Incorrect calculations after passing TOC
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I flew in South America the past days. I had ISA up to plus 10°C. This obviously leads to a slow climb performance. I entered the ISA DEV in the PERF INIT page, but the calculated TOC was still way too optimistic.
I noticed after passing the calculated TOC and while still in climb, the FMC distance to the TOC increases again. It may go up to the distance all the way to the destination. This will also result in the fuel calculations to become incorrect.
The values are plausible again once reaching the cruise altitude. -
This is expected behavior as the TOC calculations are essentially the predicated TOC calculated by the data entered in the FMS. Therefore, the TOC point calculations are only re-calculated once something has been executed in the FMS. Note that although these calculations will never be perfectly accurate due to external factors such as temperature and wind, etc, the TOC calculations are something we have logged internally as something to potentially look into improving in the future.
Mark - Just Flight
