The operator shall ensure that the pre-flight calculation of usable fuel required for a flight includes:
(1) taxi fuel;
(2) trip fuel; (3) reserve fuel consisting of: (i) contingency fuel; (ii) alternate fuel, if a destination alternate aerodrome is required; (iii) final reserve fuel; and (iv) additional fuel, if required by the type of operation; and (4) extra fuel if required by the commander.