Meta-analysis A procedure to cumulate findings from a number of validity studies to estimate the validity of the procedure for the kinds of jobs or groups of job and settings included in the studies. (SIOP, 1987). Meteorological Information Meteorological reports, analysis, forecasts and any other statement relating to existing or expected meteorological conditions. Meteorological Office (Aeronautical) An office designated to provide meteorological service for international air navigation. Meteorological Report A statement of observed meteorological conditions related to a specified time and location. Metering Metering is the calculation of target times (amount of times to lose or to gain) in order to meet scheduled arrival times at a defined constraint point, (Metering Fix, RWY threshold etc.) based on a pre-defined sequence and the arrival interval (i.e. the rate at which the corresponding aircraft will pass through that fix). Methods and Tools to Assess IMPACT on Future ATM Systems The IMPACT Project deals with issues in managing the transition towards the future ATM systems from a human factors point of view. It provides a methodological framework as well as analysis support tools dedicated to concept design, requirements formalisation, system design and training design. Through this material IMPACT proposes a coherent process based on change analysis to deal with HMI in the design process for future ATM systems. Microwave Landing System A microwave-based instrument approach system intended to replace ILS in the 1990s and claimed to offer a number of advantages such as the ability to fly segmented and curved precision approaches. Middle East Region See ICAO Region. Middle Marker Marker Beacon located where the centre of the glide slope is 200 ft above the runway. Middleware Middleware provides a set of horizontal services for the management and distribution of information, events and components. Milestone Significant checking point to assess the achievements of actions undertaken. A milestone has only two possible statuses: not passed or passed. Minimum Fuel Note: This is not an emergency situation but merely indicates that an emergency situation is possible, should any undue delay occurs