowling-during-takeoff-after-mav-cmd-nav-takeoff/49126 "2026-06-18T14:16:19Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![blank-supportgis](https://discuss.px4.io/user_avatar/discuss.px4.io/blank-supportgis/32/10555_2.png) [@blank-supportgis](https://discuss.px4.io/u/blank-supportgis)\
**Post date:** [June 18, 2026, 2:16pm UTC](https://discuss.px4.io/t/toiletbowling-during-takeoff-after-mav-cmd-nav-takeoff/49126/1 "2026-06-18T14:16:19Z")

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I have a small octocopter running px4 1.17.0 on a pixhawk 6c. Lately, i have swapped the standard HG-C05 GNSS module for an Here4, so I can use RTK.

When I start it by hand in position mode, it usually starts fine, but when I autonomously start it with a MAV\_CMD\_NAV\_TAKEOFF from a companion computer, the start is really messy. Instead of flying straight upwards, it flies a toiletbowling-pattern and it’s yaw drifts up to 45°. When the takeoff height is reached, this scary presentation is usually over and the rest of the mission continues without issues.

I unfortunately don’t have a video, but the following graph outlines the problem:

 ![plot](https://discuss.px4.io/uploads/default/original/3X/2/8/286fe933bd4d32079f70b7439da563c8c6d55017.png)

It plots the position setpoints against the actual position, as well as the actual yaw. During takeoff (the blue z position line drops), you can see that the setpoints remain calm, but the actual positions are swinging around them by more than one meter. Also, the heading starts a sinusiodal oscillation, that quickly reduces. You can find the whole log under [https://review.px4.io/plot\_app?log=99a1a96f-36c1-48d2-8861-5decbbb87304](https://review.px4.io/plot_app?log=99a1a96f-36c1-48d2-8861-5decbbb87304)

So far, i tried setting EKF2\_MAG\_TYPE to 1 (recommendation from a certain AI) and giving it 10 seconds more waiting time after acquiring a home position and before arming.

Does anybody else have any more ideas?

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**Author:** ![system](https://discuss.px4.io/uploads/default/original/3X/7/3/73ce918bdcd64854de904f0c8d9ab70ca9723f2a.png) [@system](https://discuss.px4.io/u/system)\
**Post date:** [September 16, 2026, 2:16pm UTC](https://discuss.px4.io/t/toiletbowling-during-takeoff-after-mav-cmd-nav-takeoff/49126/2 "2026-09-16T14:16:56Z")

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