Maybe we were too simplistic back in 1987
Long. long time ago....Sillly Bims and I, along with some flight ops and flight safety folk (a joint civil/RAAF team under the Air Coordinating Committee) looked at the "rules" for commencing an instrument approach. At the time RAAF aircraft could commence one but civil aircraft could not if the reported vis was below the minima. Mainly at Canberra, but it happened elsewhere, the accusation was that RAAF aircraft were "busting the minima".
Based on trust in the professional approach of pilots and after much discussion we decided that, having executed a prescribed instrument approach to place the aircraft on final near the runway and approaching the minimas the pilot was in the best position to look ahead and, if he/she, had the "runway environment" in sight decide to go ahead and land. We thought that controllers and met folk who were possibly several kilometers away and looking the "wrong" way and without the benefit of approach and runway lighting systems designed specifically to make the runway visible in low vis conditions were not the best placed to make operational landing decisions. As a result, AOI's etc were changed.
So, you have executed a prescribed instrument approach, you are approaching or at (but certainly not below!) the minima and you look ahead and see the "runway environment" surely you can go ahead and land. No need for maths formulas, slide rules, special equipment or worry.
Standing by for incoming.
MJG
Last edited by mgahan; 18th Feb 2016 at 14:16.