S.L. 333.1 Art. 4Calculation of the charge.

(1) The charge shall be calculated in Euro according to the following formula:

r = n x u where r is the charge for the flight, n is the number of service units relating to that flight and u is the appropriate unit rate specified in column 3 of the First Schedule.

(2) For the purpose of the preceding subregulation, the number of Service units relating to a flight shall be calculated in accordance with the the following formula: n = d x p where d is the distance factor for the flight in the specified airspace and p is the weight factor for the aircraft concerned.

(3) For the purposes of the preceding subregulation, the distance factor (d) shall be obtained by dividing by one hundred

(100) the number of kilometres in the great circle distance between: - the aerodrome of departure within, or the point of entry into, the specified airspace and - the aerodrome of first destination within, or the point of exit from, that airspace.

The aforeasaid entry and exit points shall be the points at which the lateral limits of the specified airspace are crossed by the route described in the flight plan. This flight plan incorporates any changes made by the operator to the flight plan initially filed as well as any changes approved by the operator resulting from air traffic flow management measures. However, for flights terminating at the aerodrome from which the aircraft has taken off and during which no intermediate landing has been made (circular flights), and for which the one most distant point from the aerodrome lies within the specified airspace, the distance factor shall be obtained by dividing by one hundred (100) the number of kilometres in the great circle distance between:

- the aerodrome within, or the point of entry into, the specified airspace, and - the most distant point from the aerodrome plus the number of kilometres in the great circle distance between: - the most distant point from the aerodrome and - the aerodrome within, or the point of exit from, that airspace. The distance to be taken into account shall be reduced by twenty (20) kilometres for each landing and take-off in the specified airspace and shall be expressed to two decimal places.

(4) For the purposes of the preceding subregulation, the weight factor (p) shall be the square root of the quotient obtained by dividing by fifty (50) the number of metric tons in the maximum certificated take-off weight of the aircraft as shown in the certificate of airworthiness, the flight manual or any other equivalent official document and shall be expressed to two decimal places. Where the maximum certificated take-off weight of the aircraft is not known to the bodies responsible for the collection of the charge, the weight factor shall be calculated by taking the heaviest aircraft of the same type known to exist.

Where an aircraft has multiple certificated maximum take-off weights, the weight factor shall be established on the basis of the highest maximum take-off weight authorised for the aircraft by its State of registration. Where an operator has indicated to the bodies for the collection of the charge that he operates two or more aircraft which are different versions of the same type, the average of the maximum take-off weights of all his aircraft of that type shall be taken for the calculation of the weight factor for each aircraft of that type. The calculation of this factor per aircraft type and per operator shall be effccted at least once a year.