Overhead join
Encyclopedia
An overhead join is a conventional method for an aircraft
to approach and safely land at an airfield. It helps a pilot to integrate with any air traffic pattern near an airfield, join any 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
, and especially at airfields with no regular radio service.
Prior to arrival, the pilot might talk with air traffic control
over the radio to establish the runway in use, the circuit height and direction (left or right hand), and the QFE (atmospheric pressure) of the field. If the airfield is not equipped with ATC or radio, the pilot will establish these things before arrival by contacting the airfield prior to departure, or by using weather forecasts and the like.
This information is verified on arrival by overflying the airfield and looking out for the wind direction indications from a wind sock, smoke from fires, etc., or 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 and typically at 1000 feet above the circuit pattern for the airfield.
The pilot crosses the runway from the normal circuit for that runway, looking out for other traffic in the circuit, and descends to circuit height (often 1000 feet AGL
for heavier GA aircraft or 500–600 feet for light aircraft and microlights) on the dead side (opposite that of the normal circuit). With no traffic in circuit, the circuit is joined by crossing the upwind threshold and then turning downwind. With other traffic present in the circuit, the aircraft might be positioned downwind in the circuit behind or between other traffic in order to 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 will negotiate with the pilot which is the most appropriate method according to the current traffic situation.
Standard Overhead Join poster reference
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...
to approach and safely land at an airfield. It helps a pilot to integrate with any air traffic pattern near an airfield, join any 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
Runway
According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...
is required. The overhead join is the standard method used in the UK, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
and other Commonwealth
Commonwealth of Nations
The Commonwealth of Nations, normally referred to as the Commonwealth and formerly known as the British Commonwealth, is an intergovernmental organisation of fifty-four independent member states...
countries at smaller airports by general aviation
General aviation
General aviation is one of the two categories of civil aviation. It refers to all flights other than military and scheduled airline and regular cargo flights, both private and commercial. General aviation flights range from gliders and powered parachutes to large, non-scheduled cargo jet flights...
aircraft flying under the Visual Flight Rules
Visual flight rules
Visual flight rules are a set of regulations which allow a pilot to operate an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Specifically, the weather must be better than basic VFR weather minimums, as specified in the rules of the...
, and especially at airfields with no regular radio service.
Prior to arrival, the pilot might talk with air traffic control
Air traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...
over the radio to establish the runway in use, the circuit height and direction (left or right hand), and the QFE (atmospheric pressure) of the field. If the airfield is not equipped with ATC or radio, the pilot will establish these things before arrival by contacting the airfield prior to departure, or by using weather forecasts and the like.
This information is verified on arrival by overflying the airfield and looking out for the wind direction indications from a wind sock, smoke from fires, etc., or 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 and typically at 1000 feet above the circuit pattern for the airfield.
The pilot crosses the runway from the normal circuit for that runway, looking out for other traffic in the circuit, and descends to circuit height (often 1000 feet AGL
AGL
AGL may refer to:* A Graphics Language, a high level language to control early HP plotters* Abergele and Pensarn railway station, United Kingdom, from its National Rail code* Above ground level, in aviation* Adobe Glyph List...
for heavier GA aircraft or 500–600 feet for light aircraft and microlights) on the dead side (opposite that of the normal circuit). With no traffic in circuit, the circuit is joined by crossing the upwind threshold and then turning downwind. With other traffic present in the circuit, the aircraft might be positioned downwind in the circuit behind or between other traffic in order to 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 will negotiate with the pilot which is the most appropriate method according to the current traffic situation.
See also
Standard Overhead Jpin 3-D diagramStandard Overhead Join poster reference