Maintenance Free Landing Gear

Prof. Rob Dwyer-Joyce
Messier-Dowty Ltd.

Thud of the landing gear, which signals it’s safe for the pilot to touch down. Less familiar though is the time consuming maintenance process needed to keep these gears working.

A landing gear has around 24 pin joints and the whole aeroplane around 300 greasing points, each of which must be individually hand greased. Failure to do so may lead to the landing gear sticking – requiring it to be winched open by hand.

This project, which is run in conjunction with Messier Dowty, is designed to enable these joints to last longer between greasings. Current processes mean the joints must be greased every 500 openings. Using a  pecially designed test rig, we are experimenting with different types of surface coatings and lubrication to find out how we can extend this time.

Of particular significance is the bush ring on the bogie – or wheel chassis. Runways are not flat, indeed some are significantly worse than others. This means that the bogey joint is repeatedly tipped, under high load, as the wheel passes over bumps.

The design of the pins is therefore crucial and our expertise is helping to meet this challenge.