Nailing the Needles
[IMGCAP(1)]The first time a pilot on an ILS approach sneaks under the glide-slope is almost always a situation where he is on an ILS final, approaching minimums. Hes close to decision height and suddenly there are patches of ground appearing intermittently below. An instant later, the strobes are visible. He drops below the glide path and the runway is straight ahead. The pilot later realizes that remaining on glide slope at decision height would have meant executing a missed approach and possibly a trip to the alternate airport.
On the next gamble, he descends a little bit more below the glideslope path – and it works again. In fact it may work a number of times. The best estimates i…