What outcome occurs when an aircraft is affected by headwind to tailwind shear during approach?

When an aircraft experiences headwind to tailwind shear during approach, it generally results in the aircraft dropping below the glideslope. Headwind to tailwind shear means that as the aircraft descends, it transitions from flying into a headwind (which helps to maintain lift and slows the aircraft down) to a tailwind (which can increase its groundspeed). This shift can cause the aircraft's descent rate to change unexpectedly, leading to a loss of altitude control.

In practice, when the aircraft enters a tailwind condition, it may not descend as expected or might inadvertently descend more steeply than planned, causing it to drop below the ideal glide path. This situation can pose challenges for pilots, as they must react quickly to adjust their approach to maintain the correct descent profile toward the runway. Understanding this phenomenon is crucial for effective approach management and ensuring safe landings, particularly in variable wind conditions.