True Track vs Magnetic Track vs Compass Track: Essential Navigation for PPL Students
As a student pilot working towards your Private Pilot License (PPL), understanding the relationship between True Track, Magnetic Track, and Compass Track is fundamental to safe and accurate navigation. These three types of track form the backbone of aircraft navigation, and mastering their differences is crucial for both your theory exams and real-world flying.
What is Track in Aviation?
Before diving into the specific types, let's establish what track means in aviation. Track is the actual path that an aircraft follows over the ground, measured as an angle from a reference direction. This differs from heading, which is the direction the aircraft's nose is pointing.
Key Point: Track = the path over the ground | Heading = where the nose points
The three types of track differ based on their reference point: True North, Magnetic North, or what your compass actually shows.
True Track (TT)
True Track is the angle between True North and the aircraft's track over the ground, measured clockwise from 000° to 360°.
Characteristics of True Track:
- Referenced to True North (geographic North Pole)
- Remains constant regardless of location
- Used in precise navigation calculations
- Found on charts and GPS systems
- The "purest" form of directional measurement
When Do We Use True Track?
- Long-distance flight planning
- GPS navigation systems
- Celestial navigation
- Chart plotting and measuring
Pro Tip: When measuring tracks on charts using a protractor or plotter, you're measuring True Track unless the chart specifically indicates otherwise.
Magnetic Track (MT)
Magnetic Track is the angle between Magnetic North and the aircraft's track over the ground, measured clockwise from 000° to 360°.
Understanding Magnetic Variation
To understand Magnetic Track, you must first grasp magnetic variation (or declination). This is the angular difference between True North and Magnetic North at any given location.
Key factors about magnetic variation:
- Varies by geographic location
- Changes slowly over time
- Shown on aviation charts with isogonal lines
- Can be either East or West of True North
The True to Magnetic Conversion
The relationship between True Track and Magnetic Track follows this formula:
Magnetic Track = True Track ± Variation
- Subtract variation when it's East: "East is least"
- Add variation when it's West: "West is best"
Practical Example:
- True Track: 090°
- Variation: 5°W
- Magnetic Track: 090° + 5° = 095°
When Do We Use Magnetic Track?
- VOR navigation
- ADF bearings
- Most radio navigation aids
- Air Traffic Control communications
- Standard navigation procedures
EASA Regulation Note: According to EASA Part-FCL, PPL students must demonstrate competency in magnetic compass navigation, making understanding of Magnetic Track essential.
Compass Track (CT)
Compass Track is what your aircraft's magnetic compass actually shows for your track over the ground. This is where theory meets reality, as your compass reading will differ from the calculated Magnetic Track due to compass deviation.
Understanding Compass Deviation
Compass deviation is the error in compass readings caused by magnetic interference within the aircraft itself. Sources include:
- Aircraft's metal structure
- Electrical systems
- Radio equipment
- Engine components
- Electronic devices
Deviation Characteristics:
- Varies with aircraft heading
- Unique to each individual aircraft
- Recorded on a compass deviation card
- Can be positive (East) or negative (West)
- Should be minimized through compass swinging
The Complete Navigation Formula
The relationship between all three tracks follows this sequence:
True Track → Magnetic Track → Compass Track
Or in one step: Compass Track = True Track ± Variation ± Deviation
Memory Aid: "True Virgins Make Dull Company"
- True (Track)
- Virgins (Variation)
- Make (Magnetic Track)
- Dull (Deviation)
- Company (Compass Track)
Practical Application in Flight Planning
Step-by-Step Navigation Planning
Real-World Example:
Scenario: Flight from London to Birmingham
- True Track (measured on chart): 315°
- Local variation: 1°W
- Compass deviation for 314° heading: +2°
- Magnetic Track: 315° + 1° = 316°
- Compass Track: 316° + 2° = 318°
Common Student Mistakes and How to Avoid Them
Mistake #1: Confusing Track with Heading
Solution: Remember that track is your path over the ground, while heading is where you point the aircraft to achieve that track.Mistake #2: Wrong Variation Application
Solution: Use the memory aids "East is least, West is best" or remember that easterly variation makes magnetic readings smaller than true.Mistake #3: Ignoring Compass Deviation
Solution: Always check your aircraft's compass deviation card and apply corrections accordingly.Mistake #4: Using Wrong Reference Lines on Charts
Solution: Ensure you're using the correct compass rose or meridian when measuring tracks.Technology and Modern Navigation
While GPS provides accurate True Track information, understanding magnetic and compass tracks remains vital because:
- Backup navigation requirements
- Radio navigation aids still use magnetic references
- ATC communications use magnetic directions
- Compass navigation is required for PPL certification
- Electronic systems can fail
Important: EASA FCL.010 requires pilots to demonstrate competency in traditional navigation methods, regardless of available technology.
Exam Preparation Tips
Key Points to Remember:
- True Track: Referenced to True North, used for chart work
- Magnetic Track: Referenced to Magnetic North, used for radio navigation
- Compass Track: What your compass shows, includes deviation errors
- Variation: Geographic difference between True and Magnetic North
- Deviation: Aircraft-specific compass errors
Practice Questions:
Answers:
Conclusion
Mastering the differences between True Track, Magnetic Track, and Compass Track is essential for safe navigation and PPL success. While modern technology provides excellent navigation aids, understanding these fundamental concepts ensures you can navigate accurately in any situation and provides the foundation for advanced navigation techniques.
Practice these concepts regularly, and always cross-check your calculations. Remember that aviation navigation is about understanding the relationship between these different references and applying them systematically for safe and accurate flight.
Final Tip: Create your own navigation problems using local charts and practice the conversions until they become second nature. This knowledge will serve you throughout your aviation career.