What is the purpose of a displaced threshold on a runway?

A displaced threshold is a section of runway that is available for takeoff but not for landing. The primary purpose of a displaced threshold is to create an effective landing area that ensures aircraft will touch down at a safe distance from obstacles or other hazards located near the beginning of the runway. By design, this threshold is positioned further down the runway, thus preventing aircraft from landing too close to the start of the runway.

This allows for a safer approach and landing phase, where pilots are able to avoid potential obstructions while also providing them with adequate distance to bring the aircraft to a stop without risking a runway overrun. Essentially, it improves the safety and effectiveness of landings by designating the appropriate point for touch down, which is attained through placement of the threshold itself.

The correct answer highlights that the displaced threshold influences the landing dynamics by requiring aircraft to touch down farther down the runway, ensuring they land safely and efficiently.