At a non-towered aerodrome the circuit is where aircraft converge. A predictable join, at the right height, on the right side, keeps you where everyone else expects you to be.
Why there is a standard
At a non-towered aerodrome nobody is directing traffic. Everyone in the circuit relies on everyone else flying the same pattern and saying where they are. A standard join lets you arrive without knowing the wind or the runway, and still slot in where others expect you.
Both countries use the same idea: cross the aerodrome above circuit traffic, read the windsock and the traffic, get down to circuit height away from the circuit, then join at a predictable point. The numbers, the names and the radio calls differ.
The one rule that matters most
Never descend from above onto the side of the circuit where the traffic flies. Your own aircraft hides what is below you, and the aircraft below is looking ahead, not up.
AUSTRALIA · NON-TOWERED AERODROME
Overfly join
This example assumes a 1,000 ft circuit, the standard for most piston aircraft such as a C152 or C172. Always check the aerodrome's published circuit height.
1,500 ft+ above the aerodrome
Inbound
Plan to arrive above circuit height. Listen to the CTAF to build a picture of traffic before you get there.
RadioBroadcast inbound by 10 NM, including your ETA.
Used when you are unfamiliar with the aerodrome, or cannot work out the wind, runway or circuit direction before you arrive. Otherwise, join on crosswind, downwind, base or a straight-in approach of not less than 3 NM.
12 questions on joining and flying the circuit in Australia.
Original practice questions, each quoting the clause it is based on.
QUESTION 1 OF 12Australia
You are arriving at a non-controlled aerodrome and cannot work out the wind or circuit direction. Your aircraft's circuit height is 1,000 ft above aerodrome elevation. What is the lowest height you should overfly at?
QUESTION 2 OF 12Australia
After overflying and working out the circuit direction, where should you descend to circuit height?
QUESTION 3 OF 12Australia
Why should you not descend into the active side of the circuit from above?
QUESTION 4 OF 12Australia
AC 91-10 Figure 3 shows a straight-in approach as one way to join the circuit. From how far out should that join begin?
QUESTION 5 OF 12Australia
Regulation 91.360 defines when an aircraft is in the vicinity of a non-controlled aerodrome. Which description matches it?
QUESTION 6 OF 12Australia
A non-controlled aerodrome has an aerodrome reference point published in the authorised aeronautical information. Where is the 10 NM vicinity distance measured from?
QUESTION 7 OF 12Australia
You join the circuit at a non-controlled aerodrome in a C172. The authorised aeronautical information has no instructions on circuit direction. Which way must your circuit turns be?
QUESTION 8 OF 12Australia
The authorised aeronautical information for a non-controlled aerodrome says all circuit turns for runway 27 must be to the right. You are joining for runway 27. What do you do?
QUESTION 9 OF 12Australia
You plan a straight-in approach by day in VMC to a non-controlled aerodrome. You are not using an instrument approach procedure, and your aircraft is not a Part 103 aircraft. Under regulation 91.395, how far from the runway threshold must all your manoeuvring to set up on final be complete?
QUESTION 10 OF 12Australia
You are making a straight-in approach to a non-controlled aerodrome. Under regulation 91.395, who gives way between you and aircraft flying in the circuit?
QUESTION 11 OF 12Australia
Before you start a straight-in approach to a non-controlled aerodrome, what does regulation 91.395 require you to determine?
QUESTION 12 OF 12Australia
You are flying in the vicinity of a non-controlled aerodrome but do not plan to land there. Under regulation 91.375, what must you do about its circuit pattern?
These are not CASA exam questions. Learning only: always check the current AIP and ERSA for the aerodrome you are flying to. Sources and licences