TACAN Navigation System

AIM ¶ 1-1-5 — TACAN Navigation System

AIM 1-1-5 explains TACAN: a military UHF pulse navigation system providing azimuth and distance, integrated with civil VOR/DME as VORTAC facilities.

In Plain English

TACAN (Tactical Air Navigation) is a navigation system developed by the military because the civil VOR/DME system didn't meet their unique operational needs (like landing on pitching and rolling naval vessels or unusual siting conditions). Even though TACAN works on completely different technical principles than VOR/DME, the end result for the pilot is the same: azimuth (bearing) and distance information to a station.

Key points to remember:

TACAN operates in the UHF band and is a pulse system.
It requires dedicated TACAN airborne equipment — your standard VOR receiver cannot use it.
The FAA integrated TACAN with the civil VOR/DME network, creating combined facilities called VORTACs.
A VORTAC provides VOR azimuth for civil aircraft, plus TACAN azimuth and DME distance, all from one site.

Operationally, civilian pilots benefit because the DME portion of a VORTAC comes from the TACAN equipment — that's how your civilian DME receiver gets distance info from a VORTAC. Understanding this integration helps explain why VORTACs appear so frequently on charts and how military and civil aviation share navigation infrastructure.

AIM Source Text

FAA AIM ¶ 1-1-5

1-1-5. 1-1-5. Tactical Air Navigation (TACAN) For reasons peculiar to military or naval operations (unusual siting conditions, the pitching and rolling of a naval vessel, etc.) the civil VOR/Distance Measuring Equipment (DME) system of air navigation was considered unsuitable for military or naval use. A new navigational system, TACAN, was therefore developed by the military and naval forces to more readily lend itself to military and naval requirements. As a result, the FAA has integrated TACAN facilities with the civil VOR/DME program. Although the theoretical, or technical principles of operation of TACAN equipment are quite different from those of VOR/DME facilities, the end result, as far as the navigating pilot is concerned, is the same. These integrated facilities are called VORTACs. TACAN ground equipment consists of either a fixed or mobile transmitting unit. The airborne unit in conjunction with the ground unit reduces the transmitted signal to a visual presentation of both azimuth and distance information. TACAN is a pulse system and operates in the Ultrahigh Frequency (UHF) band of frequencies. Its use requires TACAN airborne equipment and does not operate through conventional VOR equipment.

Oral Exam Questions a DPE Might Ask

Q1What is TACAN and why was it developed?

Per AIM 1-1-5, TACAN (Tactical Air Navigation) is a navigation system developed by military and naval forces because the civil VOR/DME system was considered unsuitable for military/naval use due to unusual siting conditions and the pitching and rolling of naval vessels.

Q2What is a VORTAC, and can a civilian aircraft with only a VOR/DME receiver use one?

Per AIM 1-1-5, a VORTAC is an integrated facility combining civil VOR/DME with military TACAN equipment. Although TACAN itself requires dedicated TACAN airborne equipment and won't work through conventional VOR receivers, the VOR and DME components of a VORTAC are usable by civilian VOR/DME-equipped aircraft, providing the same azimuth and distance information.

Q3What frequency band does TACAN operate in, and what type of signal does it use?

Per AIM 1-1-5, TACAN is a pulse system that operates in the Ultrahigh Frequency (UHF) band.

Related Paragraphs in AIM Chapter 1

¶ 1-1-1

Navigation Aids General

¶ 1-1-10

Simplified Directional Facility

¶ 1-1-11

NAVAID Identifier Removal

¶ 1-1-12

NAVAIDs With Voice

¶ 1-1-13