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AhaBulb: Stuff Everyone Should Know · ahabulb.com/pilot-vor-line-of-sight

Why might a VOR receiver show an OFF flag when you are flying low and far from the station?

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  1. VORs only work at night
  2. VOR signals travel in a line of sight
  3. The VOR is always under maintenance

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References

  1. FAA Pilot's Handbook of Aeronautical Knowledge, Chapter 16 www.faa.gov/sites/faa.gov/files/18_phak_ch16.pdf Checked 2026-10-09.
  2. FAA AIM 1-1-8, NAVAID Service Volumes www.faa.gov/air_traffic/publications/atpubs/aim_html/chap1_section_1.html Checked 2026-10-09.

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