Which of the following factors does NOT contribute to Mach tuck?

Mach tuck refers to the aerodynamic phenomenon where an aircraft experiences a nose-down pitching moment at high speeds as it approaches transonic speeds, typically beyond a Mach number of 0.8. This behavior is primarily influenced by changes in airflow and pressure distribution over the wings and fuselage as speed increases.

Increased airspeed is a direct contributor to Mach tuck because as an aircraft accelerates, the pressure differential across the wings changes, leading to changes in lift and drag characteristics. Similarly, a high angle of attack, especially at high speeds, can exacerbate this effect because it can lead to airflow separation and altered pressure distribution around the wing. Additionally, stall characteristics play a role in Mach tuck, as an aircraft nearing stall conditions can experience abrupt changes in lift and control effectiveness, further contributing to the phenomenon.

Conversely, low altitude does not significantly contribute to Mach tuck. At lower altitudes, the altitude does not directly impact the aerodynamic effects associated with increased Mach numbers. While lower altitude can increase air density and affect overall performance, it is the speed and angle of attack that primarily drive the Mach tuck behavior. Therefore, low altitude is correctly identified as not being a contributing factor to Mach tuck.