What must you do to return the AC ESS BUS and ACMP 3B pump to normal aircraft power once the ADG deploys?

• A. Reset the aircraft's power with the battery switch
• B. Start the APU to restore power
• C. Connect External Power to the aircraft
• D. Press the PWR OVERRIDE button on the ADG control panel

Answer: (D)

When the ADG (air-driven generator) deploys, it automatically powers the essential electrical bus and related equipment to keep critical systems alive, but it leaves the normal generators and distribution from the primary sources isolated. To return to normal aircraft power, you use the PWR OVERRIDE control on the ADG panel. Pressing this button reconfigures the electrical system so that the AC essential bus and the ACMP 3B hydraulic pump are restored to normal power sources (APU or external power and the engine-driven generators) as soon as those sources are available. In short, the override instructs the system to switch back from emergency ADG power to the standard power distribution.