The ground station went silent: the copter is acting on its own

What ArduPilot says:

• ERR FAILSAFE_GCS-1 (Subsys 8, ECode 1)

No heartbeat came from the ground station whose system ID is SYSID_MYGCS for FS_GCS_TIMEOUT seconds (5 by default), and the copter is doing what FS_GCS_ENABLE says: 1 RTL, 3 SmartRTL or RTL, 4 SmartRTL or Land, 5 Land, 6 mission landing or RTL, 7 Brake or Land; if RTL cannot start it lands. Stick commands the ground station was sending (a joystick) are dropped. If the transmitter's link is good, take over with the flight mode switch. While disarmed the line is only a notice.

What to do, most likely first

1. The telemetry radio went out of range; it usually reaches less far than the RC link.

   CheckThe ground station's link statistics drop before the event; the transmitter still controls the copter.

   FixRaise the ground antenna, keep line of sight, or plan the flight inside the telemetry's range.

2. The ground station program was closed, the computer went to sleep, or the cable was unplugged while the copter was armed.

   FixKeep the ground station running until the copter is disarmed; switch off the computer's sleep for the flight.

3. Telemetry travels over the RC link (ELRS or Crossfire MAVLink), so both were lost together.

   Check“Radio Failsafe” appears within a second or two of this line.

   FixTreat it as a radio failsafe: see “Radio Failsafe” for the causes.

4. The heartbeats come from another system ID than SYSID_MYGCS (a second ground station, a companion computer), so the real one is not counted.

   FixSet SYSID_MYGCS to the system ID your ground station uses (its own settings show it; 255 is the usual default).

The failsafe cannot trigger if no ground station was heard since power-on. With the default FS_OPTIONS (bit 4) it does not change mode while you fly by the sticks: the line then reads “GCS Failsafe - Continuing Pilot Control”.

Parameters to look at

Where to do it:Failsafe ExplainerSetup & Tuning GuideRadio Link Planner