Description of slot monitoring


In accordance with the amended European Council Regulation N°95/93 on the allocation of slots, the national legislation, the IATA Worldwide Slot Guidelines (WSG) and local rules, COHOR monitors the usage and the adherence of slot allocated to the air carriers and operators of general and business aviation on the French coordinated airports.

In addition, COHOR also applies the Recommended Practices developed by the European Airport Coordinators Association (EUACA) on the control of the usage of slots.


 1.  COHOR’s assignement

Identify the potential misuses comparing flight plans and slots. 

For each flight coming to or from a French coordinated airport, COHORmakes, from 4 hours before the departure time of its origin as mentioned in the filed flight plan submitted to the air traffic control services, a comparison between the data of the flight plan and the allocated slot on the French coordinated airport concerned.

When a misuse is detected, such as:

  • flight plan without any slot associated
  • flight plan with characteristics significantly different from the allocated slot
  • missing identification number (slot ID) on the general or business aviation flight plan
  • other cases

a message is generated to the flight plan issuer in order for him to take all necessary actions to ensure compliance between the flight plan and/or the slot on the relevant French coordinated airport(s).

If no action is carried out following the sending of this warning message, the flight plan of a flight willing to operate without an allocated slot on a coordinated airport, for the period which the airport is coordinated, may be suspended by the authorities.

Therefore, we strongly recommend air carriers to warn their operational services in charge of flight plan process, to carefully consider these warning messages that are sent by the German air traffic control services (DFS, Deutsche FlugSicherrung) on behalf of their French counterpart (DSNA, Direction des Services de la Navigation Aérienne). This awareness is particularly important when the flight plan process services are outsourced.

Identify cases of misuse of slots

 COHOR compares the data of the operated flights with the allocated slots in order to detect:

  • Flight operated without slot
  • Flight operated in different conditions from the allocated slot. In particular at a different schedule.
  • Allocated slots not used by air carriers, resulting in a waste of airport capacity. 

COHOR processes those cases of slot misuse or presumed breach of regulation by requiring justifications to operators or to their handlers for general or business aviation, when necessary.

In their own interest, we request air carriers being questioned on such cases of misuse to answer as early as possible the demand of explanations sent byCOHOR. Answer shall be sent to the communicated address.

Then, COHOR communicates the results of the investigations for each alleged infringement to the French Civil Aviation Authority (DGAC). In turn, DGAC processes each case of infringements and then send the files to the Administrative Committee of the Civil Aviation (CAAC).

This committee is appointed by the Minister in charge of Transport and is composed of the following:

·         Representatives of Civil Aviation
·         Representatives of air carriers
·         Representatives of airports
·         Representatives of air transport police
CAAC convenes air carriers in order to hear their circumstances on the breach of regulation and evaluates the administrative fine that will be submitted to the Minister in charge of transport if the infringement is confirmed. The Minister then decides, if necessary, the final sanction.
Link to sanctions recently pronounced by the Minister on the proposal of the CAAC:

Exception: Departure flights from Charles De Gaulle Airport during the night (between 00:00 and 04:59 local time) on the breach of regulation of the 06th of November 2003, are punishable by an independent Authority, named ACNUSA ( The detected infringements will follow a different process and the fine can be much more expensive.   

2.  Slot Performance committee (SUC)

The SUC is a subcommittee of the French airports coordination committee. It is composed of air carriers or representative associations, airports, French civil aviation (DGAC) and COHOR.

The committee meets twice a year at each end of IATA season.

The SUC reviews the problems encountered on coordinated airports relative to a misuse of slots, and proposes some operational solutions either to the air carriers concerned or to the French airports coordination committee.