Flight Options

FLIGHT_OPTIONS is a bitmask that allows configuring several alterations to Plane’s behavior.

FLIGHT_OPTIONS	Function
0	Allows rudder input to be used in only MANUAL,STABILIZE,and ACRO modes. In other modes, rudder input mixing is controlled by the STICK_MIXING parameter.
1	Forces center throttle stick to be AIRSPEED_CRUISE instead of midway between AIRSPEED_MAX and AIRSPEED_MIN when using an airspeed sensor in FBWB and CRUISE modes.
2	Disable the attitude checks for AUTOTAKEOFF and TAKEOFF mode start which must be less than +/-30 degrees roll and 45 degrees pitch.
3	Forces target airspeed to AIRSPEED_CRUISE in CRUISE and FBWB modes when airspeed sensor is being used, ignoring throttle stick position.
4	Climb to RTL_ALTITUDE altitude before turning toward home in RTL
5	Enable Yaw Damping Controller to be active in ACRO mode
6	Suppress speed scaling during auto takeoffs to be 1 or less to prevent oscillations when not using an airspeed sensor.
7	Enable default airspeed EKF fusion for takeoff (Advanced users only)
8	Remove PTCH_TRIM_DEG offset on the GCS horizon to show pitch relative to AHRS trim (ie the attitude at which the autopilot was calibrated,unless manually changed)
9	Remove PTCH_TRIM_DEG on the OSD horizon to show pitch relative to AHRS trim (ie the attitude at which the autopilot was calibrated,unless manually changed)
10	Adjust mid-throttle to be TRIM_THROTTLE in non-auto throttle modes except MANUAL,instead of midway between MAX and MIN stick values (note that the RCx_TRIM value for the throttle channel (x) MUST BE set to center stick value)
11	Disable suppression of fixed wing rate gains in ground mode
12	Enable FBWB style loiter altitude control if STICK_MIXING is enabled
14	In AUTO, climb to next waypoint altitude immediately instead of linear climb

Default is no options enabled (“0”). Setting the bit will enable that function. For example, if forcing target airspeed in FBWB and CRUISE modes is desired, a value of “8” (bit 3 =1) would be set.

Note

Normally, PTCH_TRIM_DEG is subtracted from the AHRS pitch so that the artificial horizon shows pitch as if the autopilot was calibrated with aircraft level position set at PTCH_TRIM_DEG instead of flat. This normally results in the artificial horizon indicating 0 pitch when in cruise at desired cruise speed. PTCH_TRIM_DEG is the pitch trim that would be required in stabilized modes to maintain altitude at nominal cruise airspeed and throttle, and for most planes is 1-3 degrees positive, depending on the aircraft design (see Tuning Cruise Configuration).