VOR, VORTAC, and TACAN aids are classed according to their operational use. The three classes of NAVAIDs are:
- T – Terminal.
- L – Low altitude.
- H – High altitude. The normal service range for T, L, and H class aids is found in the AIM. Restrictions to service range are listed in the Chart Supplement.
Source FAA Pilot/Controller Glossary · checked 2026-08-25