Think again Jock
Hi intensity approach lighting should have a minimum of 5 settings
100%
30%
10%
3%
1%
Supplementary approach lighting should have a minimum of 3
100%
30%
10%
It is recommended that LI edge and taxyway lighting have 100% and 30%
Lighting is normally kept at 3% to conserve power and bulbs (apart from PAPIs)
Its a useful demononstration to studes to show how the lights can be turned up as an aid to not only approach recognition but airfield recognition. I can remember having some fun with an FO who lined up at Northolt for an approach to LHR 23- a quick 100% from from LHR soon convinced him to realign his approach!