Airport slots

A ‘slot’ is the permission given by an airport ‘coordinator’ for an aircraft to arrive or depart at a specific airport at a specified time on a specified day. This permission allows an aircraft, along with its crew and any passengers, access to the airport infrastructure, including runway, terminal facilities, baggage handling and operational requirements such as aircraft refuelling.

Slots are used by busier airports all over the world to make the most efficient use of their capacity, giving greater control of when flights arrive and depart, providing transparency to airlines and other aircraft operators, and minimising congestion and delays.

Slots don’t change any of Bristol Airport’s existing restrictions – whether on noise, night flights, air traffic movements cap, or our passenger cap. They do, however, provide the Airport with an important mechanism to manage our operating restrictions.

Airport coordination is a means of managing airport capacity through the application of rules and regulations set out by the EU and the International Air Transport Association (IATA). Coordination involves the allocation of constrained or limited airport capacity to airlines and other aircraft operators to ensure a viable airport and air transport operation.

The process of slot allocation is designed to achieve the maximum utilisation of scarce airport capacity within an acceptable level of delay.

If an airport is designated as Level 3 coordinated, it enables the control of slot allocation along with the monitoring of slot usage to ensure carriers adhere to the given slot.

For the purposes of airport coordination, airports are categorized by the responsible authorities (the Department for Transport in the UK) according to the following levels of congestion:

Level 1: airports where the capacity of the airport infrastructure is generally adequate to meet the demands of airport users at all times.

Level 2: airports where there is potential for congestion during some periods of the day, week, or season, which can be resolved by schedule adjustments mutually agreed between the airlines and facilitator. A facilitator is appointed to organise the planned operations of airlines using or planning to use the airport.

Level 3: airports where demand for airport infrastructure significantly exceeds the airport’s capacity during the relevant period, or where governments have imposed conditions that make it impossible to meet demand. A coordinator is appointed to allocate slots to airlines and other aircraft operators using or planning to use the airport as a means of managing the declared capacity.

Bristol Airport began operating as a Level 3 fully coordinated airport in 2024, with slots 24 hours a day throughout the year. Permission to do this was granted by the Department for Transport.

Bristol Airport currently uses Airport Coordination Limited (ACL) as its appointed facilitator (also known as a 'Coordinator').