Clean Configuration

Clean configuration refers to an aircraft state where all high-lift devices (flaps and slats) are fully retracted and the landing gear is up. This is the normal configuration for cruise flight, offering minimum aerodynamic drag and maximum fuel efficiency.

In clean configuration, the aircraft's stall speed is at its highest because the wing is not augmented by extended flaps or slats. This means that approach and maneuvering speeds must be significantly higher than in landing configuration. The transition from clean to landing configuration (and vice versa) must be managed carefully, with speed adjustments coordinated with each stage of flap/slat extension or retraction.