Hydraulic Failure and Alternative Hydraulic Systems

Introduction

Aircraft rely heavily on hydraulics to power vital systems like landing gear, brakes, flaps, and flight controls. A hydraulic system failure can pose serious risks to aircraft safety. However, aircraft are designed with redundancy to handle such failures effectively. Understanding this is a crucial part of DGCA Ground Classes for commercial pilot trainees.

1. The Role of Hydraulic Systems in Aircraft

Hydraulic systems use pressurized fluid to move mechanical components. In modern aircraft, they power:

• Primary flight controls

• Spoilers and flaps

• Landing gear retraction/extension

• Braking systems

• Thrust reversers

Each function requires high pressure (usually around 3000 psi) for smooth and responsive operation. These topics are thoroughly explained in DGCA Ground Classes using schematics and aircraft system diagrams.

2. What Happens During a Hydraulic Failure?

Hydraulic failure can be partial or complete and may occur due to:

• Fluid leakage

• Pump malfunction

• Contamination in the fluid

• Overheating of components

Symptoms include loss of control surface movement, landing gear retraction issues, or increased control forces. In DGCA Ground Classes, students study real-world examples of how pilots handled hydraulic failures under pressure.

3. Backup and Alternate Hydraulic Systems

To ensure safety, aircraft are equipped with multiple independent hydraulic systems (usually 2–3):

• Manual reversion systems

• Electric or air-driven pumps

• PTUs (Power Transfer Units)

• Ram Air Turbine (RAT) for emergency hydraulic power

These backup systems automatically or manually activate during primary system failures. DGCA Ground Classes teach the activation procedures and the limitations of each backup option.

4. Pilot Response and Emergency Procedures

In the event of a failure, pilots follow strict checklists which include:

• Isolating the faulty system

• Activating alternate pumps or systems

• Preparing for alternate gear extension

• Declaring an emergency and planning for a long final approach

Simulator sessions in DGCA Ground Classes help future pilots gain muscle memory for these steps in a calm and controlled manner.

Conclusion

Hydraulic failures are rare, but when they occur, the right knowledge and actions make all the difference. Aircraft systems are built with multiple layers of redundancy to keep flights safe.

To gain a deep understanding of hydraulic systems and emergency handling, join expert-led DGCA Ground Classes and train like a true professional.