Definition
A two-character classification code used in the composition of route and procedure designators that indicates a route is established for navigation by aircraft equipped with specific area navigation (RNAV) capability, where 'NAV' identifies the navigation specification category and 'E2' identifies the particular equipment or performance level required to fly that route.
Plain English
A short label attached to a route name that tells the pilot what kind of navigation equipment the aircraft must have on board to be allowed to fly that route.
Context Anchor
Seen when completing or reading an ICAO flight plan, especially the NAV/ entry that lists navigation capability for departure, en route, and arrival operations.
Derivation
NAV' is short for navigation. The 'E2' is a category code from the international system used to classify routes by the navigation performance required. Knowing this helps the reader see that the code is a label about equipment requirements, not a route name on its own.
Why Pilots Care
It tells the pilot whether the aircraft's installed navigation systems are approved for that procedure.
Grounding Statement
If you file NAV/E2, you are saying the aircraft can accurately follow an approved en route RNAV path, not merely that it has a navigation display or GPS receiver installed.
Intuition Check
Do not read E2 as an equipment model or a radio code. Here, E2 means RNAV 2 capability for the en route portion of an instrument flight.
Example Sentence 1
Before accepting the clearance, she checked that her aircraft's avionics met the NAV/E2 code requirements listed for the route.
Example Sentence 2
Before departure the dispatcher checks the NAV/E2 code against the airplane's equipment list.