What is the purpose of a gust lock in an aircraft?

The role of a gust lock is to act as a latch mechanism that secures an aircraft door in either the open or locked position, preventing it from inadvertently closing or opening during critical phases, such as boarding or deplaning. This safety feature is essential for ensuring the safety of passengers and crew by maintaining the integrity of the aircraft structure and preventing accidents or injuries caused by mishandling of the doors in gusty wind conditions. The proper functioning of a gust lock is vital to the overall safety protocols in aviation, as it mitigates risks associated with strong winds impacting door operations.

In the context of the other provided choices, securing doors during flight or controlling cabin pressure does not accurately describe the function of a gust lock, nor does a device to measure wind speed. Each of these other functions pertains to different systems or components within an aircraft's operational framework, highlighting the specific and vital role of a gust lock in door management.