Business Aircraft Operations in the UK: Airport Slots

PT 3 M minute read
Business Aircraft Operations in the UK: Airport Slots

This is a post by author Jason Hayward. Jason is general manager for Universal Aviation U.K. – London-Stansted. Jason is an expert on business aircraft operations in the U.K. and can be contacted at

This business aviation blog post is part of a series on operating in the UK and continues from our last article: “Business Aircraft Operations in the UK: Customs, Immigration, and Quarantine

When airport slots are required for UK destinations, best practice is to submit requests as early as possible. Business aircraft operators will need to request airport slots via a 3rd-party provider or ground handler rather than directly, unless you have a direct account with the Airport Coordination Limited (ACL) slot system.

The following is an overview of what you need to know:

1. Are airport slots required for UK?

Airport slots are needed for most airports in the London area – Stansted (EGSS), Luton (EGGW), Heathrow (EGLL), London City (EGLC), and Gatwick (EGKK). Outside the London area, airport slot requirements are rare. Slot requirements are in place to manage airport traffic flow and airport ground capacity.

2. How are airport slots requested?

Airport slots must be requested through the Online Coordination System (OCS) website (part of ACL) and not via local airport authorities. OCS shows live slot availability for many different airports at any given time. To request and obtain airport slots, you need to know expected on and off block times, departure point, tail number, aircraft type, and seating capacity. To request slots, you must have an ACL account or use a provider, such as your ground handler, with an account. ACL has exclusive responsibility for allocation of airport slots at major UK airports.

3. What’s the slot allocation process?

OCS uses three colors to indicate slot availability. Amber indicates that slots may be available, red means no slots are currently available, and green signifies airport slot availability. Each airport requiring slots has a certain number available for each time period. For example, at EGSS there are a certain number of slots available per hour, with slot availability broken down into five-minute periods. EGSS slot deviation is -10 minutes/+15 minutes for arrival and -10 minutes/+20 minutes for departure, and these are all “off block” times.

4. When can airport slots be requested?

Airport slots may be requested months in advance for either the summer season (April through October) or the winter season (November through March). Depending on the airport, you may or may not be able to obtain short-notice slots. EGLL, for example, is almost always operating at capacity. EGKK also has limited slots due to high activity for scheduled commercial aircraft. Commercial carriers are given slot priority, and many of them plan schedules and request slots, months in advance. At other UK airports, there’s usually plenty of slot availability.

5. What are some other slot tips?

Each airport slot has a number with an associated slot code. If an airport slot time is going to be missed, you’ll need to update the slot to reflect the new operating time (same slot number and code but a new time). The slot code should be inserted into field 18 of your flight plan. If departure delays are anticipated, ensure that your ground handler updates the airport slot. It’s also important that airport slots always match departure airway slots.

6. Additional reading: “Business Aircraft Operations in the UK” series index

Links will be added as new articles are published.


As soon as schedule is known, have your ground handler request and confirm any required airport slots. ACL does not charge per slot issued, but they do charge an annual fee for OCS site access. Be aware that most ground handlers charge fees for arranging UK airport slots.


If you have any questions about this article or would like assistance planning your next trip to the UK, contact me at

Later, we’ll discuss landing permits and prior permissions required for the UK and their impact on your trip.

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