MAV_CMD_DO_CHANGE_SPEED isn't work in vtol plane when its vtol state is MAV_VTOL_STATE_FW

ArduPlane VTOL Plane
,
1

Dear all,

I want to control a vtol plane to folloing a moving target.

First, I use MAV_CMD_DO_VTOL_TRANSITION
to change MAV_VTOL_STATE_FW to MAV_VTOL_STATE_MC.

Second, I want control speed of vtol plane, but it is not work by using MAV_CMD_DO_CHANGE_SPEED. Its speed still is fixed value.
Is there others method to control speed in vtol mode?

Many thanks.

I-Chia