How to Secure your Airport Slots

Because demand exceeds supply at major international airports, due to limited runway, terminal, and airspace capacity, many of them implement regulatory measures to organize and manage traffic efficiently.

These measures often include:

• Restricting certain airports to scheduled commercial airlines, while designating others for charter and general aviation.
• Imposing higher fees at busy airports and offering discounts at regional ones.
• Assigning specific arrival and departure times. These time restrictions are known as airport slots, and airports that enforce them are referred to as slot-coordinated airports.

In this guide, we highlight the main aspects of airport slots from a business aviation perspective, as commercial airlines are subject to a more detailed regulatory framework.

 

Who Allocates Slots?

Slots are required for both arrival and departure, meaning two separate time slots must be secured for each flight.

While the Civil Aviation Authority (CAA) issues landing permits, it is not responsible for airport slots. Some airports manage their own slot allocation, while others delegate this function to specialized governmental or private entities known as Slot Coordinators.

These coordinators process and approve slot requests by analysing traffic demand and coordinating with airport authorities regarding aircraft parking and ground handling availability.

Will You Get the Time You Want when Requesting an Airport Slot?

At congested airports, especially during peak hours getting your desired slot time can be challenging. If your requested slot is unavailable, the slot coordinator will reject the request and suggest the nearest available alternatives.

Slots are generally issued on a first-come, first-served basis, with priority often given to:

• Scheduled commercial flights
• Government flights
• Air ambulance services

In some airports, business aviation slots are only available outside peak hours, which are reserved for commercial airline operations.

 

How to Apply for Airport Slot?

Aircraft operators can usually apply for slots directly. However, procedures vary by airport:

• Some airports require prior registration for slot applications (e.g., HKG).
• At others, only the FBO is authorized to apply (e.g., DXB, BRU).
• While many airports now have online portals, others still accept applications via SITA messages or email.

 

Standard Slot Request Formats

The two most common formats are:

• Slot Clearance Request (SCR) – Uses IATA airport codes.
• General Aviation Clearance Request (GCR) – Uses ICAO airport codes.

Slot requests must include the following details:

• Aircraft type
• Registration
• Callsign
• Arrival and departure times
• Date of operation
• Origin and destination

Responses will confirm approval, suggest alternate times, or reject due to formatting issues. Some airports issue a slot number that must be entered in Field 18 of the flight plan (e.g., BRU).

 

When to Apply for an Airport Slot

At many airports, securing an approved slot is a pre-condition for obtaining a landing permit. It’s recommended to apply well in advance, though short-notice applications are sometimes possible.

Be aware that not all slot coordination offices operate 24/7. Applications submitted outside working hours may be delayed.

 

Slot Validity and Deviation

Unlike landing permits, which may be valid for 24–72 hours depending on the country, slot validity is typically much shorter.

What is a Slot Deviation?

Slot deviation refers to the acceptable time window within which an aircraft can arrive or depart relative to the approved slot. This can vary significantly:

• Strict airports: ±10 to 20 minutes
• Flexible airports: ±1 to 2 hours

Consequences of Non-Compliance

Operating without an approved slot or deviating from assigned times can result in:

• Flight plan rejection
• Fines and penalties
• Low priority for future slot requests
• Freezing of the operator’s slot account
• In severe cases, suspension or bans from the airport
• Legal action or imprisonment (in rare cases)

Additionally, failing to cancel unused slots may result in penalties, as this blocks other operators from accessing those times.

 

Types of Slot Coordination Levels

Clarify that not all airports are fully slot-coordinated. Airports typically fall into 3 categories:

• Level 1 (Non-Coordinated): No slot coordination required; there’s enough capacity.
• Level 2 (Schedule Facilitated): Some monitoring is done, and operators should advise intentions, but it’s not strictly regulated.
• Level 3 (Fully Slot-Coordinated): Slots are mandatory and strictly regulated.

 

Difference Between Airport Slots and ATC Slots

A common point of confusion is between:

• Airport Slot: Assigned by airport authorities for ground capacity (gates, runways, etc.)
• ATC Slot (CTOT – Calculated Take-Off Time): Assigned by Air Traffic Control (like Eurocontrol in Europe) to manage airspace congestion.

 

Slot Monitoring & Usage Rules

Some airports and coordination bodies monitor slot usage rigorously. If operators don’t use a certain percentage of the slots they’ve been allocated, they may lose them in future.

• This is part of the “use-it-or-lose-it” rule (e.g., 80/20 rule in IATA Worldwide Slot Guidelines – WSG).
• Particularly applies to seasonal slots at Level 3 airports.

 

Real-Life Examples or Case Studies

Briefly referencing a few notable airports with strict slot procedures could add practical value:

• Heathrow (LHR): One of the most slot-constrained airports in the world.
• Hong Kong (HKG): Requires prior registration, strict deviation limits.
• Teterboro (TEB): High demand for business jets, noise restrictions, and curfews.
• Tokyo Haneda (HND): Very limited access for GA, complex approval process.

 

Slot Trading / Secondary Slot Markets

Mainly for commercial airlines, but worth a mention:

• At some congested airports, slots have significant commercial value and may be bought, sold, or traded on secondary markets.
• Though not typically available to GA or business aviation, it highlights how valuable slots can be.

 

Resources and Tools you may use for slots arrangements

• IATA Worldwide Slot Guidelines (WSG)
• Local slot coordinators’ websites (e.g., Airport Coordination Limited for the UK)
• Eurocontrol’s NOP portal (for ATC slots)

 

Secure Your Airport Slots on Short-notice

As demand for air travel continues to rise, more airports are adopting slot coordination. This is particularly true in airports constrained by limited space, curfews, or strict expansion regulations.

Given the complexity and variation of slot rules across airports, partnering with a professional flight support and trip planning service is often essential to secure the necessary slots, especially at high-demand locations.

 

Frequently Asked Questions for Airport Slots (FAQ)

1. Do slot requests incur a cost or fee?
   In many jurisdictions, there is either an administrative processing fee for slot requests or a handling charge from the slot coordinator. The fee may vary depending on whether the slot is for scheduled, charter, or general aviation. The fee is separate from landing, parking, or handling charges.
2. Can I transfer, swap or trade a slot with another operator?
   In some coordinated systems, slot swaps or transfers are allowed under strict oversight. But any such transaction typically requires approval from the slot coordinator (or relevant authority). The swap must comply with rules in the jurisdiction or the applicable slot guidelines (for example under IATA’s WASG conditions).
3. What happens during disruptions (weather, technical, emergencies)?
   If a flight cannot use the allocated slot due to unforeseen disruptions (e.g. weather, mechanical failure), many slot coordinators treat these as force majeure cases. Operators may be excused from penalties and might be allowed to re-book or defer the slot. But this is handled on a case-by-case basis, and documentation may be required.
4. Are there exemptions to slot requirements (e.g. for medical, emergency, government flights)?
   Yes, some airports exempt certain flight types from slot rules — for example, medevac, humanitarian, or military/government flights in certain situations. The exact exemptions depend on the airport and local regulations. Always check with the slot coordinator or airport prior to flight.
5. What is “historic precedence” (or “historic rights”) and how does it work?
   At many coordinated airports, operators that have consistently used a slot in a previous season may be given priority for the same slot in the next season. This is sometimes referred to as “historic rights.” However, this privilege is conditional on meeting utilization thresholds and compliance requirements. If an operator under‑uses or misuses the slot, they may lose their historic claim.
6. What is “slot monitoring” or “slot performance measurement”?
   To ensure slots are used properly, coordinators may monitor actual operations versus the allocated slot (arrival/departure times, cancellations, deviations). Operators who consistently misuse or deviate may receive warnings, face slot suspension, or lose priority. Monitoring ensures the system remains fair and efficient.
7. Can I apply for a slot on very short notice, even the same day?
   In some airports, ad hoc or last-minute slot requests are possible (if capacity allows). But this is risky and not guaranteed, especially at highly congested airports. Many coordinated airports limit short-notice allocations, or may only grant slots outside peak hours.
8. How far in advance do slot coordinators publish the coordination calendar or deadlines?
   Slot coordinators (especially in regulated markets) typically publish a calendar of coordination activities in advance, including key deadlines for submitting slot requests, for slot exchanges, or for cancellations. These calendars are often aligned with the seasonal scheduling periods (e.g. summer/winter).
9. Do slot rules differ between seasons (summer vs winter schedule)?
   Yes. Most slot‑coordinated airports operate on seasonal scheduling cycles (e.g. Summer and Winter schedules). Slots are allocated for each season, and operators may need to reapply or confirm slots when switching seasons.
10. What recourse do I have if my slot request is unfairly denied?
    Many slot coordination systems have an appeals process, or a mechanism to escalate disputes. Operators may file appeals with the slot coordinator, oversight bodies, or regulatory authorities. It’s important to document the request and rationale.
11. Can an operator hold too many slots and “hoard” capacity?
    Yes, hoarding is a concern. Many slot regimes include anti‑hoarding rules or limits: operators must demonstrate consistent usage, or they risk forfeiting unused slots. Some regulators or coordinators actively monitor and penalize hoarding to ensure fair access.
12. Are slot applications handled in local time or UTC / standard time base?
    Most slot coordination systems and communications use UTC (Coordinated Universal Time) to avoid confusion across time zones. Always confirm with the slot coordinator which time standard is used when submitting requests.

 

Sources:

1. https://www.iata.org/en/programs/ops-infra/slots/slot-guidelines
2. https://www.iata.org/en/programs/ops-infra/slots
   https://www.gov.br/anac/en/topics/air-services/slot-coordination
3. https://www.ecologie.gouv.fr/en/public-policies/slot-coordination-schedules-facilitation
4. https://www.cohor.org/