Which indicator would illuminate if the Green or Yellow hydraulic reservoir is low?

Which indicator would illuminate if the Green or Yellow hydraulic reservoir is low?

• A. Amber FAULT on PTU pushbutton
• B. Red FAULT on EMER GEN
• C. Amber FAULT on IDG
• D. Blue ELEC Pump indicator

Answer: (A)

Understanding how hydraulic status is shown in the cockpit is key here. The Green and Yellow hydraulic systems feed the flight controls, and their quantities are monitored so the crew knows if a reservoir is getting low. The PTU (Power Transfer Unit) helps maintain hydraulic pressure if one system suffers a pressure drop. The pushbutton for the PTU has an amber FAULT light that will come on when the PTU cannot operate or when there’s a fault, which includes conditions where the hydraulic quantity in either the Green or Yellow reservoir is too low for reliable PTU operation. So, when a Green or Yellow reservoir level is low, the amber FAULT on the PTU pushbutton is the indicator that alerts you to degraded hydraulic support. The other indicators listed relate to electrical faults or generator/ pump status and do not indicate reservoir level, so they don’t serve as the signal for a low hydraulic reservoir.

Understanding how hydraulic status is shown in the cockpit is key here. The Green and Yellow hydraulic systems feed the flight controls, and their quantities are monitored so the crew knows if a reservoir is getting low. The PTU (Power Transfer Unit) helps maintain hydraulic pressure if one system suffers a pressure drop. The pushbutton for the PTU has an amber FAULT light that will come on when the PTU cannot operate or when there’s a fault, which includes conditions where the hydraulic quantity in either the Green or Yellow reservoir is too low for reliable PTU operation. So, when a Green or Yellow reservoir level is low, the amber FAULT on the PTU pushbutton is the indicator that alerts you to degraded hydraulic support. The other indicators listed relate to electrical faults or generator/ pump status and do not indicate reservoir level, so they don’t serve as the signal for a low hydraulic reservoir.