Mach tuck the speed of sound and control authority both increase. To prevent Mach stall from progressing, the pilot should keep the airspeed below the type's critical Mach number by reducing throttle, extending speed brakes, and if possible, extending the landing gear. A number of design techniques are used to counter the effects of Mach tuck. On both conventional tailplane and canard foreplane configurations, the horizontal stabiliser may be made large and powerful enough to correct the large trim changes associated with Mach tuck. In place of the conventional elevator control surface, the whole stabiliser may be made moveable or "all-flying", sometimes
Ford Mustang Mach 1 (for use with 4-venturi carbs) versions. The 351C 4V (M code) engine featured 11.0:1 compression and produced at 5400 rpm. This new performance engine incorporated elements learned from the Ford 385 series engine and the Boss 302, particularly the poly-angle combustion chambers with canted valves and the thin-wall casting technology. For 1971, Ford reduced the content of the Mach 1. The standard features of the model were as follows: In 1971, the Mach 1 was available with three 351 Cleveland engines; the H-code 2-V, the M-code 4-V and beginning in May of 1971, the 351CJ (Cobra Jet or GT engine).