Chances are the pilot was not getting dependable glide slope data.

飞行员错过了设定可靠的下滑道数据的大好机会.

ILS guidance indication is changed to 2 circles that must be inside each other to be on the glide slope and localizer.

着陆导航系统引导指示改成2个圆圈，它们必须重合才满足下滑道和方向定位的要求。