Cost Index
Yeah, I know how it's supposed to work and I have read as many threads as I can find on the subject but bear with me.
My firm operate pretty full B737-800's about the Pacific on sectors usually around the 4 to 6 hour mark.
About a year ago in an effort to offset rising fuel costs a decision was made to move to a variable cost index (typically 6 to 10) rather than the CI30 that had previously been used. Possibly coincidentially an increase in PDA's was noted across the fleet at that time.
My dilemma.... I have found that operating at CI30, as best I can tell, achieves the same fuel burn or sometimes less (ref. the flightplan) with time savings of up to about 10-15 mins (obviously depending on the wind and sector length).
We use standard passenger weights and I don't want to go there but wonder if we are slipping up the other side of the curve.
Can anyone with any experience in this area shed some light or help me with what others have already concluded on this subject.
cheers