Which hydraulic systems are cross-pressurized by the PTU?

Which hydraulic systems are cross-pressurized by the PTU?

• A. Yellow and Green
• B. Green and Blue
• C. Yellow and Blue
• D. Red and Yellow

Answer: (A)

The PTU is designed to cross-pressurize the Green and Yellow hydraulic systems to keep the primary flight-control actuators powered if one system loses pressure. On the A320, the primary flight controls are driven mainly by Green and Yellow hydraulics, so the PTU automatically connects pressure between these two circuits to maintain adequate force and motion for control surfaces. The Blue system operates independently and is not cross-pressurized by the PTU, and there isn’t a Red hydraulic system on this aircraft. So cross-pressurization by the PTU occurs between Yellow and Green.

The PTU is designed to cross-pressurize the Green and Yellow hydraulic systems to keep the primary flight-control actuators powered if one system loses pressure. On the A320, the primary flight controls are driven mainly by Green and Yellow hydraulics, so the PTU automatically connects pressure between these two circuits to maintain adequate force and motion for control surfaces. The Blue system operates independently and is not cross-pressurized by the PTU, and there isn’t a Red hydraulic system on this aircraft. So cross-pressurization by the PTU occurs between Yellow and Green.