Title: Describe regulations related to VOR systems.
Course: Aircraft Pilot Training II (20053-II) > Section: Operating the Aircraft

Description should include the following:

- No person may operate a civil aircraft under IFR using the VOR system of radio navigation unless the VOR equipment of that aircraft
  - is maintained, checked, and inspected under an approved procedure; or
  - has been operationally checked within the preceding 30 days, and was found to be within the limits of the permissible indicated bearing error

PLT508