Approach Control

A holding clearance defines where to wait, at what level, in what pattern and until what planning time. Every component matters because a missing fix, track or turn direction can create a completely different flight path.

Three forms of holding

For visual holding, ATC may say HOLD VISUAL OVER a position or HOLD VISUAL BETWEEN two prominent landmarks. Over a published facility or fix, the phrase is CLEARED TO or PROCEED TO the fix, MAINTAIN, CLIMB TO or DESCEND TO the level, then HOLD direction AS PUBLISHED, followed by an expected approach or further clearance time.

When no published pattern is suitable, the full clearance states the fix, level, radial or inbound track, right or left hand turns, outbound time in minutes, and the time to expect approach clearance or further clearance. A VOR/DME hold may replace outbound time with a limiting DME distance.

Expected times

Worked published hold

Approach speed and missed approach planning

Approach may use MAINTAIN (number) KNOTS, REDUCE SPEED TO (number) KNOTS, REDUCE TO MINIMUM APPROACH SPEED, RESUME NORMAL SPEED or NO ATC SPEED RESTRICTION. A speed instruction does not cancel configuration or safety limits. Before the approach, ATC may brief IN THE EVENT OF GO AROUND followed by a heading, level, route or holding instruction. The crew reads it back and retains it for a missed approach unless a published procedure or later instruction applies.

Radar can position an aircraft for a pilot-interpreted approach or provide the approach guidance itself. Keep the distinction clear: vectors lead to an aid, SRA supplies surveillance guidance and PAR supplies precise azimuth and elevation talkdown.

Vectors to final

If a vector will cross the localiser for spacing, ATC warns EXPECT VECTOR ACROSS LOCALISER, THIS TURN WILL TAKE YOU THROUGH LOCALISER or TAKING YOU THROUGH LOCALISER, with the reason. For parallel approaches ATC may specify runway left or right, correct an aircraft that has crossed the localiser and give immediate avoiding action for an aircraft penetrating the no transgression zone. Below 400 feet above threshold, an urgent climb may be issued to avoid traffic deviating from the adjacent approach.

Surveillance radar approach

Before an SRA, ATC states the runway, where guidance terminates, obstacle clearance altitude and what to do after a go-around. The phraseology includes THIS WILL BE A SURVEILLANCE RADAR APPROACH RUNWAY (number), APPROACH INSTRUCTIONS WILL BE TERMINATED AT (distance) FROM TOUCHDOWN, COMMENCE DESCENT NOW TO MAINTAIN A (number) DEGREE GLIDE PATH, and at each check (distance) FROM TOUCHDOWN, ALTITUDE SHOULD BE (number).

Position calls continue toward touchdown. Near final, ATC says CHECK GEAR DOWN AND LOCKED, then DO NOT ACKNOWLEDGE FURTHER TRANSMISSIONS so the talkdown is not interrupted. Completion phrases include REPORT VISUAL, REPORT RUNWAY LIGHTS IN SIGHT and APPROACH COMPLETED CONTACT TOWER.

Precision approach radar

PAR gives continuous azimuth and elevation guidance. The controller keeps the aircraft on the centre line with CLOSING FROM THE LEFT, CLOSING FROM THE RIGHT, ON TRACK, TURN LEFT or TURN RIGHT. Vertical guidance uses ON GLIDE PATH, SLIGHTLY ABOVE GLIDE PATH, ABOVE GLIDE PATH, SLIGHTLY BELOW GLIDE PATH, BELOW GLIDE PATH and COMING BACK TO THE GLIDE PATH. Distance calls, gear check and the no-acknowledgement instruction complete the talkdown.

A good handoff lets the next controller identify the flight, understand the clearance already in force and issue the next safe descent, approach or zone instruction without rebuilding the traffic picture.

Initial contact with Approach

An arriving IFR aircraft normally receives descent to a clearance limit from Area Control before transfer. On first contact give the station called, full callsign, aircraft type and wake category when relevant, position or DME and radial, level, estimate, ATIS code and request. The controller may instruct SQUAWK a code or SQUAWK IDENT, then report IDENTIFIED or RADAR CONTACT with position. Read back any code, level, QNH, transition level, heading and approach clearance.

IFR departure handoff

On first contact with the en route ATS unit, an IFR departure includes callsign, SID or departure designator when applicable, current or passing level, and the initial climb level. The crew also reports any heading or speed instruction still in force. Departure instructions may be issued by radar or procedural control.

VFR arrivals and departures

A VFR arrival may have to contact Approach before entering its area or a control zone. Acknowledge ATIS when available; otherwise Approach passes aerodrome data. Traffic information helps the pilot maintain own separation. A VFR departure should report leaving the Approach unit's area when required.

Further handoff examples

Special VFR

Special VFR is issued only for flight within a control zone, normally at pilot request. The pilot complies with ATC instructions, remains clear of cloud and in sight of the surface, stays within licence limitations, observes low flying restrictions and avoids other aerodrome traffic zones unless permission has been obtained. The clearance contains specific instructions to leave the zone.

Approach phraseology identifies who supplies the guidance. ILS, VOR, NDB and RNAV are pilot-interpreted; SRA and PAR guidance comes from the controller. The clearance never removes the crew's duty to monitor the correct procedure and minima.

NDB and VOR procedures

NDB and VOR instrument approaches are published, pilot-interpreted procedures. Their tracks are defined by NDB bearings or VOR radials, and some use marker beacons or DME for range. An aircraft may also receive radar vectors to the final track. Report procedure milestones such as entering the hold, beacon outbound, base turn complete, a stated DME and visual contact.

RNAV and RNP GNSS

Suitably equipped aircraft may fly RNAV GNSS SIDs, STARs and approaches. A SID clearance normally comes from Clearance Delivery before pushback or start. A transition can connect the SID to the en route system. A STAR chart normally contains a transition route from an ATS route waypoint and an arrival route that positions the aircraft for approach.

Request an RNAV GNSS instrument approach by its initial approach fix and runway designator. If ATC knows of GNSS problems, it states the type of operation affected, location, geographical limits and times. A RAIM ALERT means Receiver Autonomous Integrity Monitoring cannot assure the navigation solution, commonly because too few satellites are in view or a system fault exists. Discontinue the affected approach as required and tell ATC the event and intentions.

Procedure requests and reports

RNAV SID and STAR examples

DME arc approach

On an ILS/DME approach using a DME arc, reports identify the joining radial, DME fix, level, lead radial, inbound radial, localiser capture, glide-path intercept and outer marker. Each report lets Approach check that the aircraft is at the correct part of the procedure.

VHF direction finding lets a ground station derive a bearing from the aircraft's transmission. The pilot requests the required bearing, transmits for a sufficient period and reads back the value together with its accuracy class.

Bearing and position accuracy

Direction-finding Q codes

End each aircraft transmission with its callsign. The station replies with the code or plain-language bearing, degrees relative to the direction-finding station, the class and, when needed, observation time.

Series of homings and pilot-interpreted VDF

For a series, request QDL or repeated QDM or QTE. Early in a VDF homing, QDM requests are often about one minute apart and become more frequent near the overhead. The pilot uses the series to establish the prescribed track. The VDF procedure is fully pilot-interpreted. At the overhead, time the outbound leg, use bearings to maintain the outbound track, descend as notified and turn onto the final approach QDM. If visual contact is not achieved at the missed approach point, normally the VDF overhead, go around.

Timed QDM series and loss of bearing

The complete arrival is a chain of clearances and reports. The following exchanges preserve the book's sequence from initial call, through descent or holding, to approach capture and transfer to Tower.

VOR/NDB procedure followed by ILS

Straight-in ILS with delay absorption

VOR approach and DME arc milestones

Worked beacon approach

Visual approach and transfer

Outer marker to landing clearance