Which of the following is NOT a critical phase of flight?

The critical phases of flight typically refer to those segments where the risk of accidents is higher and where careful attention by the flight crew is paramount. These phases are characterized by significant operational challenges and require specific focus for safety.

The climb, cruise, descent, and landing phases are all considered critical due to the increased demands on pilot performance and aircraft control. During takeoff and landing, for example, the aircraft operates close to the ground and is subject to rapid changes in performance and environmental conditions. Similarly, during descent, pilots must manage airspeed control and approach stabilization for a safe landing.

Taxiing, while important for overall operations, generally involves lower risk since it occurs at slower speeds and under more controlled conditions on the ground. It is less susceptible to the same types of accidents that can occur during flight phases where aerodynamic performance is critical.

Therefore, the climb and cruise phases are indeed considered critical because they involve significant operational loads, while taxiing, although important, does not represent a critical phase of flight in terms of the heightened risks inherent to flight operations.