EFOS captures and analyses valuable data about block times, fuel usage, route performance, payload, holding delays, on-time performance and aircraft efficiency. Subsets of this data can be made available to all EFOS users with more detailed analysis provided to managers. The data is useful for predicting route operating costs, identifying inefficiencies, refining flight planning systems, unnecessary fuel loading, crew duty times, EU-ETS, crew flight expenses and also provides crew with their own “Log book” of flights.