Cost Index

[Fliifast1]

Our company uses a fixed CI on all flights and I find that odd. When we first got the planes we would play with the numbers to see what if, but now all fixed. Does anyone know or use a flight plan system that veries the CI for saving money. Direct cost/fuel cost? In corporate aircraft we knew the numbers and fuel costs so we could operate the aircraft for the lowest cost per flight segment! Airlines hummm?

B737-800's

[mutt]

After doing a flight analysis program, we opted to use a single figure Cost Index for 3 reasons.

1: Crew convenience
2: Very little difference between cruise speeds and fuel savings within the small band of Cost Index values that would be used for our route structure.
3: B744 fleet actually LOST money by using Cost Index rather than a constant speed!

Mutt

[Henry VIII]

Does anyone know or use a flight plan system that veries the CI for saving money

Jeppesen, SITA those I am aware of.

we knew the numbers and fuel costs

The most important number in CI calculation is the hourly cost of the aircraft. Difficult to calculate from the top floor guys too.

Last but not least, mind to manage the speed as close as possible to the manufacturer project philosophy. I mean, sometime flying CI you cruise at lower speed than optimal, increasing your AOA and producing longher flight time and increased fuel consumption.

HVIII

[Intruder]

The most important number in CI calculation is the hourly cost of the aircraft. Difficult to calculate from the top floor guys too.

The exception here is in ACMI contracts. There, the customer has an EXACT cost per hour for ALL operating costs except fuel, and he has a good idea of fuel costs. Using these numbers, a rather precise optimum CI could be calculated.

[BAe 146-100]

The average fixed CI on Boeing units seems to be in the 20-40 margin.

Some operators use different cost index's for different airfields.

146

[Henry VIII]

Totally agree, Intruder.

See also here.

HVIII