Please update your Flash Player to view content.

Online Coordination

Slot Performance Monitoring





1.      Purpose of slot monitoring

Pursuant to EU Reg 95/93, Art 4, par 6, the Schedule Facilitator shall monitor the conformity of the air carriers' operations with the schedules recommended to them and the Coordinator shall monitor the conformity of air carriers' operations with the slots allocated to them. According to WSG 8.9.2, the coordinator’s monitoring function is established in order to ensure adherence to allocated slot times within normal operating tolerances.

Airlines must not intentionally operate services at a significantly different time or intentionally use slots in a significantly different way than allocated by the Coordinator.

In case of non-compliance, the Coordinator will impose sanctions as described in this document.


2.      Principles of slot monitoring by the Coordinator

 a)   Establish objective, transparent and non-discriminatory criteria

b)    Identify the intentional misuses of slots and off slot operations

c)    Give to the operators the opportunity to proceed to corrective actions

d)    Ensure that monitoring of slots will improve the airport operations


3.      Definitions (in alphabetical order)

Air Carrier: An air transport undertaking holding a valid operating license or equivalent at the latest on 31 January for the following summer season or on 31 August for the following winter season. The definition of Air Carrier shall also include business aviation operators, when they operate according to a schedule; the definition shall also include all civil aircraft operators.

     Beyond its reasonable control:   This could include

  1. Weather conditions
  2. Industrial actions
  3. Air traffic control regulations
  4. Technical issues.

The burden of proof is on the carrier to demonstrate that its failure to comply with the cleared times was beyond its reasonable control.

Coordinator: The organization or individual responsible for slot allocation at a Level 3 airport.

Coordination Parameters: The operational limits of all technical, operational and environmental factors at the airport.

Facilitator: The organization or individual responsible for collecting data on planned operations at a Level 2 airport, and recommending voluntary schedule adjustments as necessary

Intentionally: The carrier intended to land or take-off an aircraft at or about the time that it did land or take off, if this is different from the allocated slot time. A typical example of misuse is when published times are the same with actual block times and differ from allocated slot times.

Landing and take-off : Landing and take-off shall mean the times at which the aircraft arrives at and leaves the terminal ( Block Times).

Repeatedly : More than once in the current IATA scheduling season on a particular scheduled or non-scheduled service operated by an air carrier to or from the airport in question, or more than one ad hoc service in the current IATA scheduling season operated by an air carrier to or from the airport in question.

Significantly different time: Any difference between the intended (planned) landing or take-off time and the allocated slot time which breaches the coordination parameters for the airport will be regarded as a ‘’significantly different  time’’  as it is likely to affect other air carriers.

Significantly different way: Carriers will be considered as operating in significantly different way when

  1. Operating a different aircraft than the aircraft allocated in slot,  or
  2. Operating with false indication of Service Type in the allocated slots that affects airport parameters, or
  3. Operating with an aircraft with significantly more seats than the ones indicated in the allocated slot 
  4. Operating with intentionally false indication of route (eg SCHENGEN -NON SCHENGEN) that affects airport parameters

Slot: Means the permission given by a coordinator to use the full range of airport infrastructure necessary to operate an air service at a coordinated airport on a specific date and time for the purpose of landing and take-off as allocated by the coordinator.

Slot Tolerance: According to HCAA regulation 4 the Slot Tolerance Time at all Greek Coordinated Airports is -/+ 20 minutes both for arriving and departing times.

Slot Tolerance Time (-/+ 20 minutes) should not be confused with the difference between published schedule and allocated slots. Tolerance times are given for operational reasons.


4.      Types of slot misuse

The most common types of misuse are when:

  1. The Carrier operates according to published schedules which are different from the allocated slot times.
  2. The use of a slot in a significantly different way (DIF) from that indicated at the time of allocation, where such use causes prejudice to airport or air traffic operations ( as described in the Definitions of this document)
  3. Operation of a flight without an allocated slot (GOSHOWS) with the   exception of Ambulance, Government, Sanitary and Humanitarian flights and the flights that operate to  recover service (eg AOG)  which they might need to operate with no slot  (when this is not available) in order to avoid passenger inconvenience. These flights are obliged to request a slot from the coordinator in working hours or through OCS or AMP in off working hours. In case there is no slot available, the carrier should have the approval of the airport operator before operating the flight.  
  4. The failure to operate a slot allocated by the coordinator without cancelling it in advance, and thereby causing prejudice to airport or air traffic operations (NOSHOWS) with the exception of flights that fall into the scope of EC 95/93, Article 10, par 4, as follows:

4.1. unforeseeable and unavoidable circumstances outside the air carrier's control leading to:

• grounding of the aircraft type generally used for the air service in question;

• closure of an airport or airspace;

• serious disturbance of operations at the airports concerned, including those   series of slots at other Community airports related to routes which have been affected by such disturbance, during a substantial part of the relevant scheduling period;

4.2. interruption of air services due to action intended to affect these services which makes it practically and/or technically impossible for the air carrier to carry out operations as planned;

4.3. serious financial damage for a Community air carrier concerned, with, as a result, the granting of a temporary license by the licensing authorities pending financial reorganization of the air carrier in accordance with Article 5(5) of Regulation (EEC) No 2407/92;

4.4. judicial proceedings concerning the application of Article 9 for routes where public service obligations have been imposed according to Article 4 of Regulation (EEC) No 2408/92 resulting in the temporary suspension of the operation of such routes


Explanatory Notes

  •  Each of the above types of misuse must be repeated and intentional before the carrier will be liable for possible sanctions. The carrier should be ready to provide records to the Coordinator if the slots fall into the exceptions of the above types of misuses.
  • In any case, proven misuse will be counted against the 80-20 rule as regards historic eligibility.
  • There may be other forms of slot misuse which become identified over time, and which may also need to be addressed in the future.


5.      Cases of Off-Slot Operation exceeding the Slot Tolerance Times

Based on EU reg 95/93, Art 14, par 4, the Coordinator shall monitor the

  1. Operation of a series of flights at times significantly different from the allocated slots (OFFSLOT)
  2. Operation of an ad hoc flight at times significantly different from the allocated slots (OFFSLOT)

In both cases, the Slot Tolerance times are +/-20 minutes for arriving and departing times (HCAA Airport Regulation 4).


6.      Monitoring Procedures and Methods

Before the Date of Operation

Coordinators should seek to prevent slot misuse by undertaking conformity checks before the date of operation, where possible. The following data sources may be used to detect inconsistencies:

  1. Published schedule data (websites, CRS, timetables, brochures, tickets)
  2. Airport data of the airport concerned or from an airport at the other end of  the route (e.g. cooperation with other coordinators)
  3. ATC flight plans

Coordinators should check for following types of inconsistencies:

  1. intention to operate with no corresponding slot
  2. slot held with no intention to operate. According to WSG, par 7.5, airlines must cancel any operations they will not use as soon as possible. Even at short notice, it may be possible to improve the schedules of other operators
  3. intention to operate at a time different than the allocated slot
  4. intention to use a slot in a significantly different way than allocated (eg use of a different aircraft)

Having detected a discrepancy, the Coordinator should contact the Carrier concerned and ask for an explanation and corrective action in order to prevent misuse.


After the Date of Operation

After the date of operation, Coordinators should compile a database of actual operations compared to allocated slots, updated on a weekly  basis.

These data should be analyzed to detect inconsistencies and identify slot misuse. For this comparison, the Coordinator will use data provided by the airport operator and correlated with other data sources if necessary (e.g. ATC) with actual arrival and departure times.

Coordinators should check for inconsistencies in the use of slots, such as:

  1. operations with no corresponding slot
  2. slot held but not operated
  3. operations at a time different than the allocated slot
  4. use of a slot in a significantly different way than allocated (e.g. use of a different Aircraft)
  5. distinguish repeated (possibly intentional) off slot operations from random operational deviations (Change of A/C due AOG, heavy rotational delays etc)
  6. check whether the deviation is a result of an obvious operational disruption (e.g. known events of extreme weather, strikes, etc).
  7. check for evidence of intentional slot misuse such as published times different than the allocated slot time, or operations closer to the initially requested time than the allocated slot time
  8. check whether the scheduled block time or turnaround time appears appropriate for the route and aircraft type
  9. check whether the scheduled turnaround time of the aircraft operator is realistic in the light of its actual operations.

Follow Up Actions and Cooperation with Carriers

  1. Where there is evidence of a significant discrepancy in the use of slots and/or apparent evidence of intentional slot misuse, the Coordinator should contact in written the Carrier concerned and request an explanation in 05 business days (also in written) in order to take corrective action where necessary.
  2. Coordinators should try to identify slot performance issues as soon as possible  and contact in written the aircraft operator concerned in a timely manner, giving the Carrier the opportunity to take corrective action in a time period agreed with the Coordinator.
  3. For operations without a slot, Coordinators should check whether the reasons invoked by the Carriers to be exempted from slot allocation fall into the exemption reasons indicated in Article 4, par c, of this regulation.
  4. If an adequate explanation is provided and/or appropriate corrective action is taken, the Coordinator should continue to monitor the situation.
  5. If no adequate explanation is provided, the Coordinator may take further appropriate actions.

Actions and Sanctions by the Coordinator

  1. issue a (first) warning
  2. request for corrective actions
  3. summoning before the Coordination or Slot Performance Committee
  4. lower priority in the allocation of slots
  5. loss of historic precedence
  6. according to the the Regulation (EC) No 793/2004 of the European Parliament and of the Council, in case of Air Carriers that repeatedly and intentionally operate air services at a time significantly different from the allocated slot as part of a series of slots or uses slots in a significantly different way from that indicated at the time of allocation and thereby cause prejudice to airport or airtraffic operations, or without prejudice to Article 10(4), if the 80% usage rate as defined in Article 8(2) cannot be achieved by an air carrier, or without prejudice to Article 10(4), if after an allotted time corresponding to 20% of the period of the series validity no slots of that series of slots have been used, the coordinator may activate the articles 14.4 / 14.6.(a) / 14.6.(b) of the Regulation (EC) No 793/2004 of the European Parliament and of the Council.
  7. report the case to the Hellenic Civil Aviation Authority (HCAA) to undertake appropriate legal measures (fine imposition). For Details about Financial Sanctions click here


7.     Monitoring Procedures regarding each type of slot misuse

1. Operation of flights without an allocated slot (goshows): in the absence of explanatory remark staff as received from the airport operator’s data, a first warning will be issued immediately after data processing.

In case of non-response, a second warning will be sent after the 5th business day.

5 business days after the second warning, the unjustified or non justified cases will be forwarded to the Airport Authority for further appropriate actions.

 2. Failure to operate a slot without cancelling it in advance (νοshows): 

 first warning will be issued at the first misuse immediately after data processing.

In case of repeated violations, the 80/20 rule will be applied and the series for the remaining period will be cancelled and sent to slot pool after the completion of 20% of the unused slots. Additionally, the historical precedence for the next equivalent period will be lost.

In the case of fragmented series, a low priority will be given to the fragmented period of series that was not operated.

3. Different service type: forecasting and checking the data for the next weeks and sending a relevant warning.

4. Air carrier’s operation of flights at times different from the allocated slots (offslot): In case of a misuse, a warning will be sent as soon as the first misuse takes place immediately after data processing.

5 working days will be granted for justification and 14 calendar days for compliance.

In the event of non-compliance, the case will be forwarded to the Airport Authority for further appropriate actions.

5. A/c with different seat capacity: Each aircraft seat capacity change will be reviewed on a case-by-case basis, in cooperation with the airport coordinator of the airport (for example, whether or not this seat capacity change was requested, if the change was justified, if the slot was Unable, etc.).

The monitoring department of HSCA will forward the proven misuses to the Airport Authority for further appropriate actions.