What is N1?

I have seen in if just above the throttle that there is the ‘N1’ sight I was wondering what this and why when you add a certain amount of throttle the numbers by this sight turn orange?

Thanks in advance 👍🏻

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The rotation speed of the blades in front is N1

N2 is the inner compressor spinning

It is best to use 85-95% N1 for takeoff.


Conceptually, N1 is the fan (or, fan speed ) and is most related to your thrust (since the fan produces more thrust than the core on today’s big motors). The N2 is the engine core, and the N2 gauge is used mainly during engine start.

In infinite flight, The N1% turns orange when it exceeds 100%, which is bad for the engines.

For further clarification, it’s the rotational speed of the front of the compressor. N2 is the rotational speed of the rear of the compressor. These, as you may surmise, are components of a turbine engine.

Generally, you have the intake and compressor, which makes up the cold section of the engine. The combustor, turbine, and exhaust (as well as diffuser if addressed) make up the hot section.


First, the air flows through the intake, then feeds into the compressor. What the compressor does is “squeeze” the air to increase the pressure as much as possible, then it continues into the hot section. There, the combustion component of the engine mixes the air with fuel to create hot gases, continuing on to the turbine. It extracts energy from the hot gases leaving the combustor in a series of bladed discs, usually made of titanium-nickel alloys to withstand the high heat. The exhaust gases from said turbine passes through a nozzle to produce a high-velocity jet, enabling thrust as an end result of the engine’s work.

Those are the rough basics of how it works in a nutshell.


Or to simply it even further:

Suck, Squeeze, Bang, Blow.


Joshua just likes to consistently over complicate things.


You say that now, but one of us will be writing manuals with this diction in the future and it won’t be you. :P


Nor you since it’s been written now for 40+ years. Don’t act like you are learning anything in this so called “School”

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And so the dance continues. I do enjoy those conversations. ;)

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