Originally Posted by
compressor stall
Have a think about the MEHT for your aircraft route and that of the runway.
There’s more potential variability there than anything you’ve suggested.
What I'm trying to deduce here (which was not clear in my initial post) is whether there is any rule of thumb based on my aircraft GS (consider a medium wake aircraft) to calculate at what distance or time on a normal 3-degree glideslope, will I see a change in lights i.e. from the lights going from 2RED 2 WHITES to 3 RED or 3 whites, if the glide was not maintained.
Also, Considering the Glidepath of the PAPI and ILS glideslope exactly matched, will I see the change at half dot deviation of the Glide slope indicator, or since the PAPI is a visual reference it would require a little more time to show or perceive the change?