VOR Test Signal (VOT): Special VOR signal. Example: Bradley (BDL), set 111.4, expect specific indications.
VOR Checkpoint: Specific place on the field.
Airborne Check: Less precise, found in chart supplement, example, fly over specific points.
Dual VOR Check: Compare indications of two VORs.
Airway Check: Example: Victor 16, cross over specific points, check tolerances.
GPS Navigation
Make sure the navigational database is up-to-date.
Conclusion
Both the pilot and aircraft need to be legal and current for IFR flight.
Regularly check equipment inspections, VOR checks, and maintaining proficiency. For more resources, check out flight training videos and articles on Flight-Insight's website.