ILS - instrument landing system
As you probably know.. The lights, usually 3, each a different colour, are activated by vertical radio beams placed in the landing path at certain intervals. I don't think the distances were standardised at that time, but they just gave the pilot an indication of how far he was from the runway. As the beams are vertical you pass through them very quickly causing the lights to flash briefly. If you keep the needles in the middle (on the dot) you should 'hit' the runway a couple of meters in.
As you hit the last beacon, you should seriously consider flaring and hold it there until your wheels hit something
