Air New Zealand Flight Experiences Mid-Air Hydraulic Failure

Earlier this week, an Air New Zealand flight from Christchurch made headlines after it was forced to perform an emergency landing at Sydney Airport due to a reported hydraulic system failure while flying over the Tasman Sea.

Passengers were informed mid-flight that the aircraft would be diverting, and the plane landed safely, where it was met by emergency crews and support vehicles.

No injuries were reported.

But the incident highlights the importance of hydraulic system reliability, especially in high-risk environments.

Hydraulics in Aviation — A Quick Overview

Hydraulics are fundamental to aviation. They provide the power behind landing gear extension and retraction, wing flaps and slats, wheel brakes, steering systems and cargo doors. In other words, almost every major mechanical operation on an airliner depends on stable hydraulic pressure. Aircraft engineers rely on hydraulics because they can generate high force from small control movements, all while remaining compact and highly responsive.

When something disrupts that pressure due to a leak, a pump malfunction or component fatigue, the aircraft’s control and handling characteristics can change. This is known as hydraulic failure or mid-air hydraulic failure if it occurs while the airplane is airborne.

What Happens When a Mid-Air Hydraulic Failure Occurs?

It's frightening to think about any disruptions happening while in the air. Nonetheless, there are numerous contingency plans to handle different types of disruptions. Commercial airplanes are not dependent on a single hydraulic circuit. They are equipped with multiple redundant systems so that if one fails, others can assume control.

During an in-air hydraulic failure:

1. The crew assesses which system is affected

2. Backup systems and emergency pumps engage

3. Aircraft handling characteristics may change

4. Pilots prioritise a controlled diversion and landing

   
   

This is why, even though passengers rightly felt concerned, the crew was able to land the aircraft safely.

Common Causes of Hydraulic Failure

Hydraulic systems are highly robust, but failures can occur due to:

Aircraft operate in extreme conditions like temperature swings, vibration and load cycling, which is why precision maintenance and fault monitoring are essential.

The Wider Lesson for All Industries

Hydraulic systems don’t only power airplanes. They drive agricultural machinery, industrial automation, lifting equipment, transport fleets, defence systems and more. You may already have seen these 7 Types of Trucks That Can’t Function Without Hydraulics while driving to work or around your neighbourhood.

And across all these sectors, the same principles apply:

• Component quality matters

• Correct fluid specification matters

• Seal and hose integrity matters

• Preventive maintenance matters

Failures rarely happen without early warning signs, but only if the system is designed to make those signs visible. Here are 7 Signs Your Hydraulic Hose Is About to Fail.

The Air New Zealand incident serves as a reminder that reliability is something that must be engineered deliberately. It comes from high-quality components, from system design that considers real-world environments, and from maintenance regimes that prevent problems long before they are noticed by an operator.

At Lister Fluid Power, this philosophy shapes the way we design and support hydraulic systems for OEMs. We focus not only on performance, but on long-term stability, serviceability and lifecycle assurance. When the system matters, whether in the air, on the road or on the factory floor, reliability cannot be an assumption. It must be built in.

If hydraulic reliability is critical to your operations, we’re here to help you strengthen it.