Airport Slot Coordination

Airport Slot Coordination is the formal system used at congested airports to manage runway and terminal capacity by allocating specific time windows for arrivals and departures.

Under IATA's Worldwide Slot Guidelines (WSG), airports are classified as Level 1 (non-coordinated), Level 2 (schedules facilitated), or Level 3 (fully coordinated). At Level 3 airports, airlines must hold a confirmed slot to operate.

• Governed by the 'use-it-or-lose-it' 80/20 rule (airlines must use 80% of their slots to retain them)
• Slot pairs (arrival + departure) are allocated by independent coordinators
• Historic precedence (grandfather rights) gives priority to incumbent airlines
• Slot trading is common at congested hubs like Heathrow and JFK