Final answer:
Mach tuck is caused by the rearward shift of the center of pressure on an aircraft's wings as it approaches the speed of sound, resulting in a nose-downward pitch. This aerodynamic behavior can impact aircraft control, requiring pilots to use nose-up trim or automatic Mach trim systems to maintain stability.
Step-by-step explanation:
The cause of high-speed tuck under, known as Mach tuck, is a phenomenon that occurs at high speeds when an aircraft approaches or exceeds the speed of sound (Mach 1). As the aircraft gets faster, the center of pressure moves rearward due to the change in the distribution of shock waves over the wings. This shift in the center of pressure causes a downward force on the tail, making the nose of the aircraft pitch downward. This condition can deteriorate aircraft control and is inherently dangerous if not managed properly.
The impact of Mach tuck increases progressively with speed because as the Mach number increases, the air over the wing becomes more supersonic, intensifying the rearward movement of the center of pressure and exacerbating the tuck under effect.
To combat Mach tuck, pilots may be required to apply nose-up trim or the aircraft may be equipped with systems such as Mach trim systems, which automatically adjust the horizontal stabilizer to counteract the tendency of the nose to pitch downward.