Hi Blade,
It has been a few years since I last worked on the B737, I seem to remember that the low Idle light illuminates under the followinging conditions.
* Inflight
* Eng A/I on
* Any Eng N1 less than 45%
The reason behind this light (It was an Airwothiness Directive) was a series of flameouts early on in the CFM56-3īs service life. This AD also dictated shortening the HP/LP splitter lib in the engine, as well as replacing the conical shaped spinner with a bullit shaped one.
So If I had been your freindly groung engineer this morning, and if i had no spares to do it with(I wouldnīt have
) I would have adviced you to monitor your engine parameters closely in icing condition, and adviced you to keep your N1 above 45% at all time.
Brgds
Doc