Navigation Phraseology (Heading, Radial, QDR, QDM)

Overview

Navigation phraseology refers to standardized radio communication used to describe aircraft orientation, direction, and navigation relative to fixed points like navigation beacons. Understanding this terminology is essential for clear communication between pilots and air traffic control (ATC), especially under instrument flight conditions.

Heading

Definition: The compass direction in which the aircraft’s nose is pointed, expressed in degrees magnetic.
Format: Always given as a three-digit number (e.g., "Heading 090" = due east).

Phraseology:

“Fly heading zero nine zero”
“Turn left heading two seven zero”

Notes:

Headings are magnetic, not true bearings.
Rounded to the nearest 10 degrees in most cases.
Used by ATC for vectoring traffic.

Radial

Definition: A line extending outward from a VOR (VHF Omnidirectional Range) station, identified by a bearing (in degrees) from the station.
Format: Always referenced from the VOR station, not to it.

Phraseology:

“Proceed on the one-eight-zero radial from Vienna VOR”
“Cross the two-four-zero radial”

Example: The 090 radial from a VOR means you are on the east side of the station, flying away from it.

QDM and QDR

Term	Meaning	Direction	Use
QDM	Magnetic heading to the station	“Where do I steer to reach the station?”	Navigation to a beacon
QDR	Magnetic bearing from the station	“What’s my bearing from the station?”	Position reporting or D/F steered recovery

“Request QDM” → Response: “QDM 123” (steer heading 123 to reach the station)
“Your QDR is 270” (you are west of the station)

Mnemonic:

QDM – “Direct to the beacon”
QDR – “Direction out, radial”

Practical Use

These terms are essential in non-GPS navigation, especially when working with VORs and DF (Direction Finding) stations.
Phraseology must be precise to avoid misunderstandings, especially during low visibility or under IFR conditions.