I'm flying for Virtual Scandinavian and I get the CI with the dispatch. Most of the time its 12. Some conversations with real SAS crews by some of our members showed that they mostly use CI 6 in the 737 and change it during the flight to higher values if needed.

Boeing Aero did a great job on this for cruise fuel.

 

http://www.boeing.com/commercial/aeromagazine/articles/qtr_4_07/article_05_1.html

 

the closer you can get to doing exactly what your real world counterpart would do, and the closer the results of your actions match the results the real world pilot would expect in the same circumstances, then the closer what you are doing is to reality and the more satisfying it becomes.

There's some expectation that there's some magic number that airline X uses, and it's just not so. It can vary. It can be a range. It can change day by day. The real world counterpart can change things.

ryanair use CI=6

Someone explained pretty well: In simulator fuel is free, while your free time is very valuable, so use as high CI as aircraft accept.

KLM uses 6, 7 and 9 (737, 738 and 739, 1 year old figures). In general cost indices are very, very low these days, at least for European carriers.

Someone explained pretty well: In simulator fuel is free, while your free time is very valuable, so use as high CI as aircraft accept.

If you're into nitpicking realism you could of course fly as short of a route as you have time to fly with a realistic cost index.

If you're into nitpicking realism you could of course fly as short of a route as you have time to fly with a realistic cost index.

I can compare this with Real weather: If you fly with real weather you set QNH at correct value for example 1020hpa, but if you fly with clear weather FSX preset, you do not want to set QHN to 1020hpa because no matter if at real airport that is correct value, in your sim is not, and you set QNH to 1013hpa to match weather configuration of your FSX.

So as in FSX we are not charged for fuel (yet), and we are not payed for what we do, RW CI some airlines use, is incorrect. In fact CI cannot be incorrect, I should say inefficient. Just my opinion.

I can't answer for all airlines, but a lot of them do have standard values that are generally "use this if we don't state otherwise."  Many (from my understanding - at least in the US) do provide values for each flight that override those values.  Airlines are complex beasts, and each flight has its own motivation.  Flights that are continuing flights, or have tighter connections are going to have a higher CI.  I can nearly guarantee that any airline so equipped will change the CI for various flights.  The static numbers are simply the default values in case one isn't thrown in with the paperwork for that specific flight.  I'm not going to say all airlines do that, but I highly doubt an airline will always use a particular value.

 

It's important to note, as well, that in an RTA (required time of arrival) environment, many modern aircraft achieve RTAs through modulation of the CI.  The transition in the future (at least right now) is from ground delay programs (holding you at your origin to make sure you're not at your destination before a specific time), to RTA.  Basically, ATC says "be at FIX A at Time T."  You can depart whenever you'd like, and then toss in an RTA to tell the plane "put me at FIX A at Time T."  The plane then adjusts the CI accordingly.  How that's all managed behind the scenes in the automation, I have no clue.

 

Quick info on RTA.

I think it probably does vary a bit with some of the outfits. I remember back at one point

Southwest was supposed to be running a pretty low CI. But I'd seen videos where the

speeds they were running, tended to suggest they were using a tad higher CI than what

many were claiming. After a while, you get to where you can guess pretty close about

what speeds you will run after using the various numbers for a while.

Myself, I'm not ultra picky about it. Some of the pseudo Southwest flghts I've run 30.

Some 36.. I don't really like running lower than 30, because I like to come in a little on the

hot side if anything..

With my 700 BBJ's, I'll often run 40. With my 600 BBJ, I'll often run 45. Jet A is free in the

land of the sim. 

I've tinkered with the high numbers too.. I ran a pretty high CI when I first got the plane.

IE: 60, 80, and even tried 99 one time fer grins. Had no problems..

I  disagree with some who claim a high CI leads to ruination on the approach.

Not if it's working right.. That is taken into consideration, and planned for with the high CI

numbers.  Normally, everything should come out fine, even on a short trip.

Of course high CI will not ruin approach, aircraft software is designed to handle whole CI range with ease.

Unless I'm mistaken, CI should have no impact below 10,000'.

 

That's one thing that makes me laugh when people say things like. "I couldn't do approach XYZ" and someone repsonds "Well you should be running CI of 4 for that airline!" :nea:

 

I've tinkered with the high numbers too.. I ran a pretty high CI when I first got the plane.

IE: 60, 80, and even tried 99 one time fer grins. Had no problems..

I disagree with some who claim a high CI leads to ruination on the approach.

Not if it's working right.. That is taken into consideration, and planned for with the high CI

numbers. Normally, everything should come out fine, even on a short trip.

 

Once you get to that range for CI number you are reaching the upper edge of the envelope for the 737, once you get past 50 or 60 or so , or you could go all the way up to 999, but you are already near the barber pole in all phases. A 747 or 777 will have a higher useful range of numbers.

I wonder what CI BA used on their Concorde fleet ?

 

Eric W.

 

I wonder what CI BA used on their Concorde fleet ?

 

I am pretty sure there was no concept of "CI" back when Concorde was made...

 

 

 

That's one thing that makes me laugh when people say things like. "I couldn't do approach XYZ" and someone repsonds "Well you should be running CI of 4 for that airline!"

 

some folks have problems keeping up with the VNAV path on high CI. They would end up way too high.

 

Still, this is not a CI problem, but a bad technique problem, more visible on higher CI. No CI will be problematic for a pilot who does what he should, how he should. Up to 200 (IIRC for NG)

...

I wonder what CI BA used on their Concorde fleet ?

 

Eric W.

Concorde didn't have an FMC. It had a flight engineer instead

Unless I'm mistaken, CI should have no impact below 10,000'.

 

That's one thing that makes me laugh when people say things like. "I couldn't do approach XYZ" and someone repsonds "Well you should be running CI of 4 for that airline!" :nea:

Yep. Anything below 10,000ft is all speed management and flap deployment schedule. Even at cost index 99 the VNAV will be trying to place the aircraft 1: at 250kts or less below 10,000ft and 2: on profile so that it crosses middle marker at about Vref+5. Of course it can't slow down beyond the flap extension speeds till the flaps are positioned, so even though it might want 162kts with flap 15, it won't reduce past (example) 198kts with the flaps up.