Proposal to Change VOR Equipment Test

A pilot has proposed removing the requirement to log the results of the VOR equipment test required by 14 CFR § 91.171 for operations under IFR.

You can read the original proposal, docket FAA-2019-0739, and comments at the Federal Register, here.

The change wouldn’t repeal the test itself, only the detailed requirements for recording the results as described in paragraph (d).

AOPA filed detailed comments in support of the proposal, here. The organization notes in part that: “The logging requirement is not a positive safety argument when a failed check is what is clearly the concern. A failed check is fully and effectively mitigated by the placarding requirement of 14 C.F.R. §91.213 and the obligations under 91.171(a).”

I support the proposal, but in comments that I submitted to the docket, I suggested additional changes, viz.:

  • Expand the current 30-day limit to a more reasonable interval, such as every three calendar months or six calendar months. Using the calendar month criterion would synchronize the interval with other regulatory requirements, such as the valid periods for medical certificates, annual inspections, flight reviews, and so forth.
  • Allow the use of an IFR-approved GNSS (i.e., a suitable RNAV system, as described in AIM 1−2−3 Use of Suitable Area Navigation (RNAV) Systems on Conventional Procedures and Routes, and as defined in various ACs, including AC 90−100A) to verify the accuracy of VOR equipment.

As I explained:

For example, a pilot tracking an airway or a course to/from a VOR with an IFR-approved GNSS could confirm that the VOR course shown by a CDI or bearing pointer is within the limits specified by the regulation. As other commentators have noted, FAA is gradually decommissioning VORs, and accomplishing the VOR equipment test will become increasingly difficult as navaids are removed from the NAS. Even given the inherent differences between the courses shown by GNSS and conventional navaids, as described in the AIM (1−1−17. Global Positioning System (GPS), Paragraph k. Impact of Magnetic Variation on PBN Systems), checking the accuracy of a VOR in this manner would be well within the six-degree error long permitted for airborne checks. Using GNSS would also be in keeping with current FAA policy about PBN in general, and specifically about using GNSS to fly conventional procedures while monitoring guidance from ground-based navaids.