What is an indicator of a strong wind shear during landing?

A strong wind shear during landing is characterized by sudden changes in wind speed and direction, which can significantly affect an aircraft's performance. The correct indication of this phenomenon is the power and vertical velocity required to maintain the proper glide path during the approach and landing phases.

When an aircraft experiences wind shear, it may require sudden adjustments in power and pitch to counteract the changes in airflow over the wings. For instance, if the wind suddenly shifts from headwind to tailwind, the aircraft may lose lift or gain it unexpectedly, creating the necessity for a pilot to apply more power or adjust the vertical rate of descent to stay aligned with the glide path. This adjustment reflects the direct impact of wind shear on the aircraft's performance.

The other indicators, while they may reveal some related flying challenges, do not provide as direct a correlation to wind shear as the need for adjusting power and vertical velocity. For example, changes in heading or trim adjustments may indicate other aerodynamic issues but are not specific signals of wind shear, and fluctuations in altimeter readings can occur due to various factors, making them less reliable for confirming the presence of wind shear.