9.2 Visual Terminal Charts and Visual Navigation Charts

Visual Terminal Charts and Visual Navigation Charts

For a CASA Remote Pilot Licence (RePL) holder operating under the standard operating conditions, visual navigation is the primary means of deciding where you can and cannot fly. Two chart series do most of the work: the Visual Terminal Chart (VTC) and the Visual Navigation Chart (VNC). Both are published by Airservices Australia and are the official pictorial representation of airspace, terrain, and hazards for visual flight rules (VFR) pilots. As an RPA pilot you operate almost entirely under VFR, so these two charts — together with the NOTAM system covered in Section 6.4 — are the foundation of legal route planning.

VTC — Visual Terminal Chart

A VTC covers the vicinity of major aerodromes and their terminal areas. It is the chart you reach for whenever an operation sits near a capital-city aerodrome or a busy regional towered field. Key characteristics:

• Scale: approximately 1:250,000 — the most detailed of the two visual series. At this scale, 1 cm on the chart represents about 2.5 km on the ground, which is fine enough to resolve individual control-zone steps, CTAF rings, and clusters of obstacles near a field.
• Coverage: a defined terminal area around one or more major aerodromes (for example, the Sydney, Melbourne, Brisbane, Perth, Adelaide, and Gold Coast terminal areas, plus major regional towers).
• Depicts: airspace classes and boundaries, Control Zones (CTR), Control Area (CTA) steps, Common Traffic Advisory Frequency (CTAF) areas, restricted/danger/prohibited areas, obstacles (towers, masts, powerlines) with elevations, significant terrain, and hazards.
• Use case: planning operations within or near a terminal area where precise airspace boundaries and obstacle densities matter.

VNC — Visual Navigation Chart

A VNC covers the broader areas between VTCs. When an operation is outside a terminal area, the VNC is the appropriate chart.

• Scale: 1:500,000 — less terminal-area detail but wider coverage. At this scale, 1 cm represents about 5 km, sufficient for regional route planning but coarse enough that you should switch to the VTC when approaching a terminal area.
• Coverage: regional and remote areas not served by a VTC.
• Depicts: the same family of information as the VTC (airspace classes, CTA steps, CTAF, restricted/danger/prohibited areas, obstacles, terrain) at a coarser resolution.
• Use case: cross-country or regional RPA operations away from major aerodromes.

Reading Elevations: AMSL versus AGL

The single most important habit on any visual chart is distinguishing AMSL (above mean sea level, sometimes labelled ALT) from AGL (above ground level). Charted airspace bases, obstacle heights, and terrain elevations are published in AMSL. RPA standard operating height limits, however, are expressed in AGL — the CASA standard limit is 120 m (approximately 400 ft) AGL unless otherwise approved. Mixing the two is one of the most common planning errors and can put an RPA inside controlled airspace without the pilot realising it.

To compare an RPA height limit with a charted airspace base you must first convert one to the other using the charted ground elevation:

Airspace base (AMSL) − Ground elevation (AMSL) = Airspace base (AGL)

Ground elevation is read from the chart's contour and spot-height layer. VTCs and VNCs show relief using a combination of contour lines (lines of constant elevation, drawn at fixed intervals), spot heights (individual point elevations marked with a dot and a figure), and layer tinting or hypsometric shading that gives higher ground a distinct colour. Where the operating site sits on a slope, read the nearest contour or spot height that bounds the site — do not interpolate across a wide valley. Where terrain varies across the operating area, use the highest ground elevation under the planned flight to give the most conservative (lowest) AGL airspace base.

Worked Example

Suppose the chart shows a CTA base of 1,200 ft AMSL over terrain charted at 600 ft AMSL.

1. Subtract the ground elevation from the airspace base: 1,200 − 600 = 600 ft AGL. That is the controlled airspace base above the ground at that point.
2. Your RPA flight at the standard 120 m (≈400 ft) AGL sits at roughly 1,000 ft AMSL (600 ft terrain + 400 ft AGL).
3. 1,000 ft AMSL is below the 1,200 ft AMSL CTA base, so the flight is below the CTA step at that location.
4. This does not by itself clear the flight — you must also check whether the point sits inside a Control Zone (CTR), which is controlled airspace from the surface up to its boundary. Inside a CTR, the CTA base is irrelevant because the controlled airspace already reaches the ground.

If the same CTA base sat over 900 ft AMSL terrain instead, the AGL base would be only 300 ft — below your 400 ft AGL operating height — and the standard flight would enter controlled airspace. Same charted step, different terrain, opposite result. That is why the conversion must be done at the operating point, not read off the step label alone.

Symbols You Must Recognise

• Airspace class boundaries: solid and dashed lines with the class letter (G, D, C) annotated along the boundary.
• CTA steps: stepped lines with the base altitude in feet AMSL printed along each segment; each step's base applies from that line outward until the next step.
• CTR (Control Zone): a boundary enclosing a towered aerodrome, surface to its upper limit.
• CTAF: a dashed circle around a non-towered aerodrome with the frequency printed in a small frequency box; the number is the frequency you broadcast on to coordinate with other traffic, not an ATC clearance frequency.
• Restricted, danger, and prohibited areas: hatched or dotted areas with an identifier (e.g., RA3, D, P) and activation details; the identifier tells you the tier, the activation note tells you when it applies.
• Obstacles: towers, masts, and powerlines marked with a symbol and an elevation in feet AMSL; group obstacles may carry a grouped elevation. Lit obstacles carry a dedicated light symbol.
• Aerodromes: towered fields show a controlled-aerodrome symbol with the tower frequency; non-towered fields show a CTAF symbol and frequency.

The CTAF Frequency Box

Around each non-towered aerodrome the chart prints a CTAF frequency box — the Common Traffic Advisory Frequency on which pilots self-broadcast position and intentions. For an RPA pilot operating near a non-towered field, this box tells you two things: the frequency to monitor (and, where your aircraft is equipped, to broadcast on), and the lateral extent of the CTAF area within which you should be making calls. Broadcasting on CTAF is not an ATC clearance — it is collision-avoidance coordination with other traffic.

Chart Edition and Currency

Every VTC and VNC prints an edition date in the chart margin. Airservices publishes new editions on a regular cycle, and between editions changes are promulgated by NOTAM and the AIP. Before planning, check the edition date against the current edition published by Airservices; a superseded chart may show CTA steps, restricted areas, or obstacles that have since changed. Using the current edition is part of the pre-flight workflow described in Section 6.4 — it is not optional.

Key habit: every height on a VTC or VNC is AMSL unless explicitly marked AGL. Convert at the operating point using the highest charted ground elevation under the flight, and confirm the chart edition is current before you plan.