Can't take off in HITL and PX4 1.9.2


Currently I’m working on a drone project with a compagnon board and a Pixhawk 2 autopilot with firmware PX4 1.9.2.

Our compagnon code is based on the code from this example: and it work well on HITL with JmavSim simulation and PX4 version 1.6.5 to 1.8.2 but the simulated drone won’t take off with PX4 version 1.9.2.
With PX4 1.9.2, the simulated drone could be armed and set into offboard mode but that’s all.

Take off request is sent to the autopilot with the mavlink message SET_POSITION_TARGET_LOCAL_NED and a specific bitmask (see This request work with PX4 version 1.8.2.

Does anybody knows why the take off isn’t working between these two versions or the mavlink messages sequences to operate a take off ?

Thank you for your help and advices