The average plane is a massive machine that weighs several tons and generates millions of dollars for an airline over its life by transporting countless passengers and thousands of pounds of cargo several times a day. This volume and intensity are why planes need to be maintained often and why HPUs are often seen at the center of these maintenance attempts because of their various effects on a plane.
- Function
Hydraulic fluid is a core component of nearly every machine in the world because it allows pressure to be uniformly transferred, which engineers have been able to harness to ensure people can control huge pieces of equipment ranging from cranes to cars and other vehicles effectively. This is no different in aircraft, as the hydraulic power unit provides the pressurized fluid in planes that is necessary to ensure pilots can always make small adjustments to vital parts of the plane, like the wings and, most importantly, the landing gear. The entire process of landing on the runway is controlled using systems that are powered by hydraulic fluid, from incredibly powerful brakes to the wheels that have to take a load of thousands of pounds of weight from the plane’s body and its passengers.
- Components
The components of an average HPU are intricately designed to ensure that the fluid entering the plane is in as good a condition as possible since hydraulic fluid can degrade, too, and its degradation can have severe implications on the safety of an average flight, especially its landing. The central hydraulic pump pumps all of the fluid that a plane needs with enough speed that planes can be topped up easily without needing a lot of downtime, and their suction capabilities can remove the worn-down fluid present in the plane, which is why these units are such a crucial part of regular maintenance.
- Types of hydraulic systems
There are many different systems in planes, all of which are separated from each other so that they can be controlled independently. If there’s an issue in any one system, it’s localized and doesn’t spread anywhere else. This philosophy extends to hydraulic fluid, too, since the two most important systems are primary flight control systems, which handle everything from the rudders on the wings to control the angle of a flight to ailerons and everything else that’s used to make minor changes mid-flight, and secondary systems, which are the ones that encompass landing gear, brakes, and flaps.
- Maintaining HPUs
As previously mentioned, hydraulic fluid is integral to the core stability of any plane, and the HPUs that pressurize and power this fluid need to be kept in top shape to ensure the fluid that goes in is suitable. HPUs have a filter that removes tiny particles present in the hydraulic fluid, ensuring that it’s as consistent as possible, which will then ensure that pressure remains completely even. Still, these filters eventually get worn down and must be replaced. This ensures that HPUs don’t have to be replaced entirely and that one unit can be used for years, if not decades, delivering high-quality fluid for every flight in the long term.
- Recent advancements
Since planes are constantly being developed and made even more efficient, every other part of the maintenance chain has to follow suit, especially HPUs. Modern planes have newer fly-by-wire systems that allow pilots even greater control of their planes, even if it’s not directly and mechanically linked. Hydraulic fluid remains at the core of this system, too, which means that the hydraulic fluid in these planes needs to be better maintained than ever. Newer units are more lightweight and even more durable, which means that most airports and planes in the world can include high-quality pressurized fluid in all of their systems.
Conclusion
Hydraulic fluid is a necessity in most modern machines, but even more so in planes that cannot be controlled or manipulated through conventional means. The hydraulic systems present in every modern plane allow for many things, including for the landing gear to open or retract on command, as well as moving the wings of the plane during a flight that allows the pilots to change the direction they’re going in.