Cost Index Explained (Boeing PDF)

[stevekirks]

Found this while searching for FCOMs and other PDFs for the -300

http://www.boeing.com/commercial/aeromagazine/articles/qtr_02_10/pdfs/AERO_FuelConsSeries.pdf

Great article on cost indexes direct from Boeing...

Steve

[Shifty]

Great info Steve, thanks for this. 

I worked in flight planning before I went flying and found that on the Classic a cost index over 100 would just burn more fuel and save you pretty much no time. I found CI 70 to be a good figure if you are running late and want to make up time. 

Also a CI over 100 puts your speeds right up next to the VMO/MMO and can be very dangerous in even smooth but variable winds in flight. Our company sometimes tries to give us a CI of 150 and doesn't really think of what this will command from the aircraft, and how close to the margins it puts us. As airmen we will reduce our speeds as appropriate to give ourselves a margin of safety, This prevents us having to fill out an "air safety report" for over-speeding :-).

 

Shifty