Genista Posted January 21 Share Posted January 21 Firstly, I apologize for re-opening this topic, but the initial thread got closed with my claim dismissed without leaving me the opportunity to clarify so, here we are. Initial post: What I would like to add following Nico's feedback: 1/ Regarding initial post My report concerns in-flight/hi power settings behavior (climb/cruise), I agree that on ground the impact is visible. See below screeshots, notice how the N1/N2/EGT... remain identical. 2/ Regarding N1 effect on ground: - I need to check more papers on the CF6 version - but on the PW, you have a modulating idle concept where the idle setting increases to match the bleed pressure demand. Bleed pressure demand increases with air conditioning load, and anti-ice systems. See FCOM Chap. 1.17.20 - In case the N1 remains the same, you should still see a change in EGT, FF and N2 (because you are taking power from the engine). 3/ Regarding in-flight effects - FCOM Chap. 1.13.30 mentions (on PW at least) a decrease of Thrust Limit relative to bleed load. - For the same reasons stated above and in original thread, increasing bleed load (by the use of anti-ice, or running both packs from the same engine etc) should have a visible impact on EGT/N2/FF/N1. You are taking power from the engine, the power you take is power that won't be used to spin the turbines. Your efficiency decreases, at a given fuel flow, you will have a lower N1 and higher EGT. And a lower N1 will reduce your thrust (and therefore impact climb rate). Note: Only FCOM references are posted in order not to post copyrighted material publicly, more details can be provided by PM. Hopefully it is clearer this time. Cheers, 1 Link to comment Share on other sites More sharing options...
Deleted Account Posted January 22 Share Posted January 22 No need to apologize at all! Thanks, will take this into consideration as well 🙂 1 Link to comment Share on other sites More sharing options...
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