Reading the en route chart

Airways, fixes, MEAs, and frequencies, read directly off a real IFR low altitude chart.

16 min read · Charts and procedures

After this lesson you can

  • Tell a Victor airway apart from an RNAV T-route on the same chart, and read the altitude each one publishes.
  • Explain what the "G" suffix on a route MEA means, and why it matters for a non-RNAV aircraft.
  • Read a VOR or VOR/DME frequency box and use it to identify and tune a station shown on the chart.
  • Recognize the boundary of the primary obstacle clearance area and what a printed restriction like "radial unusable" means operationally.

An IFR en route low altitude chart shows almost nothing of the ground: no terrain shading, no roads, none of the visual clutter of a sectional. Its entire vocabulary is airways, fixes, altitudes, and frequencies, because that is everything a pilot in the clouds actually needs between departure and the terminal area.

This lesson reads a real excerpt: the L-34 low altitude en route chart over western Massachusetts and the Berkshires, as published for the cycle printed in its corner. Every frequency, altitude, and note quoted here is taken directly from that chart.

The rest of this lesson

  1. 1.Two networks sharing one chart
  2. 2.MEA, and the G suffix
  3. 3.The protected airspace around an airway
  4. 4.Frequency boxes: reading a VOR station
  5. 5.Airports and restrictions printed along the way
  6. 6.The altitude sigils: what each one actually guarantees

These 6 sections, their figures, the checks along the way and the end-of-lesson quiz come with the IFR track. Paid once, yours for good.

See what the IFR track costsEvery module 1 is free to read, no account, no card.

Key terms

Try to recall each definition before turning the card.