Calculating the flight's cost index

Prior to flight the airline calculates the cost of time and the cost of fuel in order to calculate a “Cost Index” that will achieve the minimum total cost of the flight. For a longhaul flight the Cost Index for minimum total cost is close to speed schedule for minimum fuel burn. The “penalty” in terms of fuel is in the order on 0.2 to 0.4% of total fuel burn.

CALCULATION OF COST INDEX

Over time the cost of fuel has seen a reduction in the optimum Cost Index. In 2005 the Cost Index across all aircraft within the Air NZ fleet were reduced and as a result, today our aircraft fly slower in comparison to earlier years. Air NZ introduced the B777 in 2005 at an optimum Cost Index. Relative to the policy that would have applied prior to 2005, the fuel saved on today’s flight from the use of a slower Cost Index is 90 USG = 860 kgs reduced CO2 emission.

 

 

Flight Phase Information