You Name It: Hydraulic Test Bench
For Cargolux, the 747 isn’t just an aircraft — it’s a trusted carrier perfectly suited to carrying oversized and heavy cargo around the world. As these iconic aircraft age and maintenance become more challenging, a dedicated team set out to build their own solution.
Through collaboration, determination and resourcefulness, they brought to life a brand-new hydraulic test bench, designed to keep the fleet flying strong.
WHAT: Understanding Hydraulic Systems
On a Boeing 747, the hydraulic system is important. "The 747 has four hydraulic systems for redundancy purposes," explains Frank, Senior Manager Production. "Hydraulic power moves the flight controls of the aircraft, operates the landing gear and assists in steering the aircraft on the ground." Adrian, Technician in the Hydraulic Pneumatic Shop, puts it like this: "Pressurized fluid makes things work. It has significant power, so it’s commonly used for heavy equipment like landing gears or brakes." Yet, like any system under stress, hydraulic components don’t last forever. Actuators, valves, and pumps wear down, leak, or lose precision — and every component must be tested before being approved for flight. "The manufacturer has clear specifications on how fast and how accurately actuators must perform," Frank notes. "And that’s exactly what a hydraulic test bench allows us to verify."
WHY: The Strategic Need for an In-House Test Bench
The idea for an in-house hydraulic test bench wasn’t born from convenience — it came from necessity. "The 747 was operated by many airlines for decades, but today, less and less remain," Frank explains. "Suppliers and repair shops have shifted focus to newer models like the Airbus A320 or Boeing 777. It becomes harder to find places willing — or able — to service 747 components."
The consequences were serious: repair times stretched to six weeks or more, including long shipping delays. "And the longer a component is away, the more spares you need to buy to compensate," says Frank. "That ties up a lot of resources."
Acquiring an in-house bench also meant regaining control over quality and timelines. "You decide what you repair" Frank adds. "You’re no longer depending on someone else's priorities or concerns of their profit margins."
Most importantly, it was about securing the future. "We want to continue operating the 747-400 until at least 2020s" Frank says. "Having this capability ensures we can support our fleet independently, even as external resources disappear."
HOW: Building the Project from Vision to Reality
Setting up a hydraulic test bench isn’t as simple as buying a machine — it requires careful planning and custom design. "You first define your needs: maximum pressure, maximum flow, and the types of components to test," Frank explains. "Then you select a manufacturer. In our case, we partnered with TestFuchs." The system was designed with modularity in mind — a philosophy the manufacturer actively promotes. It means Cargolux can adapt or upgrade the bench over time as operational needs evolve. In other words, the solution isn’t just for today’s requirements, but also for tomorrow’s needs.
The project progressed through a series of well-defined stages. It began with kick-off meetings to align on technical requirements, followed by detailed project design reviews to tailor the specifications to Cargolux’s needs. Shop Acceptance Tests (SAT) were then conducted at the vendor’s site, using actual Cargolux components to ensure compatibility and performance. The final phase involved installation and acceptance at Cargolux’s facilities, marking the successful completion of the project.
Adrian joined during the final stages and quickly immersed himself: "It was a very interesting project with many challenges, but we found solutions for every technical issue," he says. "Today, we are using the bench developed and programmed by TestFuchs, to follow the exact procedures required by each manufacturer."
Of course, no project goes entirely smoothly. "At one point, we discovered a test requirement that exceeded the bench’s original capacities," Frank recalls. "We had to develop a separate fixture to overcome that. It shows how important it is to stay deeply involved at every step."
IMPACT: A New Era for Maintenance Efficiency
Since the hydraulic test bench went operational, it has transformed the way the Cargolux team works. "Before, we repaired an actuator, painted it, and sent it to an external vendor for testing," Adrian explains. "Now, we can test it immediately after repair. If adjustments are needed, we make them right away — then paint once everything is validated." The process is not only faster but also more precise. "The bench is very accurate — much more than the analog equipment used on test benches when these actuators were first designed," Frank notes. Sometimes, he adds, the manufacturer's original specs are difficult to meet — not because the parts are defective, but because today’s ultra-precise measurements reveal even the slightest deviation.
Cargolux’s experience echoes what other MROs have found with modular automated test benches: dramatic efficiency gains. (Editor's note: MRO stands for Maintenance, Repair, and Overhaul )
Advanced automation also reduces human error, while transparent test chambers and an intuitive software interface give operators real-time control.
It’s a new era of learning and mastering in-house maintenance. "We are at the beginning of the learning curve," Frank says. "But having this capability gives us increased flexibility — not just for today’s needs but for the future too."
WHAT’S NEXT: Future Growth and Opportunities
The hydraulic test bench is more than a project completed — it’s a valuable asset to our Maintenance Organization for the future. "With the right software updates and new fixtures, we’ll be able to test the actuators of the future Boeing 777 fleet as well," Adrian points out. The modular design ensures that Cargolux’s investment remains future-ready, able to accommodate new test programs and requirements without major overhauls.
Looking even further ahead, Frank sees an opportunity: "One day, with our expertise and capacity, we could even offer hydraulic testing services to other companies."
But for now, the focus remains clear: ensuring that Cargolux’s legendary 747s — and future fleet — stay reliable, safe, and ready for the skies. At Cargolux, every test, every repair, and every innovation is powered by the same spirit: the pride of keeping the fleet flying safely.