Tronair HPU preventative maintenance

Hydraulic power units are a major piece of equipment used for aircraft maintenance. Many components within an aircraft consist of a hydraulic system that is vital for control and operation. Hydraulic power units provide pressure to these hydraulic systems during maintenance to ensure that all hydraulic systems are functioning properly and accurately. It is imperative for a hydraulic power unit to be operating efficiently to ensure that the hydraulic system within an aircraft is being maintained and repaired accordingly. In order to make certain a hydraulic unit is in tip-top shape, frequent calibration and maintenance must be performed.


A hydraulic power unit consists of a handful of gauges, such as a system pressure gage, a hand pump pressure gauge, a crossover pressure gauge, a back-pressure gauge and a pyrometer temperature gauge. It is necessary to calibrate each of these gauges to ensure that the pressure and fluid intake within the hydraulic unit is accurate and precise. Risks of not calibrating these gauges include:

All of these risks could also cause safety issues for anyone associated with the aircraft, along with financial distress. If a hydraulic power unit is not calibrated, chances of an aircraft’s hydraulic system failing are high. This would result in failure of landing gears, flaps, flight controls and brakes. Although hydraulic power unit calibration can be pricey, it is cheaper to ensure overall accuracy and safety of equipment than to pay for the damages of an aircraft due to equipment error.


Other ways to ensure a hydraulic power unit is working to the best of its ability is to frequently maintenance the unit. When caring for a hydraulic power unit, consider the following:

What should you be doing to maintenance and extend the life of your HPU?
Find out in our guide.