Hydraulic Ground Support Equipment Maintenance Guide

First, airports want to ensure a company-wide agreement is in effect to support new contamination control programs. This will include acknowledging all things related to the new initiative, including the necessary costs, training, equipment, materials and manual labor.

Next, airports will want to set up in-depth contamination training for all ground support personnel to start the new program on the same footing. Training can be supplied by the equipment manufacturer, a hydraulic training center or a school of engineering. This will ensure that all ground support personnel have the proper knowledge and skillset to keep hydraulic ground support equipment in pristine working order.

Next, airports can begin to put fluid-level contamination standards into place for all ground support personnel to follow. Acceptable levels of contamination should come from the airframe tooling manufacturer's recommendation. But we'll touch more on this a bit later.

Once ground support personnel is trained and a fluid level contamination standard is in place, airports can transition to baseline testing of all hydraulic ground support equipment present. Personnel can send a fluid sample to an analysis laboratory or use a contamination monitor to find baselines.

At this point, airports can acquire any and all equipment and materials needed to implement a contamination control program. This can include but is not limited to the following:

Finally, airports will be ready to schedule regular GSE maintenance and hydraulic ground support equipment testing. Personnel should set up specific intervals for testing and filter replacement and periodic evaluations of the program itself.

When inspecting fluids, begin by ensuring the fluid filler cap is in good working condition. This cap should only ever be removed when servicing the reservoir. A hydraulic ground support equipment fluid reservoir should typically be a sealed type with an air filter and desiccant to control the fluid's overall condition. If air filters and desiccants are not currently in place on hydraulic ground support equipment, airports can add them to existing reservoirs.

It's recommended that personnel regularly monitor fluid to ensure it meets the required specifications of the airframe, fluid or component manufacturer. Monitoring consists of taking a fluid sample and sending it to an analysis lab or using a portable contamination monitor. This monitoring process allows for consistent adjustments of contamination control and GSE maintenance programs to keep contamination at an acceptable level.

Using portable monitors to get immediate results of the ISO or NAS cleanliness level allows personnel to inspect hydraulic ground support equipment with top-of-the-line precision. The monitors allow for precision gauging of the cleanliness level and the moisture level within the fluid system. Personnel is then recommended to use a portable filtration and moisture removal unit to bring these down to more acceptable levels that conform with manufacturer recommendations.

Another method for maintaining acceptable levels is to off-line clean hydraulic fluid systems. Simply loop fluid through an onboard or kidney loop system until the levels have reached an acceptable point.

Personnel must change GSE filters regularly based on manual recommendations to maintain the required contamination level of the systems. This should be done, at a minimum, on an annual basis. Depending on usage, it may need to be done more frequently. When monitoring the air filter and desiccant, ensure that they're not saturated. This could limit air from exchanging with the reservoir or even allow contaminates to enter the reservoir.

To take advantage of new, more efficient filter designs, consider upgrading the filtration systems of hydraulic ground support equipment. Personnel should carefully choose filters that can handle the required system flow and pressure.