Cost Index

[davjg 32]

HelloFirst I want to say MD-11 is a beautiful bird and I dont understand how anyone can complain about it, since nothing is perfect. But compare to other products that out there, PMDG is a that few stands out far better in quality and customer service support. Anyway, I have a question regarding Cost Index, is there a chart for this where I need to input this number correctly? recently I simply am using "60" but i know this figure is simulated into your flight, thanks.

[Guest XM DUDE]

Yeah I have always wanted to know what that means too.Michael Pare.

[Guest Callmecapt]

The cost index determines how much fuel is burned and how fast you go. It does get a little more detailed but you can read about it in any of the pmdg manuals.TOPCAT can recommend a cost index value I think. Airlines typically use a number between 50 and 150. Goran

[Shmiffy 0]

As Goran states:Cost index is potentially a long and very boring subject, i would venture a suggestion that a CI of 50 to 60 is abit low.I have been flying at 90 (same as BAW real world 744 ops) and have been getting cruise speeds of about .828 Mach. for my next couple of flights i would like a bit more speed, and the fuel is free, so i shall up that number to 100 or 120 and see how we do.It would be interesting to know what the RW operators suggest though.Normally the Perf Data in the FCOM would be a useable source to determine an appropriate CI using the Cost Index Table, but as there have been many discussions here on the Forums, we know that Boeing, for whatever reason, are unwilling to release the full Perf Data that the FCOM should have. CI therefore is going to be a case of trial and error, but for me, 90 is working quite well, i expect 100 to be suitable for me though, and i shall try it out on CTP tomorrow. CheersPaul

[3-2-1-Now 126]

Hi,In short, the higher the CI, the more it costs to fly, so the FMS flies accordingly (faster, generally). To compute the CI however is a whole subject on its own.Best regards,Robin.

[Guest XM DUDE]

Interesting, I've been dialing 88 on everything I fly.Michael Pare.

[davjg 32]

Wow!, I didnt think it was a whole new subject of it own. Thank for the tip guys, I guess I will go with 90, I appreciate it.David Guillen

[VHOJT 150]

Just pointing out the obvious here but CI on the 744 does not hold any relationship to cost index on the MD-11. Unless there is coincidence, the same "number" in each will mean different cruise speeds.

[stevenp 1]

I usually go with 80, I heard that 80 is the standard and will get you the standard cruising speeds. So far its worked well for me.

[Check_Airman 3]

>Normally the Perf Data in the FCOM would be a useable source>to determine an appropriate CI using the Cost Index Table, but>as there have been many discussions here on the Forums, we>know that Boeing, for whatever reason, are unwilling to>release the full Perf Data that the FCOM should have. In Boeing's defense, I've never seen a CI table in any manual. The airline will determine what CI will be used. They vary WIDELY. You'll find 2 airlines operating the same plane with very different CI's. For example, I'm told one major 767 operator uses CI of ~13 for their 767's. Another carrier uses one in excess of 500.Find an airline you like, and use whatever CI they use. There's no wrong or right CI.Paul

[phil747fan 14]

Paul,i agreed with you but since 777 LR and 300 ER have been released this is no more true in the FPPMs there is now some infos on CI180 and CI150 but this for the 777 ....i ve seen charts too for 744 including CI100, CI120 and CI150 but it was tailored for specifics ops not released in FPPM and available only on crew manuals ...just my two cents.phil

[phil747fan 14]

>I usually go with 80, I heard that 80 is the standard and>will get you the standard cruising speeds. So far its worked>well for me.This is the one with datas i have too for PW engines so seems this what they used but long time ago dont know for now ...!!Phil

[Guest jbos]

When the price of oil goes up, lower your cost index to save fuel. When you (the pilot) or your flight attendants renegotiate higher wages, then raise your cost index to shorten the flights.

[Guest Shaun48113]

I just use 45 on everything. I don't know if its realistic (I heard that one operator uses 45 on its 757/767 fleet), but it seems to do a good job of conserving e-fuel. :)-Shaun

[michal 44]

>Just pointing out the obvious here but CI on the 744 does not>hold any relationship to cost index on the MD-11. Unless>there is coincidence, the same "number" in each will mean>different cruise speeds.This is perfectly understandable. The only way to compare CIs on different aircraft would be to compare how they perform with respect to optimal fuel burn. Assuming for example that index 0 gives you the longest range on every aircraft - the index say 50 should give you similar percentage increase in fuel burn over the optimal one (I am speculating here that this may be the case) but the respective speeds of course will be different.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg