Radio Navigator

Radio navigation tracking

Radio navigation is the family of techniques pilots use to fly along a defined ground track using ground-based radio aids. The two workhorse aids are the VOR (a VHF beacon transmitting 360 radials) and the NDB (a low-frequency beacon you home to with an ADF needle). This cluster covers tracking, intercepting, and reading the instruments that interpret these signals.

Articles in this cluster

How to Track a VOR RadialTune, identify, set the OBS, and track a VOR radial inbound or outbound with wind correction. The radial-vs-course gotcha, TO/FROM sense, and worked example.How to Intercept a VOR RadialVOR intercepts: tune, identify, display, set the course, pick an intercept heading, calculate the wind-corrected heading, and roll out based on closure rate.

Frequently asked questions

What is a VOR radial?

A VOR radial is a magnetic bearing FROM a VOR ground station, numbered 0° to 359°. The 270° radial is the line extending due magnetic west from the station. Aircraft track inbound on the reciprocal (090° to follow the 270° radial back to the station).

What is the difference between an HSI and a CDI?

A Course Deviation Indicator (CDI) shows lateral deviation from a selected course on a fixed vertical bar. A Horizontal Situation Indicator (HSI) includes a CDI but the deviation bar rotates with the aircraft heading, combining the CDI with a directional gyro on one face. The HSI improves situational awareness.

How do you intercept a VOR radial?

Select, Tune and Identify the VOR, Display it, set the desired course on the OBS or HSI course pointer. Read the deviation: a deflected needle tells you which side of the course you are on. Turn to an intercept heading typically 30° to 45° off the desired course (steeper for larger deflection or distance), maintain the heading until the needle starts to move, then turn to roll out on the course as the needle centres.

How do you read the ADF needle?

The ADF needle points to the NDB station relative to the aircraft nose (relative bearing). Magnetic bearing TO the station = magnetic heading + relative bearing. Magnetic bearing FROM the station = bearing TO ± 180°. An RMI (Radio Magnetic Indicator) does this addition for you by overlaying the ADF needle on a rotating compass card.

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