Enroute - High Altitude Charts
The following legend, applicable to High Altitude Charts only, is in addition to the other parts of the
Enroute chart legend. Many items in the other parts of the legend are also applicable to the High
Altitude Charts.
VHF, L/MF Navigational Facilities.
Geographical coordinates (latitude and longitude) of each facility are shown across the bottom of the
facility box.
The letter (H) indicates an H-class facility. The letter (L) indicates an L-class facility. The letter (T)
indicates a T-Class facility. "D" indicates the availability of DME. In areas of congestion, off-route
facility geographical coordinates are shown in an alphabetical listing elsewhere on the chart.
US High Altitude "Enroute Flight Advisory Service". Name of Air Route Traffic Control Center to call,
followed by "FLIGHT WATCH". Remote outlet name is included within parentheses. Service is
provided between 0600 and 2200 daily.
Jet routes. The thin route centerline is used on United States and Canada-Alaska chart series in
areas of congestion.
Canada LF/MF High Level airways.
Europe high level airway/route.
