Diversion airports are suitable airport capable of handling a particular ETOPS rated airplane during an emergency landing and whose flying distance at the point of emergency shall not exceed the ETOPS diversion period of that particular airplane.

It is, therefore, important that any airports designated as an en route diversion airport have the capabilities, services and facilities to safely support that particular aeroplane and that the weather conditions at the time of arrival provide a high assurance that safe landing is achievable with an engine and/or systems malfunctioning.

An ETOPS flight may only be approved by the ATC if the diversion airports are available throughout the length of the flight. Unavailablity due to bad weather, for example, will be a reason for an inflight rerouting.