You rest a lot of money on top of your jack. Millions of dollars. Unfortunately, you can’t tell that your jack is going to fail on you just by looking at it. If you’re working on your plane and the jack leaks, how will you get your place safely back on to the ground? Jack failure is a tight situation that you never want to be in.

There are a few different reasons causing hydraulic aircraft jack failure:


A seal failure in hydraulic jacks can cause a leak and cost thousands in downtime. There a few reasons that a seal can fail. The first is that it was improperly installed in the first place. One of the most common installation errors is installing the seal upside down. Chemical breakdown of the seal is another common problem that causes the seal to swell or leak, most often caused by misapplication of chemicals causing oxidation.


Contamination of the cylinder is a difficult scenario to prevent. Minute details that are barely visible to us, such as dust or dirt, can throw off the system components. A more visible contamination would be the appearance of rust or ice.


If a check ball is not seated correctly, the lifting mechanism of the jack could fail. Either the jack simply will not lift up what it is expected to or it could fail in the middle of servicing. This could have catastrophic consequences for workers. If a check ball is not seated correctly or is not working properly, it should be replaced.


A simple dent on the leg of a tripod jack could cause the jack to fail. The leg could give out and collapse while lifting a plane, also having catastrophic consequences. If a jack is not given a thorough inspection, an unnoticed dent could cause a jack to fail.

The best way to tackle jack failure instead of blindly wandering through the dark is to do regular proof load testing. These tests ensure that the details you can’t see, either inside or outside of the jack, are up to par. In order to have a high quality maintenance facility, you must have guaranteed safety while using jacks. Jack proof load testing is the key to safety.

How should you maintenance your jack and how do you pick a calibration lab?
Find out in this guide