Wheels and Landing Gear

Although landing gear represents only 2.5% to 5% of the MTOW (maximum take-off weight) and 1.5% to 1.7% of an aircraft's total cost, it makes up around 20% of the maintenance cost of an aircraft during its lifespan. This is in part due to the extreme loads during take-off and landing, although additional factors such as temperature also result in a number of individual components requiring regular maintenance.

Ensuring landing gear operate efficiently throughout their lifetime is therefore vital, and Silmid provide a wide range of chemical consumables approved by manufacturers such as Safran Landing Systems and UTC Aerospace Systems.

Landing Gear and Shock Strut Fluids

The shock strut helps cushion the impact of landing and, by absorbing energy, damps out vertical oscillations and reduces bounce. The viscosity of oil inside the shock strut helps to dampen the rebound movement.

A range of speciality hydraulic fluids designed to absorb the immense pressure landing gear struts come under upon take-off and landing are available from Silmid for on demand shipment worldwide. These families include the Nyco Hydraunycoil FH 6 AW – approved for both Airbus and Boeing and applicable to storage and flight – as well as the AeroShell Landing Gear Fluid (LGF).

Wheel and Bearing Greases

The typical aircraft wheel is lightweight, strong, and made from aluminium alloy, although some magnesium alloy wheels also exist. Within the wheel, the wheel bearings are designed to take the load of the aircraft during take-off and landing, and it is important to service wheel bearings to prevent galling, overheating, and other problems that may affect the airworthiness of an aircraft.

Using the correct grease is vital to avoid such problems, and greases with extreme pressure, anti-wear and corrosion resistance properties such as AeroShell Grease 22 and the new AeroShell Grease 58 are perfect for any wheel bearing task.

Speciality Cleaners and NDT

Before any overhaul activity can begin, it is essential that all parts are thoroughly cleaned to remove used grease and other debris. Products such as the Ardrox 5503 Solvent Cleaner and the Socomore Diestone DLS are specially formulated and approved by landing gear OEMs to support in this process.

Additionally, Silmid carry a range of non-destructive testing (NDT) products covering both Penetrant Testing (PT) and Magnetic Testing (MT) technologies. These products are used to detect any defects in components prior to overhaul.

Corrosion Management

Although landing gear are one of the most durable components on an aircraft, their exposure to extreme conditions and forces make them vulnerable to corrosion and stress damage. If landing gear are not properly maintained it can reduce the operational lifespan and increase the overhaul cost.

Greases, lubricants and speciality compounds suitable to remove existing corrosion and actively prevent re-occurrence on the aircraft are available in a range of formats. As an example, Rocol AEROSPEC PROTECT Spray is approved by Airbus for use on the main landing gear axle sleeves.