When should you begin your descent from a straight-in approach with flaps landing?

Beginning your descent from a straight-in approach with flaps landing should occur when the threshold is in the lower one-third of the windscreen. This guideline helps pilots establish a good visual reference to ensure that they are properly aligned and at the correct altitude for the approach.

When the threshold is visible in the lower one-third of the windscreen, it serves as a cue that the aircraft is at an appropriate altitude and position for a stable approach. This optimal sight picture indicates that the pilot can initiate a descent while still maintaining control and ensuring that they are on the correct glideslope to land successfully.

Recognizing the visual cues provided by the windscreen allows for better situational awareness and helps pilots avoid being too high or too low on approach. Proper timing of the descent is critical for achieving a successful landing, as it allows for adequate distance to manage speed, configuration, and descent rate, leading to a safe touchdown.