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 and handling. The correct choice refers to the power and vertical velocity required to stay on the proper glidepath.

During strong wind shear conditions, pilots may need to adjust engine power significantly to counteract the variations in lift caused by the changing wind. For example, if an aircraft encounters an increase in headwind suddenly followed by a tailwind, the pilot must increase power to maintain altitude and avoid descent below the intended glidepath. Conversely, if the wind shifts from tailwind to headwind, the pilot may need to reduce power. This requirement for constant adjustments to maintain the correct glide path is a direct indication of wind shear.

The other options do not specifically point to wind shear. Changes in heading to remain on the runway centerline might be a factor in strong winds but are more indicative of crosswinds rather than shear. The amount of trim needed pertains more to the aircraft's stability and control forces rather than wind shear specifically. Changes in altimeter readings could indicate altitude changes but are not a direct measure of wind shear effects.