Which type of aircraft is most at risk when landing in a 25-knot crosswind?

The correct choice is general aviation, single propeller aircraft because these types of aircraft are typically lighter and have a lower aerodynamic stability compared to larger commercial jets and military fighters. Single-propeller aircraft often have a higher sensitivity to wind conditions, particularly crosswinds.

During landing, these aircraft rely significantly on their control surfaces to maintain stability and alignment with the runway. In a 25-knot crosswind, the risk of losing control increases, leading to the possibility of a crosswind landing accident. This issue is exacerbated during low-speed operations, such as final approach and touchdown.

In contrast, commercial jets and military fighters are designed with advanced control surfaces and systems that can better manage high wind conditions. Helicopters also have unique capabilities such as the ability to hover and adjust their landing approach, which reduces their exposure to crosswinds compared to fixed-wing aircraft. Thus, the general aviation, single propeller aircraft is indeed the most at risk in such landing scenarios.