Reading VTC & VNC Charts Without the Headache

You’ve mastered the controls of your RPAS, you understand the Standard Operating Conditions, and you’re ready to plan a flight. You open a CASA-verified drone app, and it gives you a green light. Good to go, right?

Mostly. But what happens when you open the official aviation chart for that area and are confronted with a dizzying maze of lines, circles, numbers, and cryptic codes? It’s enough to give anyone a headache. This is a common feeling for new remote pilots, but learning to read these charts is a fundamental skill that separates a true aviation professional from an amateur.

Drone safety apps are excellent for a quick “go/no-go” check, but they are a summary, not the source document. Understanding the source—the Visual Terminal Chart (VTC) or Visual Navigation Chart (VNC)—gives you a deeper situational awareness, helps you plan more complex missions, and proves your professionalism to clients and regulators.

This guide will demystify these charts, focusing on the key elements you, as an RPAS pilot, absolutely need to know.

 

1. VTC vs. VNC: Choosing the Right Map for the Job

 

First, let’s look at the two main types of visual charts you’ll encounter in Australia. They are both published by Airservices Australia.

• VNC (Visual Navigation Chart): Think of this as a state or regional map. It has a scale of 1:500,000, meaning it covers a very large area with less detail. VNCs are used by crewed aircraft for navigating between towns and cities. As a drone pilot, you might use it for planning a job in a regional or rural area, far from major airports.
• VTC (Visual Terminal Chart): This is your detailed city map. At a scale of 1:250,000, a VTC provides much more detail about a smaller, busier piece of airspace—specifically, the airspace around major airports and their surrounding metropolitan areas.

Rule of Thumb: If your operation is anywhere near a capital city or major regional airport (think Sydney, Melbourne, Bankstown, Cairns, etc.), you will need the VTC. For everything else, the VNC will suffice.

 

2. Decoding the Core Elements: What You Actually Need to Look For

 

When you first open a VTC, don’t try to understand everything at once. Focus on the big-picture items that most directly impact your sub-120 metre (400 ft) drone flights.

 

Airports and Aerodromes

 

This is the central feature of most VTCs. You can spot them easily.

• Controlled Aerodromes (Blue): These are depicted in blue and represent major airports with an active control tower (e.g., Sydney Airport, Brisbane Airport). They are surrounded by the most restrictive airspace.
• Uncontrolled Aerodromes (Magenta): These are shown in magenta and are typically smaller airfields or private airstrips without a control tower. While less restrictive, you still need to be highly vigilant for other aircraft, which could be taking off or landing in any direction.

 

The Big Numbers: Understanding Elevation and Altitude

 

The chart is covered in numbers, but two types are critically important for your planning.

• Maximum Elevation Figure (MEF): Look for the large blue numbers that dominate each grid square on the map (a grid square is defined by the lines of latitude and longitude). For example, you might see a big blue 45, which represents an altitude of 4500 feet Above Mean Sea Level (AMSL). The MEF tells you the highest point (terrain or obstacle) within that grid square, rounded up. For an RPAS pilot, this is an immediate, at-a-glance guide to how high the terrain and towers are in your intended operational area.
• Spot Elevations: These are smaller black numbers, often with a dot, scattered around the map. They indicate the AMSL height of a specific point, like a hilltop (•1770) or a tall obstacle like a radio tower (1121 with a tower symbol). Always be on the lookout for these obstacles.

 

The Lines and Circles: This is the Airspace!

 

This is the part that causes the most confusion, but it’s simpler than it looks. Think of airspace as an invisible, upside-down wedding cake layered on top of the map. Your job is to know if you’re flying under one of the “layers” or if a layer comes all the way down to the ground.

• Control Zone (CTR): This is the core of the airspace, immediately surrounding a controlled (blue) aerodrome. It is usually depicted by a dashed blue line. A CTR is the most restrictive piece of airspace for a drone pilot because it starts at the ground, or ‘Surface’ (SFC). The chart will label it with something like CTR C SFC to 2500. This means Class C controlled airspace exists from the Surface up to 2500 ft. You cannot fly a drone inside a CTR without complex, formal permission from CASA and Airservices Australia. If your job is inside the dashed blue line, it requires a significant amount of extra planning and approval.
• Control Area (CTA): This is the “upside-down wedding cake.” CTA describes the steps of controlled airspace that get progressively higher as you move away from the airport. On a chart, these are marked by solid blue lines with text like C LL 2500. This means Class C airspace has a Lower Limit (LL) of 2500 ft in that sector.
  • This is the key takeaway! If the floor of controlled airspace is at 2500 ft, and you are legally required to fly below 400 ft (120 m), you can operate safely and legally underneath that airspace layer. Your drone safety app does this calculation for you, but understanding it on the chart yourself is a game-changer.
• PRD Areas (Prohibited, Restricted, Danger): These are areas marked with hatched lines and a code (e.g., R339A).
  • Prohibited (P): No-go. You cannot fly here (e.g., Pine Gap).
  • Restricted (R): Flying is restricted, usually due to military activities. You cannot fly here when the area is active. The chart or supporting documents will tell you when it’s active. Assume it’s always active unless you can prove otherwise.
  • Danger (D): Activities dangerous to aircraft may be taking place (e.g., firing ranges). You are technically allowed to fly, but it’s not advisable without checking its status.

 

3. A Practical Walkthrough

 

Let’s imagine you have a real estate job in the suburbs, 15 km west of Brisbane Airport.

1. Open the Brisbane VTC. Find the property’s location on the chart.
2. Check the MEF. You see the big blue number in that grid is 21, meaning the highest point is around 2100 ft. Your 400 ft flight is well below that.
3. Look for Airspace Lines. You are outside the inner Control Zone (CTR). You see a solid blue line between you and the airport. On that line, you read C LL 1500.
4. Interpret the Data. This means the floor of the Class C controlled airspace above your job site starts at 1500 ft.
5. Check for PRD Areas. You scan the area and see no hatched PRD zones nearby.
6. Conclusion: Because your flight will be conducted below 400 ft AGL, and the controlled airspace doesn’t start until 1500 ft AMSL, you have a “clear sky” above you. You can confidently proceed with the mission, provided you follow all other CASA rules (maintaining VLOS, staying 30m from people, etc.).

 

Final Thoughts: From Chart to Cockpit

 

Learning to read VTC and VNC charts is a skill that takes practice. Start by reviewing the charts for your local area. Identify the key features we’ve discussed. Trace the CTA steps and see how the airspace floor rises and falls.

While digital apps are your go-to tool for on-the-day final checks and identifying temporary restrictions (NOTAMs), the chart is your master document for professional planning and true situational awareness.

Embracing this skill doesn’t just keep you safe and compliant—it fundamentally elevates you from someone who simply operates a drone to a knowledgeable and professional Remote Pilot.