At what height AGL should i be when i am about 5NM from the runway? Or approximately when those red landing aid squares start? I am not using them and i try to follow the glide-slope but i never know at what height i should intercept the ILS.
Totally depends on the elevation of the airfield…but all I can say is try to find a constant rate of descent that you feel comfortable with that will guide you to the ground a couple of seconds after crossing the runway threshold :)
The altitude varies on the airfield a good way to figure it out is using the glidescope, this will tell you exactly what altitude is ideal but obviously other factors play a part.
Your rate of descent or -Vs is the key to a steady descent, again have a play around and find what suits you best, I find -800vs works fine for me at around 180knts and then reduce that as I get closer.
Jump in an aircraft with an APPR feature and whilst it’s landing for you keep an eye on everything and then make your own decision :)
Almost all glideslopes follow a 3 degree angle. This means that for every one mile you are from the threshold, you need 300 ft. For instance, at 5 miles, you should be at 1500 ft. 300x5=1500. You can see your distance using the DME in the HUD. You should intercept the localizer below the glideslope, so 2500 feet is a good altitude. After intercepting the localizer fly runway heading at a level altitude, until the glideslope comes alive and meets the center. At that point just fly the ILS. Hope that helped :)
I usually intercept the localizer at about 2500ft or whatever approach tells me to intercept at. Once I do intercept I set my vertical speed to about -800 and then I disconnect the AP at about 1000ft or whenever I’m comfortable. If everything goes right and you follow your instruments you should cross the threshold at 50ft.