Life In The Tower

Mr Smith states that he is of the opinion that it is generally agreed by those persons who took part in the study, that the Americans are making much better use of their runways and airspace than we do here in Australia.

Basically, the purpose of the trip was to examine usage of parallel-runways at the main international Airports.

Mr Bill Adams stated on his return that the U. S. system of Air Traffic Control has a flexibility which the Australian system lacks. He further stated that from a VFR pilot’s outlook, the U. S. system of ATC is safer, with VFR aircraft not crowded into low level corridors, which potentially have a high-terrain confliction problem.

Mr Adams observed that U. S. pilots flying both IFR and VFR can be radar-separated if the VFR pilot indicates to ATC that he wishes to avail himself of the service. VFR aircraft are permitted to overfly Terminal Control Areas at San Francisco at an altitude of 8000 feet, without making a radio call relating to the intended track of the aircraft, and San Diego and Los Angeles have similar VFR corridors over their International Airports.

Mr Adams also observed the lack of a priority system for U. S. pilots. The U. S. system is basically one of first-come-first served, with heavy jets being slotted behind small Cessna aircraft if the ‘heavies’ arrive second in the queue.

Mr Adams states that in the Los Angeles area alone, there are 19 airports. From observations made at the ATC centres in the U. S. , the controllers are trained to have a different attitude to separation than here. Mr Adams winces slightly when he tells of private pilots in Australia being positioned last in the queue every time when they are competing for arrival slots with RPT aircraft.

In relation to U. S. wake-turbulence standards, Mr Adams says that the corresponding Australian standards are too great, and should be more flexible when smaller jet aircraft are involved. In the U. S. , wake-turbulence separation is in many cases left to the discretion of the pilots, and he adds that out of 4023 aircraft accidents in the U. S. during 1979, none were due to wake-turbulence.

He sees the answers to some of Sydney Airport’s problems as being a short close-spaced runway, adjacent to runways 16-34, built on Commonwealth property, that is already part of the airport perimeter. He states that at the present time, fifty-four per cent of all traffic at Sydney is General Aviation. The inference taken by me is that General Aviation aircraft should be treated better by ATC.

Bearing all these points in mind, the ability of U. S. controllers to handle more traffic in a varying fashion to that employed in Australia is a direct result of some of the advanced equipment available to them, namely the very decided advantage of altitude and speed-encoded radar interrogation. This equipment is only currently used in Australia at Adelaide Airport. Australian controllers at all other primary airports still play their brand of three-dimensional chess with outdated 1950s-style radar interrogation equipment, juggling heights, speeds, and positions; making only the right decisions, in a quietly professional manner.

Given the new radar mode, the situation here would be quite different, and in Sydney, given another runway, local traffic handling techniques would be revitalised. Sydney Airport is often reduced to the usage of one runway, such as runway 16, in unfavourable wind conditions. In peak times, all arriving and departing aircraft have to be radar-vectored for one runway which must cause a gigantic aerial traffic jam.

Figures recently made available by the Department of Aviation report that twelve million dollars per annum is being blown on wasted fuel by aircraft using Sydney Airport, alone! By 1987 the expenditure caused by traffic delays is expected to reach thirty-two million dollars. How can commercial airlines be profitable in this environment?

In off-peak times, International and Domestic airliners must carry extra fuel enabling 20 minutes of holding, and this requirement is doubled and tripled for other more busy periods during the day, particularly when one runway only is in use. Commuter airlines and those aircraft plying charter work are expected to have an extra 40 minutes’ fuel in off-peak times, extending to 80 minutes in peak-traffic-congestion periods.

The Department of Aviation released these figures in an Information Paper, directed at Local Government Councils, located in areas adjoining Sydney International Airport, and its main flight-approach paths. The Department has suggested eleven remedies for the delay troubles now constituting an expensive headache for the airlines using the airport.

Some options being examined include making amendments to the 11 p. m. to 6 a. m. curfew for jet operations, and making greater use of intersection departures on runways 16-34, the main north-south runways. Landing aircraft would be mainly accommodated on runways 07-25, uninterrupted by the use of the southern-most part of the main north-south runway 16. ‘Stubbie’ runway usage is not new at Sydney, as runway 07 intersection departures have been used for some time now for light or for STOL aircraft. Obviously, at Sydney, a new runway is the only real answer, along with other measures, including the removal of unnecessary traffic from Sydney, and perhaps . . . don’t hold your breath . . . a second International Airport. While the residents of Sydney clearly want to use its airport and facilities, they appear not to want the airport in their own backyard.

One Commuter Airline operator complained to me recently about ATC holding delays south-west of Sydney, but controllers are so saturated with traffic in this area in peak times, one aircraft is on approach every five miles, or two minutes. That’s about as close as they can safely position them.

Even in the U. S. A. , with the newer height/speed-encoded S. S. R. transponder equipment, they only have slightly less space between arriving aircraft, a minimum of four miles. It strikes me as harsh to expect more of the controllers we now have operating the antiquated 1950s equipment in everyday usage. Lack of funds has ruled out the early introduction of height-encoded radar equipment. Each separate radar console operated by individual workface controllers costs thirty-eight thousand dollars. Adelaide Airport is the only centre to have this new equipment operational at the present time, with Perth Airport being earmarked for its installation as soon as funds and technical manpower permit. Sydney Airport is apparently the lowest on the list of priorities.

The Air Traffic Controllers workforce is seriously undermanned; there is a shortage of between 100 and 200 controllers needed to make up the number of workforce radar positions to adequately cope with Australia’s increasing air traffic problem.

Gregg Daven, a young Grade 5 Air Traffic Controller at Sydney Area Approach Control Centre makes his way into the softly lit radar room. It’s 12. 45 p. m. and Gregg commences his seven-hour shift as an Approach-Departures controller in fifteen minutes. Following some light banter with colleagues, and the S. T. A. C. (Senior Terminal Area Controller), Gregg takes up a position firstly at the Procedural Control console, working next to the Flow-Controller.

Gregg’s now 34. He entered the training school for controllers in Melbourne in January 1972, and graduated exactly two years later. He checks on his headset the latest ATIS information for Sydney Airport. Information Kilo is current. Runway 16 Departures, Runway 16 or 07 Arrivals, wind is light and variable, and downwind 4. QNH is 1019, temperature 17, rain in the area.

Mounted in front of Gregg, in special holders, on flight strips, are numerous abbreviated aircraft flight plans, each coloured according to the category in which they are to be placed. Yellow is for inbound traffic, blue for outbound, and pink is for crossing traffic. The flight-strips are holding information on aircraft in the air, and some are still not airborne. We look them over, and see some familiar callsigns. VH-TBH, TAA’s Boeing 727, VH-ANA, Ansell’s long-range 727, VH-FCB, an Ansett (now Air New South Wales) Fokker Friendship and VH-ATE, the Fokker Fellowship belonging to the Department of Aviation. In addition, there are strips for other well-known aircraft, VH-KIR, Aussie Trojan 762 (a Hercules), VH-WAD, KNO, RVS, FLN, Navy 860 (a Skyhawk A-4G), and Navy 880. Then there’s VH-CZN (an Ansett Boeing 737), VH-FCC, KZQ, along with three heavy jets, Qantas 65, a Boeing 747-SP-38, New Zealand 114 (a DC-10), and Nuigini 1 (a Boeing 707). The flight-strips are completed with East-West 169, a Fokker Friendship tracking Norfolk for Sydney.

It’s now 2. 25 p. m. Gregg is still working Procedural Control, giving details to Sector 8 and Sector 6 Airways Controllers on Aussie Trojan 762, which is not yet off the ground, bound from a strip near the Singleton Army camp, for Mangalore, via Katoomba, Rugby and Wagga. Two RAAF controllers work in uniform alongside the civilian ATC staff at Sydney’s Area Approach Control centre, but even so, with such first-hand liaison available, military aviation constitutes an ongoing major headache for civilian air traffic controllers. The situation is that the military aircraft have to be slotted in, clear of the civil movements, and that’s not too easy a task in times of high controller workload. If military aircraft are exercising and NOTAMs have been issued, civil aircraft have to be vectored around, or underneath the military aircraft.

2. 45 p. m. , and Martin, who is controlling Arrivals South and North on frequencies of 123. 4 and 129. 8 Mhz, just to the right of the Procedural console, is arranging small plastic ‘shrimp-boats’ representing VH-KNO, and KZO, which will be affixed to the radar screen for aircraft identification purposes. Martin has only just taken over from Gary, who has been relieved so he can take a short break. There are no substantial breaks in the Area Approach Control centre. A controller may be able to be relieved while he grabs a cigarette or a cup of coffee, but that is all he will get during his shift. Even the system of short breaks depends on the availability of a man to sit in for the controller while he takes his few minutes away from the screen. Controllers work sevenhour shifts, and while some shifts are purposely over-lapped to enable the taking of work breaks, the situation does not happen enough to allow everyone to take a break from the workforce screen.

At the present time, there are 30 personnel in the Area Approach Control centre. Romeo Mike Papa is calling Martin. Martin requests VH-RMP to ‘squawk-ident’, and a familiar geometric symbol manifests itself around the radar ‘paint’, which represents the Boeing 727 of Ansett Airlines. 2. 50 p. m. , and a quick look at the radar screens in the centre reveals as many as eleven aircraft being controlled by an individual controller. VH-UTL, a helicopter, is lifting off from Palm Beach for Channel 10, and Gregg takes down details from the Sydney Flight Service room. VH-ATE is Singleton at 0505 Zulu (3. 05 p. m. ). The F-28 is tracking Coffs Harbour to Richmond and estimates Richmond 0517 Zulu. Gregg has a short period where is he able to speak to me, the first chance he has had to speak to me since he started his shift almost three hours ago, and we discuss the problem of holding delays.

In peak times, he tells me, considered to be between 3. 00 p. m. and 10. 30 p. m. , normal holding requirements for R. P. T. aircraft is 30 minutes, and for others 60 minutes. The decision on runway usage is made by the Senior Tower Controller (Aerodrome Controller) and the S. T. A. C. (Senior Terminal Area Controller). It’s 3. 00 p. m. , and Gary has been back working Arrivals-south, while Martin has been controlling arriving traffic from the north. The ‘Sydney Control’ frequency which was transceiving on two frequencies 123. 4 and 129. 8 Mhz, has been split, due to workload, and each frequency now has its own controller.

All the consoles are equipped not only with civil VHF frequencies but also include UHF for the benefit of military aircraft.

Gary sat next to Martin, getting the ‘picture’ for about ten minutes prior to his taking over of the Arrivals-south console. The changeover from one to two-man operation of the frequencies involved the quick replacement of ‘shrimp-boats’ representing arriving aircraft from one radar screen to the screen adjacent. The whole operation was handled speedily, efficiently, and quietly.

At 3. 05 p. m. , on Arrivals-South, Foxtrot Charlie Bravo and Charlie Zulu Whiskey are the only aircraft under Gary’s control. The former is an Air New South Wales F-27, while CZW is another Ansett Boeing 737.

Martin, by contrast, has seven aircraft under his control. Gregg is constantly liaising with the Flow controller to ensure no speed control is required. Arrival controllers will occasionally call out a speed of an arriving aircraft for the Flow controller so that the Flow controller can correctly position the aircraft in the approach sequence. Both procedures controllers, and the Flow controller, do not work on radar, although the Flow controller has one before him for monitoring purposes.

At 3. 12 p. m. , Bankstown Tower checks the requirements for VH-ELT, at the time on the ground at Bankstown, and trying to get a clearance into Sydney. Bankstown is told by Gregg that VH-ELT will have to wait until 0540 Zulu (3. 40 p. m. ) before it can take off from Bankstown. The expected landing time is 0554 Zulu, or 3. 54 p. m. Holding delays have now commenced in earnest.

At 3. 15 p. m. , on Arrivals-south, Pan American ‘Clipper 812’ is eight miles ahead of VH-FCB, with Aussie Trojan 762 to the north of them. Not yet on the screen, but expected soon, is VH-BRX and EWT, an East-West F-27.

Information ‘Mike’ is now current. Runway 16 Departures, Runway 16 and 07 Arrivals. Wet. Wind 2-niner-zero degrees at 8 knots. Downwind 5. QNH 1019. Temperature 15. Cloud, 2 oktas . . . 4000 feet, rain in the area, ‘On first contact with Sydney Ground or Approach, notify receipt of Mike. . . ‘

3. 25 p. m. , and Arrivals-north has 3 aircraft under its control, with a corresponding number on Arrivals-south. Gregg and Ron, another controller, conduct a short conversation about a recent television documentary. Gregg is now doing Procedural work on VH-FLN, FCE, ZEU and KGN. At 3. 45 p. m. , the ATIS changes to ‘November’. Runway 16 Departure, 16 or 07 Arrivals. Wind light and variable, downwind 3, QNH 1019, temperature 15, rain in the area.

Soon after, a glance at the flight strips for Departures and Arrivals, north and south, shows that the aircraft being handled at the time are VH-KGN, Wisdom 816 (a BAe-748), VH-TMR, MCQ, MNS, DMV, CJQ, Stallion 741 (an Orion), VH-URT, TJL, and Aussie 769. From the west, there is VH-TBO, ANA, MVB, DTV, SDG, ICB, KZP, and Navy 860, all being channelled into the system, dependent on their respective destinations. In the east, well out over water, Qantas 44, from Auckland, and New Zealand 114, a DC-10, Perth direct Auckland constitute the Oceanic traffic. Another ‘heavy’, Nuigini 1, a Boeing 707, is tracking into Sydney from the north.

I notice three female ATC staff carrying out duties at the far end of the radar room. At 3. 58 p. m. , Ron identifies VH-Romeo Mike Kilo to the southern Approach controller, by using a visual display symbol, which is activated on the radar screen manually. By pressing the intercom button, and linking his position with the Approach controller, the Arrivals controller manually operates the visual symbol on his own screen over the aircraft he wishes to identify, and this is duplicated on the screen before the Approach controller, directly identifying the aircraft for purposes of frequency changeover.

At 4. 40 p. m. , Gregg takes a break. Five to eight minutes later, the break ends. Gregg has not even had a cup of coffee, he has merely had time to step into a recreation room, and have a brief chat about the activities of the past few hours. As in all major world Air Traffic Control centres, the recreation room contains amusement machines and Space Invaders, to allow controllers the opportunity to ‘wind-down’ during their brief periods off workforce duty. The only problem, I’m told, is that during shifts, the machines are not used a great deal, due to the inability of the controllers to avail themselves of realistic meal breaks.

At 4. 47 p. m. , Gregg’s break has officially concluded, and he checks with the S. T. A. C. as to where he will work, and is allocated a workforce position, on Departures-south, on a frequency of 125. 3 Mhz. Immediately, VH-FJZ and MYQ call, with MYQ just leaving 6000 feet. Gregg doesn’t answer, as he is still familiarising himself with the radar ‘picture’. The outgoing controller handles the calls. His name is Chris. Chris advises VH-ARQ and MYQ to call ‘Sydney Control’, on 131. 3 Mhz.

‘Sydney Departures, Alpha Mike Bravo, climbing to seven thousand. ‘ Chris answers, ‘Alpha Mike Bravo, departures, identified. ‘

The Approach-Departures area of the room consists of consoles for Departures-north, adjacent to Departures-south, with Approach-south, and Approach-north immediately to their right. At ninety degrees to these consoles is a desk manned by the Flow controller, with Procedural control immediately adjacent/to the right of the Flow console, and then in succession, Arrivals-south, and Arrivals-north.

In addition to these consoles, there are numerous sector control consoles, equipped with radar, for the ‘airways’ linking the major capital cities, and those that are the tracks followed by overseas-bound aircraft.

The radar equipment used by Air Traffic controllers at Sydney is simply outdated. Designed for use in the late 1950s, thirty-year-old equipment was used successfully in the 1980s purely due to the professionalism of those who are required to operate it. Inadequate, albeit workable accessories come hand-in-hand with the old radar. A milk bottle, half full of cleansing water for the radar-screen shrimp-boat markers is placed on the Approach-Departures workforce console.

Gregg is now operational. It is 5 p. m. , and a young ATC trainee dumps a pile of fresh plastic flight-strip holders into a receptacle on the left-hand side of Gregg’s chair, near the floor. The receptacle resembles a drawer, and is built into the console, A colleague speaks briefly to Gregg about the cover at Jindabyne over the past few days,

‘Mike Xray Yankee, call control on 131 decimal 3. ‘ The aircraft repeats its own callsign by way of acknowledgement. Little bells constantly ring, indicating a controller at one position wishes to speak a colleague on the intercom system, a refined telephone link that obviates the need for any controller to leave his seat to converse with a controller at any other position in the room,

‘Sydney Departures, Alpha Mike Quebec climbing to nine thousand, and requesting onward clearance. ‘ Gregg quickly deals with the departing air ambulance. Soon after, he is called by VH-ESV, turning left to join the 195-degree radial, climbing to 5000 feet. ‘Echo Sierra Victor, departures, identified,’

An approach controller with a few seconds to spare and a sense of humour leans over to enquire how much sex content is going to be included in the story I’m writing. He states emphatically that he won’t read it unless it has its share of romantic interest. He is interrupted by Nuigini 1. ‘Sydney Approach, Nuigini one, with you, with information Papa. ‘

Sydney Terminal Information Papa, Runway 16 Departures, Runway 16 or 07 Arrivals. Wind, light and variable, downwind 2, QNH 1019, temperature 13, CAVOK. (CAVOK means cloud ceiling and visibility are better than prescribed values or conditions. )

Gregg prefers to work using a headset equipped with a lightweight boom microphone, as do most of the workforce personnel, at least in peak traffic times. The alternative is an Ericofon handset, and this is simply picked up and replaced in front of the controller on his console.

VH-RMK, an Ansett 727, calls leaving 6000 feet. He is acknowledged, and then VH-FDD advises he is climbing to 3000 feet. ‘Foxtrot Delta Delta, squawk-ident. Romeo Mike Kilo, call control, on 125 decimal 6. Foxtrot Delta Delta, climb to six-five zero-zero, report leaving 3000. ‘ At 5. 13 p. m. , the pressure is really on. The room in which ATC is housed is a wood-panelled, carpeted, acoustically-pleasant area containing an atmosphere of busy efficiency, with the professionals who work there maintaining an ‘All-OK’ attitude.

A Japan Airlines poster is mounted on the wall above the Approach-Departures consoles, directly underneath a ‘no smoking’ symbol. ‘Foxtrot Delta Delta, call control on 131 decimal 3, good evening. ‘ Foxtrot Delta Delta replies, and adds a courteous ‘Good night sir. ‘

‘Echo Sierra Victor, contact departures on 123 decimal zero. ‘

As I look around, controllers right around the room are continually marking up new ‘shrimp-boats’ and replacing the plastic flight-strip holders that have been used and are no longer required into the receptacle built into their console.

It’s 5. 30 p. m. , and the Approach-south controller complains to the S. T. A. C. about a radio breakthrough from TAA’s company operated on 129. 5 Mhz. The frequency being interfered with is 127. 0 Mhz. The S. T. A. C. asks whether the interference is bad enough to warrant action immediately, and is met with a light-hearted, but unprintable reply.

At 5. 35 p. m. , VH-DMV is climbing to 6500 feet, and VH-PTH is climbing to 3000 feet. Five minutes later, both these aircraft are being skillfully vectored away from each other, VH-PTH turning left 160 degrees, and VH-DMV reporting level at 6500 feet.

‘Papa Tango Hotel requests direct-track G. N. S. to Moruya,’ and is advised by Gregg at 5. 44 p. m. to call control on 125. 6 Mhz. Shortly after Gregg advises VH-DMV to call control on 131. 3 Mhz. ‘Delta Victor Romeo, report level. . . Delta Victor Romeo, turn right heading 2-8-zero. . . Delta Victor Romeo, turn further right to intercept the 2-7-5 radial . . . Mike Victor Bravo identified. ‘ At 5. 48 p. m. , Qantas flight 44 Auckland for Sydney calls the Approach-north controller. ‘Sydney Approach, Qantas four-four, with information Papa. ‘

‘Qantas four-four, Sydney Approach, good afternoon, descend to five thousand, Runway 16, expected visual left base. ‘

Gregg on Departures-south liaises with the Approach-_south controller to get a turbo-prop aircraft clear of TAA Boeing 727 VH-TBI. At 6. 00 p. m. , only VH-RMO and VH-MZV are on the screen under Gregg’s watchful eye.

At 6. 15 p. m. , the S. T. A. C. decides to give Gregg a turn in the Approach-south radar position, and after his familiarisation period Gregg begins working the frequency 127. 0 Mhz.

Immediately, the channel is busy. ‘Charlie Zulu Quebec, reduce your approach speed as soon as safely practicable, you’re number two to a Friendship, still with ten miles to run on 07. He’s back to 150 knots. . . Charlie Zulu Quebec, what speed can you come to . . . Qantas one-one descend to three thousand . . . Foxtrot Charlie Alpha, your speed now, please. . . Charlie Zulu Quebec, clear for final, the Friendship is seven miles ahead going through one-four-zero knots reducing. . . now you are cleared for final, remain this frequency. . . Foxtrot Charlie Alpha, call tower 120 decimal five. . . Qantas one-one, turn left heading zero-four-zero to widen your circuit, you have three miles to run. Charlie Zulu Quebec, call tower 120 decimal five at the NDB, thank you for your help. ”

Qantas 11 is then requested by Gregg to turn left heading 020 degrees, a short downwind leg, to stretch the sequence out. ‘Qantas one-one, turn right heading zero-six-zero for the square base, expect to continue your turn onto the centre-line, you now have one-seven miles to run. . . Qantas one-one, continue the right-turn heading one-three-zero, for the pilot intercept of the 156 localiser, clear for final, report established. ”

Gregg then notices that the Qantas 747 has gone through the localiser, so he issues instructions for the captain to continue his right turn intercept and advises the aircraft has 14 miles to run to touchdown. ‘

Qantas one-one, reduce back to your approach speed, you’re number three to land, number two’s a Navajo with four miles to run on runway one-six. You now have one-zero miles to run. ‘

Gregg speaks to a colleague in the Tower on the intercom, and also liaises with other Approach and Departure positions . . . ‘ Ah, this is going to be tight, this aircraft’s right back. Qantas has been told about the aircraft in front. He’s coming right back to his approach speed. If he has to go round, runway heading, 3000?’

The go-round procedure is confirmed, if necessary, and someone asks on the interphone, ‘Is it a widebody?’ Gregg simply states ‘747. ‘

‘Qantas one-one, we can’t come back much below 150 knots. ‘ Gregg acknowledges and advises the Captain of OF 11 to call the tower. The Navajo at the time is only 5 miles ahead. As. Closely positioned as these aircraft were, both landed without the need for a go-round by either. An Ansett Friendship calls Gregg with information ‘Papa’. The sound of teleprinters can be heard in the background in the Area Approach Control room. Martin, who is working Arrivals-south 123. 4 Mhz, calls Gregg on the intercom. He notifies of VH-DBU coming into Gregg’s airspace at 5000 feet. Gregg says “Accept Delta Bravo Uniform, thank you,’ and waits for the aircraft to call him. He arranges a ‘shrimpboat’ at the side of the radar screen, ready for VH-DBU.

‘Foxtrot Charlie Bravo, you have one eight miles to run, resume desired speed. Call Tower, 120 decimal five at the NDB . . . any snow down there?’

It went unanswered, as the F-27 was already calling the Tower.

Tango Bravo Juliet, Approach, descend to six thousand, runway 07, expect a straight-in approach, notify descent, report approaching 6000. ‘

VH-DBU, now on Gregg’s frequency, bound for Bankstown, reports. . . ‘ Delta Bravo Uniform, and can’t see 2FC. ‘ Gregg advises the woman in command of VH-DBU ‘Delta Bravo Uniform, Roger, it’s twelve o’clock and four miles. ‘

Approach-north then liaises with Gregg on the intercom regarding Air Van 5, a Boeing 737, direct from Port Vila, Vanuatu, for Sydney who is on a visual left base for runway 16 and may conflict with some of Gregg’s arriving traffic from the south, also being vectored for a 16 Arrival.

It’s now just after 7. 00 p. m. , and the holding required earlier in the afternoon has been eliminated. In busy periods, aircraft may not be able to land straight away, due to congestion, so the efficient method of holding arriving aircraft is used worldwide. Aircraft in holding patterns fly ovular, or ‘racetrack’ patterns above radio beacons, usually 80-50 nautical miles (NM) from the destination airfield. One complete orbit of the VOA is normally made every two minutes. If multiple aircraft are holding over the same radio aid, each aircraft must have its own flight-level or altitude in the pattern, with at least 1000 feet vertical separation between them. In multiple-aircraft holding patterns used in this country, aircraft from any part of the stack may be told to cancel holding and track to the destination airport, but in the United Kingdom and the United States, aircraft from the bottom of the pattern peel off, with those aircraft being held above filling the vacant positions created below, when the holding cancellations are advised. These patterns are very tightly controlled.

In Australia, aircraft hold as high as 26,000 feet (FL260), but in other countries holding is usually carried out up to and including 13,000 feet (FL130).

Overseas holding patterns are usually more numerous than in major Australian centres. Sydney, for example, has two recognised holding patterns, one for northern traffic inbound, and the other for western and southern inbound traffic.

The northern pattern is over Mount McQuoid, marked by a VOR and NOB, and the southern pattern, Bindook, is flown over a VOA (VHF omni-directional radio range). In addition, inbound aircraft from the east flying oceanic sectors are held over water in peak times requiring delay, 65 DME from Sydney, at a position which was once code-named ‘Darter’.

New York, by contrast, has 15 holding patterns. London’s Heathrow has four patterns. As Gregg’s seven-hour shift draws to a close, it may be relevant to mention the London Air Traffic Control Centre at West Drayton (L. A. T. C. C. ).

Controllers at West Drayton monitor the progress by radar of all aircraft in U. K. airspace, that are flying within the London Air Traffic Control Flight-Information Region. North of the London FIR is the Scottish FIR. West Drayton’s Oceanic Control Area extends from near the Dutch coast, to a point just off the Irish south-east coast. All inbound aircraft for Heathrow or Gatwick Airports, that are entering L. A. T. airspace, make contact with Heathrow and Gatwick when about 25-15 nautical miles away from the destination.

L. A. T. C. C. airspace is divided into sectors, either ‘en-route’ or ‘terminal’. Permission to fly from one sector to another must be granted by L. A. T. C. C. before an aircraft may intrude into a new sector.

Inbound aircraft are stacked in holding patterns if they cannot be immediately accommodated on an approach path to the destination airport. Lower levels of the holding patterns are controlled by destination airports, while the higher levels are controlled by terminal sector controllers.

Approximately 80 controllers work on a single shift at West Drayton. This is by contrast with the 30 controllers on a peak time shift at Sydney Airport.

L. A. T. C. C. controllers are divided into five teams, or watches, and in keeping with worldwide regulations hold licences with endorsements similar to pilots. West Drayton controllers train at Bournemouth.

Flight strips at L. A. T. C. C. are computer-generated, not handwritten, as in Sydney. West Drayton’s SSR (secondary surveillance radar) is an advanced equipment that interrogates the aircraft callsign, flight level, and speed of each aircraft under radar control. . . the very same equipment is much needed in Sydney and other major Australian centres now. .

Gregg has been relieved and is thinking about doing $Orne competitive sailing on the weekend. We chat briefly about parallel runways, high-speed runway exits, new radar, and the Department’s proposals for revised usage of the southern part of runway 16. Special thanks are due to Gregg Daven for his kind co-operation on a very busy evening, and to Mr P. S. Langford, Mr John Death, Mr Warwick Bigsworth and Mr Mick Davis for making this most rewarding experience at Sydney’s Area Approach Centre possible.

In the March issue of Australian Aviation, Robert Bell will examine the Study Group Tour of Californian Airports made in 1982 by representatives of DoA, Ansett Airlines, the Australian International Pilots Association, the Aircraft Owners and Pilots Association, the General Aviation community, and the Regional Airlines Association of Australia. The recommendations made as a result of the study tour will be presented in detail, with a view to determining how our ATC system can be upgraded quickly, to cope with the increased demands placed upon it during the eighties!