Operational Air Traffic rules (OAT) allow military pilots to conduct operations not covered by EUROCONTROL General Air Traffic (GAT) rules. For example, aerial refueling, formation flying, air combat maneuvering, etc.
OAT flight plans can be filed with ForeFlight. To file an OAT flight plan, manually modify the route to specify which portion of the flight will be conducted under OAT rules.
Applying a rule change
Flights are assumed to operate under GAT rules. To file a flight plan under OAT rules, specify in the route when the flight rules will change. If a flight rule change to OAT is specified, the flight plan must specify when GAT rules will be resumed.
To specify rule changes, append the following notation to the waypoint where the change is to occur.
/OAT - Specifies when flight under Operational Air Traffic rules will commence.
/GAT - Specifies when flight under General Air Traffic rules will resume.
Flight rule changes can be specified in Flights or on the filing form. Applying rule changes to the filing form (after selecting Proceed to File) is recommended. Adding rule changes to the Flights page results in errors. The errors do not prevent the flight plan from being filed.
NOTE: Prior to applying a rule change, pilots should verify the route is EUROCONTROL valid to reduce the chances of a filing rejection.