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FMC Cost Index Values

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FMC Cost Index Values

Old 29th Apr 2014, 15:33
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FMC Cost Index Values

Minor thing but, anyone know why some Boeing FMC's can only go to 999 while others are designed to go as high as 9999?
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Old 30th Apr 2014, 01:24
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Inflation? Currency conversion?
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Old 30th Apr 2014, 21:08
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Originally Posted by No Fly Zone View Post
Inflation? Currency conversion?
You mean like vs $?
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Old 30th Apr 2014, 23:40
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Cost index ranges for the various Boeing models:

737-3/4/500: 0-200
737-6/7/800: 0-500

747-400: 0-9999

757/767: 0-999 with Honeywell 200K and 700K FMC or 0-9999 with Honeywell non PIP, PIP and Pegasus Pre-2009 and Pegasus 2009.

777: 0-9999

Taking the 757 and 767 as examples. the original Honeywell 200K and 700 FMC's only had capacity of 200,000/400,0000 words and 400,000/1.4MB bytes capacity. This was insufficient memory capacity, to store CI values on a range of 0-9999.

When Honeywell's 1Meg/2meg 757/767 FMCS were introduced (originally Non-PIP FMCs which some airlines updated with the PIP software) with 1,000,000/2,000,000 words and 2MB/4MB bytes capacity the FMC now had sufficient memory capacity for CI values in a range of 0-9999.

The original Honeywell AIMS 1 on the 777-200/ER/300 had a 1,000,000 word and 2MB byte storage capacity. this being sufficient for storing CI values from 0-9999. This being the same capacity and available CI range of values on the Honeywell 747-400 FMC.

With the introduction of the 777-300ER and -200LR the Honeywell AIMS 2 upped memory capacity to 6,000,000 words and 12MB bytes.

The Honeywell 787 FMC has 15,000,000 words and 30MB byte storage capacity.

The Honeywell NextGen FMC, used on the 747-8 has 50,000,000 words capacity and 100MB bytes storage.

To sum it up, under 1,000,000 words and 2MB bytes storage capacity, the FMC could not store sufficient values to go beyond a CI range of 0-999.

The 737NG being the exception as Boeing never bothered to go above a CI range of 0-500.
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Old 1st May 2014, 05:48
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Inflation? Currency conversion?

I literally laughed out loud at that one.

Incidentally, I can see the utility of 99 vs 999. I can see how the ECON speed can be fine tuned via increased CI sensitivity.

For other FMC's, what's the difference in cruise speed between CI 9999 & 9998?
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Old 1st May 2014, 08:59
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It makes sense that more memory capability allowed the 4 digit Cost Index. But why bother? Is 0-999 not an adequate range?
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