Mach tuck refers to a nose-down pitch tendency that occurs when an aircraft accelerates beyond its limiting Mach number during transonic flight. As the aircraft speeds up, the wings generate more lift. To maintain level flight, a nose-down trim is necessary. In this phase, the shock wave forming on the wings shifts backward and intensifies. This shift leads to a rearward movement of the center of pressure, causing the nose-down or “tucking” tendency known as Mach tuck. If the aircraft continues to accelerate past the limiting Mach number, the center of pressure may move so far back that there isn’t enough elevator authority to counteract the nose-down moment. This situation can result in a steep, potentially unrecoverable dive.
