IFR Enroute High Altitude Charts

An IFR enroute high altitude chart is an FAA navigation chart used for flight at or above 18,000 ft MSL in Class A airspace. It maps the jet route and high-altitude RNAV system pilots fly in the flight levels, leaving off the low-level Victor airways so only the high-altitude route structure remains.

High altitude charts cover flight at or above 18,000 ft MSL and show jet routes and high-altitude RNAV routes. Low altitude charts cover flight below 18,000 ft MSL and show Victor airways. Most pilots flying in the flight levels carry high altitude charts; those operating down low use the low altitude set.

You use a high altitude enroute chart when navigating at or above 18,000 ft MSL, the floor of Class A airspace. That range runs from FL180 up to FL600 and is where the jet route system and high-altitude RNAV routes are flown, so any IFR flight climbing into the flight levels needs one.

Six chart pairs, numbered H1/2 through H11/12, cover the conterminous United States. Rather than buy all six, plot your route on the FAA coverage index and order only the pairs your flight crosses. Alaska is covered separately by its own high-altitude charts.

Jet routes are the published airways flown at or above 18,000 ft MSL, up to FL450. They are established using VOR and VORTAC NAVAIDs spaced not more than 260 nautical miles apart and are identified with a J prefix, forming the backbone of the high-altitude route structure these charts depict.

FAA IFR enroute high altitude charts are revised on the standard 56-day chart cycle. Each new edition supersedes the prior one, and pilots are required to navigate with the current edition, so replace your charts each cycle to keep your cockpit legal and accurate.