En-route chart

In aviation, an en-route chart is an aeronautical chart that guides pilots flying under instrument flight rules (IFR) during the en-route phase of flight.

FAA low-altitude en-route chart for the Seattle region

Overview

An en-route (also known as en route^[1] or enroute^[2]) chart provides detailed information useful for instrument flight, including information on radionavigation aids (navaids) such as VORs and NDBs, navigational fixes (waypoints and intersections), standard airways, airport locations, minimum altitudes, and so on. Information not directly relevant to instrument navigation, such as visual landmarks and terrain features, is not included.

En-route charts are divided into high and low versions, with information on airways and navaids for high- and low-altitude flight, respectively. The division between low altitude and high altitude is usually defined as the altitude that marks transition to flight levels (in the United States, this is taken to be 18,000 feet MSL by convention).

Historically, they were called air navigation maps, airway maps, and flight charts.^{[3][failed verification][4][failed verification]}

Modern use

In addition to paper charts, most pilots now access en-route charts through electronic flight bag (EFB) applications, which integrate updated aeronautical data with navigation displays. These digital charts are updated automatically in line with the 28-day AIRAC cycle, reducing the risk of outdated information in flight operations. In regions adopting Performance-Based Navigation (PBN), en-route charts may include curved radius-to-fix (RF) paths and advanced Required Navigation Performance (RNP) routes. Digital en-route charts are also increasingly used in helicopter operations and low-level IFR routes, such as those implemented in the United States and China.^[5]

See also

• Index of aviation articles
• Moving map display