What is minimum reception altitude (MRA)?

• A. The altitude at which you must start the approach.
• B. The lowest altitude at which an airway intersection can be determined.
• C. The altitude at which you can begin the missed approach.
• D. The altitude of the final approach fix.

Answer: (B)

Minimum reception altitude is the lowest altitude at which you can reliably receive a ground-based navigation signal well enough to identify an airway intersection. This matters for enroute navigation because, to determine your position at a defined fix, you must have adequate signal reception from the navigation aid (such as a VOR or NDB). Below this altitude, reception may be unreliable, making it difficult or impossible to determine that intersection precisely. It’s not about when to start an approach, nor the missed-approach altitude, nor the altitude of the final approach fix. The MRA specifically indicates the altitude needed for dependable fix identification from the nav aid's signal, reflecting radio coverage rather than obstacle clearance or approach procedures.