Hey Kyle, if the plane is running late and a higher CI is required to catch-up to schedule, do they have to redo the fuel load?

Hey Kyle, if the plane is running late and a higher CI is required to catch-up to schedule, do they have to redo the fuel load?

 

Depends on how tightly they run fuel numbers.  Many operators factor in a certain amount of error in their fuel planning to accommodate stuff like this (contingency fuel - extra fuel en route factors, to include sub-optimal flight level restrictions, higher than forecast winds, changes in CI, etc).

I had a quick rant about this in a couple of my videos:

 

CIs change.  While many operators have a value that's a default, it's normally only used in cases where they - either intentionally or accidentally - do not provide a value on the load sheet.

 

-If the flight is delayed on departure and there's still a chance to get there on time, they'll raise the CI to go faster and get there on time.

-If they're expecting delays at the destination, they may dial the CI back to just get there at the end of the rush.

-If the flight has a ton of Premiere Members (or whatever the airline calls them), they may actually dial the CI up to get them there early.

-If the price of gas goes up, the CIs often go down.

-Certain routes will have higher CIs, while others have lower CIs (based on average revenue gained on that segment).

 

There really isn't a standard value for airlines in all cases.  Despite what many will claim here, it's not as static as many would have you believe.

This was very helpful for me as i do get a bit thick on this subject thanks Kyle

This was very helpful for me as i do get a bit thick on this subject thanks Kyle

 

Glad it helped!

Glad it helped!

Yeah it did i love flying and like most my dream would be

to actually do it but i can never see that happening which is why most of us love flight sim.

in emirates we used 70

 

Thanks. Is this both on the pax and cargo side?

In Air New Zealand we use 50

 

Chris Finlay

AA used 20 for Chicago-Rome one time, yea it was on a 763 but that's still pretty low.

AA used 20 for Chicago-Rome one time, yea it was on a 763 but that's still pretty low.

 

The AA Boston-Rome flight is part of my favorite youtube video

 

 

 

The AA Boston-Rome flight is part of my favorite youtube video

 

Yep and that guy's channel has many interesting vids.

Depends on how tightly they run fuel numbers. Many operators factor in a certain amount of error in their fuel planning to accommodate stuff like this (contingency fuel - extra fuel en route factors, to include sub-optimal flight level restrictions, higher than forecast winds, changes in CI, etc).

Maybe worth noting.

Once you are flying, the rules about fuel change a bit. For example, you cannot calculate with using contingency before you lift off (for taxi for example), but you can use it to speed up once airborne...

haha - some of it is valid, to a certain degree, if I understand the VNAV handling of CI correctly:

Higher CIs drive higher descent speeds, which makes slowing down prior to and on the approach more difficult.  I could be massively wrong, however.

 

In the end, though, you're right - it's used too often as the answer when it shouldn't be.

It's also worth noting that some airlines use different CIs for climb, cruise and descent, which might help with that problem.

 

At it's core CI represents the cost of fuel vs the other operating costs of a flight hour. Low CI is chosen when fuel is expensive, high CI when other operating costs are high (high maintenance costs, delays, etc). Note that other operating costs can include more intangible things like upsetting your frequent flyers by arriving late.

 

Boeing has a good article on choosing CI here: http://www.boeing.com/commercial/aeromagazine/articles/qtr_2_07/article_05_1.html

in emirates we used 70

 

You might need to be more specific than that. As people have already pointed out, yes it is variable, but it's specific to the aircraft operating. There's no single CI used for all flights operated by a given airline, unless of course all the aircraft they own are the same type. These are the most up to date CI figures for Emirates. I randomly pulled up some flight plans today and copied the figures straight off.

 

EMIRATES:

A330-200: CID 26

B777-300/ER: CID 35-37

A380-861: CID 60

B777-200LR: CID 35-37

CIs are company things. Based on each plane itself, too. Many many factors play a role in this. You can see that this airline use this CI the next use this the next use this... An engine get less wear in life time. Old engines don't have the same efficiency like new one. They have only eg 96 or less. This engine weariness will take the higher bill, too.

 

There are so many company depended things, aircraft itself and many other factors to calculate CI.

 

If some guys post here CIs you will see that this airline with same route use on a different plane a complete another CI. Ask real life FO or Captain. They will tell you the same.