747-400 econ cruise speed?
That's true enough, to a point....
How often is "occasionally"? and are you saying I don't understand "how and why" the plan was generated? If it's "not hard to beat" then please tell us why and how, and why airlines invest a lot of money & a lot of clever people work hard to generate these apparent works of fiction. YET AGAIN Cost Index is about minimum overall cost per hour, not just reducing fuel burn. I think 99% of professional pilots would agree the plans work very well on 99+ % of occasions. No deep thinking is needed flight planning wise from the pilot until something totally unexpected occurs which obviously cannot be planned for in routine ops. We used ARINC plans which worked out very well.
How often is "occasionally"? and are you saying I don't understand "how and why" the plan was generated? If it's "not hard to beat" then please tell us why and how, and why airlines invest a lot of money & a lot of clever people work hard to generate these apparent works of fiction. YET AGAIN Cost Index is about minimum overall cost per hour, not just reducing fuel burn. I think 99% of professional pilots would agree the plans work very well on 99+ % of occasions. No deep thinking is needed flight planning wise from the pilot until something totally unexpected occurs which obviously cannot be planned for in routine ops. We used ARINC plans which worked out very well.
Most of the times when we are filed at a high cost index it's because flight time is close to block time, and the company wants to show good on time arrival. At least half the time we are able to push a few minutes early, have a short taxi, get airborne, and I can reduce to CI15 and still be early. Reverse is true too. CI is a great tool, but if it not updated dynamically the pilot will definitely ba able to beat it often.
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Even a change of 40 makes a huge difference with a fleet of aircraft, all flying 4000 hours a year. Using your numbers each aircraft would use 33.3 tonnes more, or less, per year. Multiply that by the number of aircraft in the fleet.... see the point? BUT once again it's about total operating cost not just fuel burn & CI is set to minimise the total cost of that particular flight, taking all the circumstances into account.
This is also the reason that bizjets don't use CI, they only fly 400 hours a year on average and are individual aircraft or in a very small fleet compared to the airlines. The cost reduction for an individual jet would be relatively small. On the one I used to fly we had a cruise of 0.8 all the time, only using Mmr 0.74 on range critical flights because the fixed costs per hour were more than the cost of the fuel saved (aircraft only did about 250 hours a year)
It always amazes me how many pilots think that they are somehow smarter than the flight planning system. They are usually the ones that think they can "beat the odds in a casino" as well.....
This is also the reason that bizjets don't use CI, they only fly 400 hours a year on average and are individual aircraft or in a very small fleet compared to the airlines. The cost reduction for an individual jet would be relatively small. On the one I used to fly we had a cruise of 0.8 all the time, only using Mmr 0.74 on range critical flights because the fixed costs per hour were more than the cost of the fuel saved (aircraft only did about 250 hours a year)
It always amazes me how many pilots think that they are somehow smarter than the flight planning system. They are usually the ones that think they can "beat the odds in a casino" as well.....
I don't understand the logic or benefit of arriving early, as you say. I have to conclude that in order to arrive on time you were receiving updated CI's from the airline via ACAR's? and hence just entered the updated number into the FMS. If not you were just guessing. If you want to arrive early, (for no good reason) why didn't you just push up the fixed cruise speed in the FMS? (which makes very little difference unless its a very long sector) Once again how is any of that "beating the system" ? unless of course it gives an airline Captain a bit of an erection or wetness.....
My company wants us to depart and arrive on time, not early, not late. Due to the schedule being built months ahead of time, the winds and average delays used to calculate block times are just that, average. On the actual day of departure, when the dispatcher prepares for our specific flight, about 2 hours before departure, he has much better info on the delays expected and the actual winds, and route changes due to weather. He will plan accordingly, and come up with a CI that in combination with the expected taxi times will give us an on time arrival. Not early, because the gate will be occupied, not late because of "on time performance numbers". Plenty of times, after getting an early off block, and shorter than expected taxi, it turns out we would get in very early if we fly at that planned high CI, so I get in touch with dispatch, and we adjust it. The reverse is also true. That is why I said it would be nice if the CI would be automatically updated after getting airborne, and that is why we can "beat the system", meaning, we can get better on time performance than the outdated data would give., because the system isn't updated with the actual info. I would not get any updated CI if I didn't request them. And it isn't exactly guessing to bring down/up the CI till you see a landing time that when you add the scheduled taxi time gives you the on time arrival time. Not rocket science. And definitely not something that would get me exited...
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I will try to look past your past sentence, and answer again, but now in a way you might understand.
My company wants us to depart and arrive on time, not early, not late. Due to the schedule being built months ahead of time, the winds and average delays used to calculate block times are just that, average. On the actual day of departure, when the dispatcher prepares for our specific flight, about 2 hours before departure, he has much better info on the delays expected and the actual winds, and route changes due to weather. He will plan accordingly, and come up with a CI that in combination with the expected taxi times will give us an on time arrival. Not early, because the gate will be occupied, not late because of "on time performance numbers". Plenty of times, after getting an early off block, and shorter than expected taxi, it turns out we would get in very early if we fly at that planned high CI, so I get in touch with dispatch, and we adjust it. The reverse is also true. That is why I said it would be nice if the CI would be automatically updated after getting airborne, and that is why we can "beat the system", meaning, we can get better on time performance than the outdated data would give., because the system isn't updated with the actual info. I would not get any updated CI if I didn't request them. And it isn't exactly guessing to bring down/up the CI till you see a landing time that when you add the scheduled taxi time gives you the on time arrival time. Not rocket science. And definitely not something that would get me exited...
My company wants us to depart and arrive on time, not early, not late. Due to the schedule being built months ahead of time, the winds and average delays used to calculate block times are just that, average. On the actual day of departure, when the dispatcher prepares for our specific flight, about 2 hours before departure, he has much better info on the delays expected and the actual winds, and route changes due to weather. He will plan accordingly, and come up with a CI that in combination with the expected taxi times will give us an on time arrival. Not early, because the gate will be occupied, not late because of "on time performance numbers". Plenty of times, after getting an early off block, and shorter than expected taxi, it turns out we would get in very early if we fly at that planned high CI, so I get in touch with dispatch, and we adjust it. The reverse is also true. That is why I said it would be nice if the CI would be automatically updated after getting airborne, and that is why we can "beat the system", meaning, we can get better on time performance than the outdated data would give., because the system isn't updated with the actual info. I would not get any updated CI if I didn't request them. And it isn't exactly guessing to bring down/up the CI till you see a landing time that when you add the scheduled taxi time gives you the on time arrival time. Not rocket science. And definitely not something that would get me exited...
Hans, I think you're missing the point. CI was never intended to be used as an on-time departure/arrival tool. It's a designed tool to enable the cheapest way to operate the aircraft per flight hour when comparing a company's direct operating costs to fuel related cost. Adjusting the CI to enable better on time performance is like using chopsticks to eat soup, it might look like its working occasionally but you aint getting much soup.
Try the RTA function on the progress page if you want the best on time.
