Free safety module 3 of 7Airspace Classification & Air Traffic Control14 min readLast reviewed: 2026-09-13
Australian airspace classes (A, C, D, E and G), flying VFR beneath controlled-airspace steps, transponder use, and the habits that prevent an unauthorised airspace incursion.
Scenario
VFR Coastal Transit Beneath Melbourne Class C Steps. You are routing VFR southbound along the Port Phillip coastline. The controlled airspace above steps down from 4,500 ft to 2,500 ft, and then to 1,500 ft near a Class D control zone. Air transport arrivals are descending through 3,000 ft in the Class C airspace just above you.
Decisions and actions
Plan to stay clearly below the lower limit of each controlled-airspace step, with a buffer for altimeter and navigation error, unless you hold an ATC clearance.
Altimeter discipline: set the current area QNH. An error of 10 hPa is roughly 300 ft of altitude — enough to put you inside a step.
If your aircraft has a serviceable transponder, it must be active at all times in flight, with Mode C (altitude) operating continuously if fitted (AIP ENR 1.1 para 10.5.1).
Check prohibited, restricted and danger (PRD) areas and their activation times in the Designated Airspace Handbook, ERSA and NOTAMs before you fly.
Safety traps
Climbing into a controlled-airspace step while avoiding terrain, birds or turbulence.
Losing track of position near step boundaries and Class D control zones.
Assuming a filed flight notification is an airspace clearance — it is not.
Check your understanding
1. What are the VMC visibility and cloud-separation minima for a VFR flight in Class C airspace below 10,000 ft AMSL?
5,000 m visibility; 1,500 m horizontally and 1,000 ft vertically clear of cloud
8,000 m visibility; clear of cloud and in sight of ground or water
3,000 m visibility; 600 m horizontally and 500 ft vertically clear of cloud
10 km visibility; 2,000 m horizontally and 1,500 ft vertically clear of cloud
Show answer
A. Below 10,000 ft AMSL in Class C airspace, a VFR aircraft needs 5,000 m flight visibility and must remain 1,500 m horizontally and 1,000 ft vertically clear of cloud.
2. Does filing a flight notification via NAIPS or a flight-planning app give you a clearance to enter Class C or Class D airspace?
Yes — once NAIPS accepts the plan, entry is authorised
No — you must receive an explicit clearance from ATC before entering
Yes, provided the transponder is on and showing altitude
Yes, during daylight VMC hours
Show answer
B. A flight notification is not a clearance. VFR pilots must receive a clearance from the controlling ATC unit before entering Class C or Class D airspace.
Educational use only. This module does not replace current legislation, the AIP, ERSA, authorised weather briefings, the aircraft flight manual or instructor guidance. Verify operational information through official sources before flight.
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