During what phases of flight is the maximum weight limit particularly critical?

The maximum weight limit is particularly critical during takeoff and landing because these phases of flight involve significant aerodynamic and structural considerations. During takeoff, exceeding the maximum weight can prevent the aircraft from achieving the necessary lift required to become airborne, leading to safety hazards, such as a longer takeoff roll, difficulty in reaching the required takeoff speed, or even the inability to take off at all.

Similarly, during landing, weight is crucial for controlling the descent rate and managing landing speeds. An aircraft that is too heavy may struggle to stop effectively, which can increase landing distances, lead to potential overruns, or cause gear or structural failures upon touchdown due to excessive forces.

These requirements make managing weight during takeoff and landing essential for safe aircraft operation, as they directly impact the aircraft's performance and safety margins. The other phases, such as climb, descent, cruise, taxi, and taxiway operations, while they do have weight considerations, do not present the same critical scenarios for performance and safety as takeoff and landing do.