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Branch Hydraulic Systems - landing gear test solution to Messier-Dowty

Branch Hydraulic Systems, specialist solution providers for the hydraulic power industry, have recently designed and supplied Messier-Dowty with a hydraulic fill and level solution, including the specification of MP Filtri ICM Units, for the new Airbus A350 main landing gear assembly project. 


messier dowty hydraulic power pack


Messier-Dowty, a Safran group company, is the world leader in the design, manufacture and support of landing gear systems. 

Following a stringent and in-depth evaluation process, Branch Hydraulic Systems were selected to supply a highly accurate hydraulic fill and level solution and component specification for the Airbus A350 main landing gear, with supporting working instructions, user guides and a long-term maintenance plan.

Forming an integral part of the production acceptance test for filling and levelling the landing gear and hydraulic pipe testing, Branch Hydraulic Systems specified three MP Filtri In-line Contamination Monitors (ICM), to meet the technical requirements for an in-line particle-checking device, working to ensure that only clean oil or fluid enters the landing gear.

These contamination monitors work alongside the MP Filtri high-performance filtration products, which provide the correct and consistent contamination control of the test rigs.

Mounted directly onto the system, the MP Filtri ICM unit automatically measures and displays particulate contamination, moisture and temperature levels in various hydraulic fluids, including Skydrol.  Messier-Dowty required the installation of two individual landing gear assembly hydraulic test rigs. This included the mineral oil rig of MIL-PRF-87257 for filling the landing gear; including a separate unit for mineral oil storage. The second test rig supports the testing of the hydraulic pipe system up to 5000psi, using a Skydrol unit for flushing and pressure testing the hydraulic pipework on the landing gear.

Alex Tatlow, Branch Hydraulic Systems technical director explained the decision to specify the ICM units: “We have been a distributor for MP Filtri, through our Group HES organisation, for around 20 years and have an established and trusting relationship with the MP Filtri UK team.  When we knew that the testing programme required a monitoring system that would not only detect solid contamination but one that would also highlight the presence of moisture, an anomaly in the particle counter market, we quickly identified that it required the performance of the MP Filtri technology.”

“We were also aware that Messier-Dowty required a counter that was compatible with Skydrol, a fire-resistant aviation hydraulic fluid.  With low viscosity Skydrol has poor lubrication qualities and is incompatible with a large number of seals and metals, leading to leaks; so being able to identify the cleanliness of this fluid is very important, especially as a failure on a rig is extremely costly.  With the additional development of a Skydrol ICM unit we were able to meet all of the requirements specified by the Messier-Dowty engineering team.”

Performance & Capability – both product and business

Branch Hydraulic Systems used two ICM models for the three installations; an ICM WMKOG1 for the mineral oil rig and storage unit and a specialised model for the Skydrol unit, an ICM OSKOG1.  The ICM WMKOG1 uses a standard unit with a six key keypad and a backlit graphical display for data readings, with water and temperature sensing and standard minimess connections.  The specification of the unit differs slightly for the ICM OSKOG1, with the unit not sensing water and temperature and being Skydrol compatible rather than mineral oil. 

Brian Roberts, the Messier-Dowty team leader for assembly methods, said: “Branch Hydraulic Systems have not only reacted and delivered an effective and highly accurate solution but Alex and his team have also provided very comprehensive operating and maintenance instructions, including test certificates and a breakdown of the components used with supporting technical data.  This data pack adheres to all of our business needs during the landing gear production assembly testing process, including operator guidance and training.

“Messier-Dowty is a forward-thinking company and we rely on the technical expertise and fast response of Branch Hydraulic Systems to select suitable components for the design of the corresponding test rig.  The new Airbus A350 main landing gear project is a high profile programme for Messier-Dowty.   We need new and proven technology to provide reliability during the production process and to also consider the environmental aspects of power and energy savings, as well as a run-time reduction: something that Branch Hydraulic Systems were able to deliver, without hesitation” said Brian.

Alex concluded: “Our in-house demonstration unit has allowed us to explore the advanced capabilities of the ICM unit, even using the USB connection to link to a PC or laptop and collate and print out the data readings.  There is nothing quite like this on the market.  It meets the exacting criteria of Messier-Dowty whilst managing to push the boundaries of engineering and technological development.”

A division of a leading hydraulic and fluid power company, Group HES, Branch Hydraulic Systems (Branch) is responsible for the design, manufacture, installation, repair and service of hydraulic power units and hydraulic power systems; with an in-house design and engineering team, headed up by Branch Hydraulic Systems technical director, Alex Tatlow.

For more information please call the team on 01452 730 562, email enquiries@grouphes.com or visit the Branch Hydraulic Systems' website