# Switch to offboard/automission mode does not work

**URL:** <https://discuss.px4.io/t/switch-to-offboard-automission-mode-does-not-work/38643>\
**Category:** PX4 Autopilot\
**Created:** [May 9, 2024, 7:55am UTC](https://discuss.px4.io/t/switch-to-offboard-automission-mode-does-not-work/38643 "2024-05-09T07:55:13Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![phaas](https://discuss.px4.io/letter_avatar_proxy/v4/letter/p/ecae2f/32.png) [@phaas](https://discuss.px4.io/u/phaas)\
**Post date:** [May 9, 2024, 7:55am UTC](https://discuss.px4.io/t/switch-to-offboard-automission-mode-does-not-work/38643/1 "2024-05-09T07:55:13Z")

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Hi there,

I am writing since I implemented all my stuff and thoroughly tested it in SITL with the PX4 firmware in Gazebo using ROS noetic. I checked the serial connection established when running `roslaunch mavros px4.launch fcu_url:=/dev/ttyACM0:921600` which shows a healthy state. However, when I am then starting the Python offboard example provided here: [MAVROS Offboard control example (Python) | PX4 Guide (main)](https://docs.px4.io/main/en/ros/mavros_offboard_python.html), I cannot really arm the drone and switch into offboard mode. My observations on QGC are that the FCU has no GPS lock for Vehicle. However, I changed the param [COM\_ARM\_WO\_GPS](https://dev.px4.io/master/en/advanced/parameter_reference.html#COM_ARM_WO_GPS) according to this post here: [No GPS Lock for Vehicle](https://discuss.px4.io/t/no-gps-lock-for-vehicle/19446). I am pretty new to this stuff and maybe I am missing a configuration of one parameter or so. I also uploaded my flight logs here: [https://review.px4.io/plot\_app?log=b4660b85-99f5-4873-aa1c-257ff5fda95a](https://review.px4.io/plot_app?log=b4660b85-99f5-4873-aa1c-257ff5fda95a)

Thanks a lot.