IFR Flight Planning

033-02-01Pablo Asensio Martínez2026-04-011 min

Route Selection (Airways)

IFR flights typically follow a network of ATS routes (Airways):

  • Upper Airways: High altitude routes (e.g., above FL195 or FL245).
  • Lower Airways: Low altitude routes.
  • RNAV/RNP Routes: Require specific navigational performance (e.g., RNP 1, RNP 5).

Minimum Flight Altitudes

Charts publish safety altitudes to ensure terrain clearance and navigation signal reception:

  • MEA (Minimum En-route Altitude): Ensures obstacle clearance and NAVAID reception.
  • MOCA (Minimum Obstacle Clearance Altitude): Ensures obstacle clearance only (NAVAID range may be limited to 22 NM).
  • Mora (Minimum Off-Route Altitude): Grid MORA provides clearance within a lat/long grid square.

Cruising Levels (RVSM)

Altitudes are allocated based on current RVSM (Reduced Vertical Separation Minima) rules for tracks 000-179 (East) and 180-359 (West).

  • East: FL 290, 310, 330, 350, 370, 390, 410.
  • West: FL 300, 320, 340, 360, 380, 400, 430.
  • Use of Flight Levels (Standard Pressure 1013.25 hPa) typically applies above the Transition Altitude.

Charts

IFR Enroute Chart

  • En-route Charts: Show airways, waypoints, distances, reporting points, and restricted areas.
  • SID/STAR Charts: Standard Instrument Departures and Standard Terminal Arrival Routes connecting the airport to the en-route phase.
  • Instrument Approach Charts: Detailed procedures for landing (ILS, VOR, RNP).
Written and reviewed by

Pablo Asensio · 2026-04-01

Aeronautical engineer. Passed the thirteen EASA ATPL(A) theoretical knowledge exams studying from these very notes. Writes and reviews each topic against the Part-FCL Learning Objectives.

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