FAA Instrument Rating Airplane (IRA)IFR Procedures and ChartsMedium

A pilot is flying an IFR flight in an area depicting a Minimum Off-Route Altitude (MORA) of 10,000 feet. The aircraft is equipped with a non-WAAS GPS, and the pilot is navigating off-airway using direct-to waypoints. The current altitude is 8,000 feet MSL. What is the significance of the 10,000-foot MORA in this situation?

  1. AIt provides 1,000 feet of obstacle clearance (2,000 feet in mountainous terrain).
  2. BIt is the minimum altitude at which ATC can vector the aircraft in the area.
  3. CIt indicates the lowest altitude for radar coverage in the area.
  4. DIt guarantees navigation signal reception for the area.
Show answer & explanation

Correct answer: A. It provides 1,000 feet of obstacle clearance (2,000 feet in mountainous terrain).

A Minimum Off-Route Altitude (MORA) or Off-Route Obstacle Clearance Altitude (OROCA) is an altitude depicted on IFR en route charts (usually in grids). It guarantees obstacle clearance (1,000 feet in non-mountainous, 2,000 feet in mountainous areas) within 10 nautical miles on either side of the center line of an airway or route segment, or within a grid area. It does NOT guarantee navigation signal reception or communication coverage.

Why the other options are wrong

  • B. Minimum Vectoring Altitudes (MVAs) are for ATC use and are generally lower, designed for specific radar coverage.
  • C. MORA/OROCA does not guarantee radar coverage; that's related to MVA and radar capabilities.
  • D. MORA/OROCA does not guarantee navigation signal reception.

Minimum Off-Route Altitude (MORA)

An altitude depicted on IFR en route charts (either grid MORA or route MORA) that provides obstacle clearance (1,000 feet in non-mountainous, 2,000 feet in mountainous terrain) within a specified area or along a route segment.

  • Provides obstacle clearance only.
  • Does NOT guarantee navigation signal reception.
  • Does NOT guarantee communication or radar coverage.
  • Found on IFR en route low/high altitude charts.

Memory trick: MORA: 'Obstacle Clearance is All' it provides.

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