Outlook for Air Transport to the Year 2015 - FILT CGIL Foggia

Appendix 2MODEL FOR AIRCRAFTMOVEMENT FORECASTS1. The relationship between aircraft-kilometres, load factors and aircraft size (seats per aircraft) wasdeveloped for passenger aircraft as follows:Aircraft kilometres ==passenger-km(passenger-km/seat-km) • (seat-km/aircraft-km)passenger-km (1)load factor • aircraft sizeThe forecast for aircraft-kilometres for scheduled passenger aircraft in the year 2015 was generated bysubstituting into this expression the assumptions for passenger-kilometres, average load factor and averageaircraft size in the year 2015 (excluding the Commonwealth of Independent States for which some of the basedata were not available). The first of these assumptions follows directly from the traffic forecast presented inChapter 5.2. The average rate of increase in aircraft-kilometres from 2002 to 2015 implied by this forecast was thenused to calculate the forecast number of aircraft-kilometres for all scheduled services, including all-freight as wellas combined passenger and freight services (but excluding the Commonwealth of Independent States).3. The relationship between aircraft departures, aircraft-kilometres and aircraft stage length for passengerand all-freight aircraft combined is derived as follows:Aircraft departures ==aircraft-kmaircraft-km/aircraft departureaircraft-km (2)stage lengthThe forecast for aircraft departures in the year 2015 was generated by substituting into this expression the forecastfor aircraft-kilometres and the assumption for average stage length in the year 2015.4. Equations (1) and (2) can be expressed, approximately, in terms of the average annual rates of change ofthe variables over a specified period (e.g. 2002 to 2015).Equation (1) becomes:% (ac-km) % (passenger-km) % (load factor) % (ac size)Equation (2) becomes:% (ac departures) % (ac-km) % (stage length)where “ac” stands for “aircraft” and “%” stands for “average annual percentage increase”.49