What is the primary function of landing gear doors when the gear is retracted?

The primary function of landing gear doors when the gear is retracted is to seal the wheel-well and create an aerodynamic surface. This aerodynamic design helps to minimize air resistance and drag as the aircraft moves through the air, contributing to overall flight efficiency. By effectively enclosing the landing gear space, these doors reduce turbulent airflow that could negatively impact aerodynamic performance.

Additionally, the landing gear doors play a crucial role in protecting the internal mechanisms of the landing gear from debris, moisture, and other environmental factors while also streamlining the aircraft's profile. This function directly correlates with maintaining optimal performance and enhancing fuel efficiency during flight.