IFATCA Policy is:

The implementation of 8.33 kHz channel spacing should not take place until the speech quality has been tested in a realistic operational environment to ensure that flight safety will not be jeopardised.

To limit controller workload, the procedures and equipment to identify non-equipped aircraft and to deal with the mixed operational environment shall be in place before 8.33 kHz spacing is introduced.

Prior to the introduction of 8.33 kHz the following conditions must be met:

• Appropriate “filtering / gate keeping” procedures shall be in place when apropriate.
• Detection of 8.33 KHz equipage and the display of non-equipped status to the controller shall be in place.
• Education programmes for pilots and controllers shall be completed. This is particularly important in states surrounding 8.33 kHz airspace which perform the “filtering / gate keeping” procedures.
• Procedures which consider a controller as the principle means of mitigation are unacceptable.
• Last minute diversions and sub-versions of non-equipped aircraft directly affect the capacity of the sectors involved therefore such re-routings shall be kept to the absolute minima in order that the safe operations of the sectors involved are not degraded.
• 121.5 MHz shall not be considered as a contingency frequency for non-equipped aircraft nor can it be used to re-route or divert aircraft that are not equipped.
• A 25 kHz independent contingency frequency shall be available to re-route non-equipped aircraft.
• Non-equipped medical flights shall only be accommodated in the case of an in-flight emergency.
• The introduction and use of 8.33 kHz spacing shall be proven to meet at least the pre-existing target levels of safety.