Overhead join
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An overhead join is a conventional method for an aircraft to integrate with the air traffic pattern near an airfield, join the circuit and land.
Aircraft may arrive at the landing site from any direction, so a safe means of integrating into existing traffic and aligning with the runway is required. The overhead join is the standard method used in the UK, South Africa and other Commonwealth countries at smaller airports by general aviation aircraft flying under the Visual Flight Rules.
Prior to arrival, the pilot will liaise with air traffic control over the radio to establish the runway in use, the circuit height and direction (left or right hand), the QFE of the field. If the airfield is not equipped with ATC or radio, he will need to establish these things before arrival by contacting the airfield prior to departure.
This information is verified on arrival by overflying the airfield and looking out for the wind direction (from a wind sock), any ground signals in the signals square (if present). This involves positioning the aircraft so that it is flying across the direction of the runway but usually at 2000 feet above ground level (AGL). He overflies the runway, looking out for other traffic in the circuit, and descends to circuit height (usually 1000 feet AGL) on the dead side (opposite that of the circuit). With no traffic to affect, he will join the circuit by crossing the upwind threshold and then turning downwind. With other traffic present in the circuit, he can position himself downwind in the circuit behind or between other traffic, and land in turn.
Alternatives to the overhead join are to directly join the circuit by entering at a suitable corner, or a straight-in approach. If available, ATC and the pilot will negotiate which is the most appropriate method according to the current traffic situation.