Fluids are on the radar

Inspection of all on-board fluids

There is a wide range of fluids in various systems on board a modern aircraft, including hydraulic fluids, oils, fuel, and potable water. Motor oils and hydraulic fluids, in particular, have to fulfill specific requirements which vary according to the exact usage. These fluids must therefore be subject to regular prescribed inspections of their quality and usability. At Lufthansa Technik's Laboratory Services Department in Frankfurt, personnel analyze the fluids in terms of their chemical and physical properties and check for contamination.

Key parameters for a precise description of the condition of motor oils and hydraulic fluids include appearance, acid number, density, water content, electrical conductivity, and viscosity. Viscosity, for example, is a measure of the thickness of a fluid. The higher the viscosity, the thicker the fluid, and vice versa. Chemical changes, for example after overheating or caused by contamination with a fluid from outside the system, can have a negative influence on the viscosity and thereby significantly impede the operational functionality of the on-board system in question.

Regular microbiological inspections of fuel samples from customer aircraft are also carried out in the Frankfurt laboratory. Contamination of fuel, for example with microbes, can lead to corrosion in the fuel tank and fuel pipes and hoses. It is therefore important to identify such contaminations early and respond to them quickly, as they can otherwise result in much higher costs for the airline operators. It can also happen that a mechanic sends an unscheduled sample to the laboratory with a note that the oil level in the tank is too high. This could be caused by a leakage in the fuel pipe. To find out precisely what is happening, a contamination analysis is conducted in the laboratory. This facilitates a qualitative and quantitative analysis of the mixing of on-board fluids, which makes it possible to determine how much of which oil has entered the fuel supply or vice versa.

The large number of possible causes give rise to an accordingly large number of test procedures, some of which are very complex. A high level of automation in the laboratory means that all tests can be carried out reliably and at short notice; in special cases (AOG), they can even be completed in a matter of a few hours. The immediate proximity of the laboratory to flight operations on the apron of Frankfurt Airport is of decisive significance here. In addition, the special Laboratory Information Management Software (LIMS) helps in the precise documentation of all measurements and test results. Analyses that cannot be carried out in-house at the Frankfurt laboratory are provided at short notice by other accredited partner laboratories.

Customers of the Laboratory Services Department include, of course, the Lufthansa Passage Group, the Maintenance Division, and other Lufthansa Technik divisions. But external companies, such as customers of Lufthansa Technik Maintenance International (LMTI) and other airline operators and maintenance providers, also make use of the services of the Frankfurt laboratory. For some laboratory services, as much as 50 percent of work is already carried out on behalf of external customers. The demand for rapid and reliable laboratory services, tailored to maintenance operations, has been constant for many years.