Which hydraulic system provides parking brake operation?

Which hydraulic system provides parking brake operation?

• A. Blue
• B. Green
• C. Yellow
• D. Orange

Answer: (C)

The parking brake on an A320 is powered by the Yellow hydraulic system. This system has the dedicated parking brake valve and an accumulator that stores hydraulic pressure. When you set the parking brake, the valve traps pressure in the brake lines, holding the main wheel brakes applied even if other pumps lose power. Releasing the parking brake opens the valve and allows pressure to bleed off so the brakes release. This separation gives the parking brake its reliability, independent of the Green and Blue systems, which handle other hydraulic functions and normal braking during flight and taxi. The Yellow system’s role is specifically to provide and hold that parking brake capability.

The parking brake on an A320 is powered by the Yellow hydraulic system. This system has the dedicated parking brake valve and an accumulator that stores hydraulic pressure. When you set the parking brake, the valve traps pressure in the brake lines, holding the main wheel brakes applied even if other pumps lose power. Releasing the parking brake opens the valve and allows pressure to bleed off so the brakes release.

This separation gives the parking brake its reliability, independent of the Green and Blue systems, which handle other hydraulic functions and normal braking during flight and taxi. The Yellow system’s role is specifically to provide and hold that parking brake capability.