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Old 27th October 2006 | 14:21
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From: Somewhere between here and there
777 Cost Index

Our airline has recently emberked on a fuel saving intiative. One of the major changes that has come from this is the change of cost index. On the 777 it translated to a change from 120 to 14. This results to a cruise speed of around M.81 vs M.84. One a couple of occasions, I have had controllers in Europe ask us to confirm our aircraft type because of the speed and even one asking if there was a problem!

I just wanted to know from other 777 pilots out there what cost indexes and/or cruising strategies/speeds you are flying?

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Old 27th October 2006 | 16:43
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14????? So you are basically flying at MRC, i guess that your crew costs and mx costs are extremely low. For obvious reasons you cant compare cost indices between airlines but we have played with CI=450 outbound and CI=80 inbound, for the sake of the environment, we settled on CI=80 for all international sectors. (CI is revised on monthly basis)

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Old 27th October 2006 | 19:41
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Although our flight planning software is reasonably sophisticated, the schedules/slots/stands take priority and we seem to fly at 0 when we're going to be too early and 100 when we might be on time or late. There was a period when we were planned at .85/320 (.87/330 Mmo/Vmo) down to South America to try and avoid having an extra crew member... didn't work very well through the ITCZ.
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Old 27th October 2006 | 20:17
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CI 50 with an option/recommendation to modify descent 82/300 if more appropriate.
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Old 28th October 2006 | 22:22
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Could it be US and European cost indicies use different units? Or do Boeings and Airbuses both use kg/min? Anyone know for sure?
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Old 29th October 2006 | 02:39
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It doesnt matter if you use Lbs or Kgs in the formula provided that you maintain the same units across the formula.

We use Kgs for most of our Boeings.

Mutt
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Old 29th October 2006 | 03:03
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We us CI = 85 for all operations, with approval to bump it up to 150 if running late. On average, it comes out at about M0.835 for cruise at or close to Optimum level.

Mutt, I would have thought that operators from certain oil-rich countries would have used CI=9999

Regards,

Old Smokey
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Old 30th October 2006 | 00:52
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From: A GOOD PLACE TO FLY, DRINK, **** AND SLEEP.
Some nut in our company has changed the sop to CI=0 for the climb and typically CI=100 for the cruise. I personally can't understand why. There is a good reason for flyin CI 0 and a different one for flying CI 100.

Among other things it really messes up the eta on the fmc during the climb. Since our flight plans are typically based on CI100 they don't make any sence or correlate till we insert 100 at the top of climb.

Maybe someone could help me understand why this is a good idea.... Before I pull any more hair out!!!
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Old 30th October 2006 | 03:01
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I would have thought that operators from certain oil-rich countries would have used CI=9999
Tried it.... interesting to see a B777 cruising at M860-865..... Got quite a number of questions about aircraft type

The idea of burning lots of fuel just because its cheap isnt an environmentally friendly concept, so we ignore our home base fuel costs and use external costs in the calculation.

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