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Driver 170
10th Jun 2016, 18:45
My question is about derated thrust from 26k down to 24k for example, i have provided two links, first link is a picture of TO 26k

https://www.dropbox.com/s/66d0fm3dfkjx3ix/Photo%2010-06-2016%2C%2011%2042%2059.jpg?dl=0

Second picture is 24k rated thrust TO1, selected in the FMC N1 limit page

https://www.dropbox.com/s/gzggfkjymp4v3ox/Photo%2010-06-2016%2C%2011%2043%2034.jpg?dl=0

You can see on the picture you have an amber marker at the 26k N1 reference bug Green marker.

If i select 24k, is my engine only able to produce 24k of thrust i believe this is true so why does the amber marker stay at same position for 26k? Wouldn't the amber not change and reflect the new derate rating of 24k as this is more limiting and thrust levers shouldn't be advanced beyond the N1 reference green bug.

Also in the FCOM VOL 2; Engines, APU - you have an option without double derate and with double derate. If the operator chooses without double derate the amber band no longer is displayed why is this?

de facto
11th Jun 2016, 21:41
Hi Driver,
If you select 24 k, 26 k is still available even though 24k is considered a limit for single engine vmca issue.
The amber is an option and will show max thrust N1(i.e. 26 k for actual ambient conditions/calculated by the EEC).
If you don't derate then obviously the 26 k limit is shown with the standard N1 (green) bugs.

Driver 170
12th Jun 2016, 14:06
So the amber band doesn't mean MCT then? But apart from that i've got it!

Thanks.

de facto
14th Jun 2016, 13:18
It does when you select MCT via your N1 limit page.