A320 NEO CFM oddities
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A320 NEO CFM, N1 split during manual thrust
Hi,
I have been flying the airbus for some time now and during the past year almost exclusively the NEO with CFM engines and I have noticed the following things and I am wondering if someone is able to explain it a bit.
I fly manual thrust in 9/10 cases.
During taxi and airborne there is a gap between the physical Idle stop and until the engines are actually spooling up, I am have not measured the angle but it feels like its maybe 2-3 degrees.
It also occurs quite often that the engines spools up differently and are being kept at split N1 with equal amounts of lever angle on low power settings on approach and taxi.
This is especially prevalent during these times of low gross weights and Flap 3 landing settings.
Another consequence of this "idle gap" is that speed control is much more difficult since low thrust settings are required on a standard 3 degree path compared to CEOs (IAE engines).
I never saw split N1/EPRs on the CEO.
What is going on here?
Edit: On higher thrust settings the N1 split disappears.
I have been flying the airbus for some time now and during the past year almost exclusively the NEO with CFM engines and I have noticed the following things and I am wondering if someone is able to explain it a bit.
I fly manual thrust in 9/10 cases.
During taxi and airborne there is a gap between the physical Idle stop and until the engines are actually spooling up, I am have not measured the angle but it feels like its maybe 2-3 degrees.
It also occurs quite often that the engines spools up differently and are being kept at split N1 with equal amounts of lever angle on low power settings on approach and taxi.
This is especially prevalent during these times of low gross weights and Flap 3 landing settings.
Another consequence of this "idle gap" is that speed control is much more difficult since low thrust settings are required on a standard 3 degree path compared to CEOs (IAE engines).
I never saw split N1/EPRs on the CEO.
What is going on here?
Edit: On higher thrust settings the N1 split disappears.
Last edited by dcoded; 4th November 2020 at 09:54.
