Radial and Bearing from Navigation Station in Aviation Navigation

Heading

Definition:
Heading is the compass direction in which the aircraft’s nose is pointed, measured in degrees clockwise from north (usually magnetic north). Heading is displayed on the aircraft’s instruments and is controlled by the pilot.

Operational Context:
Heading is used throughout flight—from taxi, takeoff, and cruise, to landing. It does not account for wind drift; thus, heading often differs from the aircraft’s actual path (track) over the ground.

Advanced Notes:
Most aviation uses magnetic heading, but some operations use true heading, especially near the poles. Heading is also set on autopilots and is a key value for navigation displays.

Common Mistake:
Do not confuse heading (aircraft nose direction) with track (actual movement over the ground) or course (intended route).

Track

Definition:
Track is the actual path over the ground that the aircraft follows, given in degrees from north. Track reflects the effect of wind drift on the aircraft’s movement.

Instrumentation:
GPS and modern avionics display track in real-time, typically labeled as “TRK” on flight displays or moving maps.

Role in Navigation:
Track is the path the aircraft actually makes. Pilots adjust heading to counteract wind so that the track matches the intended course. The difference between heading and track is called the wind correction angle (WCA).

Common Pitfall:
New pilots often confuse heading (where you point) and track (where you go). ATC may request “maintain present track” or “fly a track of 270°.”

Course

Definition:
Course is the planned or intended direction of flight over the ground, measured in degrees from north. It is the line pilots plan to follow during flight planning and navigation.

Usage:
Pilots set courses between waypoints using charts or FMS programming. The course is depicted as a straight line on charts and navigational displays.

Distinction:

• Heading: where the nose points
• Track: actual ground path
• Course: intended route

Example:
To maintain a course of 270°, a pilot may need to fly a heading of 285° if there’s a strong north wind. The track (actual path) should match the course if the wind correction is accurate.

Bearing

Definition:
Bearing is the direction from the aircraft to a navigation station, fix, or waypoint, measured in degrees from north. Bearing can be true, magnetic, or relative (from the aircraft’s nose).

Types:

• True Bearing: From true north to the station
• Magnetic Bearing: From magnetic north to the station
• Relative Bearing: From the aircraft’s nose clockwise to the station

Usage:
Bearings are used with VOR, ADF/NDB, GPS, and other navigation aids. The bearing points toward the station from the aircraft’s current position.

Key Clarification:

• Bearing is to the station from the aircraft.
• Radial is from the station to the aircraft.

Radial

Definition:
A radial is a magnetic compass line extending outward from a VOR or TACAN station, measured clockwise from magnetic north. Each radial corresponds to a specific magnetic bearing from the station.

Use:
Radials define airways, approaches, and holds. Your aircraft’s position relative to a VOR is given by the radial you are on.

How to Find Your Radial:
Tune the VOR, center the CDI with a FROM indication; the number set on the OBS is the radial you are on.

Radial vs. Bearing:

• Radial: from station out to aircraft
• Bearing: from aircraft to station (reciprocal of radial)

Comparative Table: Radial vs. Bearing and Related Terms

Detailed Examples and Scenarios

Example 1: VOR Navigation—Radial and Bearing

If you are due west of a VOR on the 270 radial, the bearing to the station is 090°. If instructed to intercept the 270 radial, fly to the line extending west from the station. To fly toward the VOR along the 270 radial, set your course to 090° (reciprocal).

Key:

• Radial = Position from station out
• Bearing = Direction to station from aircraft

Example 2: Inbound vs. Outbound on a Radial

On the 090 radial (east of the VOR), flying east is outbound on the 090 radial. Turning around and flying west is inbound on the same radial. The course set would be 270°.

Example 3: Heading and Track to Maintain a Radial

Flying inbound to the station on the 090 radial (from east), intended course is 270°. A north wind may require a heading of 260° to maintain that course.

Practical Applications and Use Cases

Communicating with ATC:
“Intercept the 180 radial of XYZ VOR” or “Report established on the 270 radial, 15 miles DME.” Clear terminology prevents navigation errors.

Situational Awareness:
Triangulate position using bearings from two VORs. In military aviation, the “bullseye” is a reference point for giving positions as radial and distance.

Instrument Approaches and Holds:
Approach and holding procedures use radials and distances (DME) for safe navigation.

Instrumentation and Navigation Displays

VOR Receiver (CDI/OBS)

The OBS allows course selection (radial), and the CDI needle shows lateral deviation. The TO/FROM flag indicates direction to/from the station.

GPS and Bearing

Modern GPS displays bearing, course, track, and heading simultaneously for situational awareness.

NDB and ADF

ADF needles point to the NDB. Relative bearing + heading = magnetic bearing to the station.

Visual Aids and Chart Annotations

Charts depict VOR radials as lines from the station, labeled with magnetic direction (e.g., R-090). Airways and fixes are defined by radials and DME.

Common Errors and Clarifications

• You are on a radial, not “on a bearing.”
• Radial: from station out. Bearing: from aircraft to station.
• Heading ≠ radial or bearing—heading is the aircraft’s nose direction.
• Confusing radial and bearing can cause navigation errors.

Calculation Formulas

Heading Correction

True Course ± Wind Correction Angle (WCA) = True Heading
True Heading ± Magnetic Variation = Magnetic Heading
Magnetic Heading ± Deviation = Compass Heading

Radial and Bearing Relationship

• Radial = Magnetic bearing from station to aircraft
• Bearing = Magnetic bearing from aircraft to station = (Radial + 180) % 360

Understanding and correctly using heading, track, course, bearing, and radial is essential for safe, accurate navigation and communication in aviation. Mastery of these concepts underpins all phases of flight, from pre-flight planning to approach and landing.