STBY Mode (Momentary Action) Pushing the STBY pushbutton has the following effects on the AFCS:
• No effect on AP/YD engagement
• Clears all active and armed lateral and vertical FD modes and removes FD command bars if the AP is not engaged
• Clears all active and armed lateral and vertical FD modes and FD command bars remain if the AP is engaged (Flight Director FDreverts to basic mode)
• Clears FD abnormal messages