777 Autothrottle wake up
With the autothrottle armed, the autothrottle automatically activates if no autopilot or F/D is active or an autopilot or F/D is in VNAV XXX, ALT, V/S, or G/S, and:
• speed less than an FMC calculated value for one second
• thrust below reference thrust
• airplane altitude above 100 feet RA on approach, or airplane barometric altitude 400 feet above airport on takeoff
The autothrottle can support stall protection when armed and not activated. If speed decreases to near stick shaker activation, the autothrottle automatically activates in the appropriate mode (SPD or THR REF) and advances thrust to maintain minimum maneuvering speed (approximately the top of the amber band) or the speed set in the mode control speed window, whichever is greater. The EICAS message AIRSPEED LOW displays.
Note: When the pitch mode is FLCH or TOGA, or the airplane is below 400 feet above the airport on takeoff, or below 100 feet radio altitude on approach, the autothrottle will not automatically activate.
Note: During a descent in VNAV SPD, the autothrottle may activate in HOLD mode and will not support stall protection.