Isle of Man ATC in the 1960s
 
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The New Control Room
The 1960s began with all Air Traffic Control functions operational from the new control room, installed
on the top of the former Royal Navy watch office and giving an uninterrupted view in all directions.
 
New Control Room 1960
 
The new Control Room built on top of the RN Watch Office. BEA Dakota G-AGJZ parked on the apron between the terminal and control tower.
 
With the change to using VHF radio telephony and with cathode ray direction finding available, many of the former support functions required by the old Medium Frequency ATC were no longer required and the radio/direction finder operators and ATC clerks had disappeared.  The new control room was deigned to accommodate three operational staff: The Aerodrome (or Tower) controller, the Approach Controller and the ATC Assistant. The controllers shared a desk facing south over the airfield with the assistant having one behind and at right angles.
 
Control Room Interior
 
The controller's desk is to the right, aerodrome lighting controls to the rear and assistant's desk on the left. Controller is Joe Kearney and ATC Assistants Walter Collister and Dougie Clucas.
 
 
Control Desk
 
The two controllers sat side by side, with the Approach Controller on the left and Tower Controller on the right. In quieter periods Approach and Tower were probably 'bandboxed' onto the Approach desk.
 
The Tower controller was responsible for all aircraft and vehicle movements on the airfield surface and for aircraft flying within the vicinity of the airport. The Approach Controller was responsible for clearing aircraft into the Control Zone and providing separation between Instrument Flight Rules (IFR) aircraft. Control was entirely by procedural methods, using vertical distance or time separation between aircraft. The only aid the Approach controller had to assist him in his task was a VHF CRT Direction Finder. The old ex Navy FV5 D/F was replaced in the early 1960s by a more modern Marconi AD210 unit. This was fitted with all the radio frequencies in use and could be switched from one to another at the push of a button. When an aircraft transmitted a message, the CRT display would emit a click and a bright blue line trace from the centre to the edge, where the bearing could be read off against a compass rose. Apart from the controller being able to pass bearings to aircraft and provide Direction Finder based approaches, the D/F was very valuable in building up a mental picture of the approximate position of aircraft under control.
 
 
Approach Controller's Desk
 
Weather reports clipped on the left, the main panel has a clock, controls and display for AD210 D/F, wind
dials with radio controls below. Flight progress strips on the sloping section of the desk in three reversible bays.
 
Marconi AD210 VHF CRT D/F
 
Control panel and frequency selectors at top, with the cathode ray tube display below. The D/F trace only displayed (with an audible 'click') while an aircraft was actually transmitting and vanished as soon as the transmission ceased.
 
 If several IFR aircraft arrived at the same time the first could make an approach with 'no delay' and subsequent aircraft would be held overhead the airfield, vertically separated using the Ronaldsway M/F Non Directional Beacon (NDB) for lateral guidance. Each aircraft would make its approach in turn and as levels in the hold were reported vacated the aircraft above would be descended. 'Expected Approach Times' (EATs) were issued to any delayed aircraft to enable pilots to ensure they had enough fuel in reserve. Outbound aircraft had to be integrated by keeping inbounds above them in the hold until lateral separation could be proved. All instructions and clearances were recorded on the Flight Progress Strips, which had been prepared in advance by the ATC assistant based on Flight Plans submitted locally or received by teleprinter.
 
An example of the problems facing a procedural approach controller can be found in the watch log from 3rd August 1963. Dan Air Bristol Wayfarer G-APLH had been cleared to depart IFR for Prestwick, climbing to maintain Flight Level 45. The routing specified was to Carnane NDB (south of Douglas) to climb overhead that beacon to FL45 before setting course to Blackhead (Mull of Galloway, Scotland). By the use of the D/F the controller discovered the aircraft was in fact heading towards Spanish Head to the west of the airport 'where a number of aircraft were holding' The captain was instructed to set course for Carnane and when later interviewed stated that his Automatic Direction Finder (ADF) had been 're-tuned from Carnane to Spanish Head' and apologized. Presumably he hadn't bothered to listen to the Morse identification transmitted by the beacons!
 
ATC Logbook 3rd August 1963
 
Entry detailing the navigation error in G-APLH that was only discovered by use of the D/F
 
The same aircraft and captain feature in the watch log the following day: G-APLH landed at 14:10 after an 'unorthodox' procedure onto runway 27. At 13:54 G-LH checked the IOM beacon with the coast in sight and was cleared for direct visual approach for runway 09. At 14:10 the pilot stated that he was downwind for runway 27 but did not have the airfield in sight. After being given QDMs (D/F bearings to the airfield) G-LH landed on runway 27. Another inbound aircraft, British United Airways G-YV (Dakota G-AMYV) had to be held at Carnane for twelve minutes until the Dan Air aircraft had eventually landed. Such were the delays and ATC problems with procedural approaches where you can't 'see' where the aircraft is. In the first example the D/F probably averted a serious incident if not accident.
 
 
Air Traffic Control Assistant Duties
 
The ATC assistant was now the sole 'support staff' for the controllers and had various duties assigned. Outside duties would include inspecting the airfield runways and taxiways before the station opened in the morning, as required during the watch and again before dark if night time flying was to take place. Most of the assistants duties were inside the tower however. Flight Plans and other ATC signals would be received by teleprinter, located on the ground floor of the tower. The Teleprinter Operator would tear the printed copy off the machine and dispatch it to the tower assistant via the Lamson Tube system. Similarly any outgoing signals, Flight Plans, Departure Messages etc. would be hand written by the assistant and sent 'downstairs' via the tube. The assistant hand wrote the Flight Progress Strips before passing over to the appropriate controller. After the flight had landed or for outbounds had been transferred to another agency, the assistant would record the details in the Aircraft Movement logbook and file the strip. Another Lamson tube routed to the Met Office and the Met Observer would hand write half hourly Met Observations on the appropriate form and dispatch to ATC upstairs.
 
Air Traffic Control Assistant Desk - 1963
 
Equipped with telephones, Movement log book and blank Flight Progress Strips. The Lamson Tubes are positioned right of the chair.
Pilots or company representatives would file Flight Plans with the assistant who, after checking them and correcting
any inaccuracies would add the Aeronautical Fixed Telecommunications Network (AFTN) teleprinter addresses for other relevant ATC units and dispatch them to 'teleprinters' via the Lamson Tube. The Teleprinter section shared a room on the ground floor with the airport switchboard.
 
AFTN Teleprinter Section
The Airport Telephone Switchboard
 
 
Ronaldsway Meteorological Office
 
The 'Met Office' was located on the first floor of the control tower and was staffed by a Met Forecaster and a Met Observer. The observer would make half hourly routine observations, recording them in a ledger and then sending a copy to ATC and another to Teleprinters, both by the Lamson Tube System. If conditions changed rapidly, 'special' observations would be made as required - if storms were passing by the observer could be very busy! The Met Forecaster prepared forecasts on a regular basis, disseminated as the observations to ATC via the 'tube' and the rest of the world by the AFTN teleprinter network. The forecaster also offered a personal briefing to ATC staff and to pilots who would all pop into 'Met' before taking up their duties.
 
 
 
Met Forecaster's Desk
Met Observer's Desk
 
 
 
1960s Navigation Aids
 
As mentioned before, the VHF D/F could be used to provide either a pilot interpreted 'D/F letdown' or a controller interpreted 'QGH' approach, the aim being to enable a pilot to descend through cloud until visual with the airport when he could make a 'circling' approach to land on the most suitable runway. With the 'GJE' Non Directional Beacon (NDB) at Ronaldsway approaches would have been published for the main 'instrument runway' of 27/09, aligning the aircraft more closely with the runway and having a lower permissible descent height do to the higher accuracy of the aid. The most accurate approach was using the Instrument Landing System installed on runway 27. Once the Glidepath element had come into use in June 1960 with the commissioning of the Santon Head Outer Marker beacon, instrument descents could be made to around 200 ft, with the pilot being assured that when he broke out of cloud the runway would appear directly ahead (wind drift permitting!).
 
 
Section of 1960 Airways Chart
 
From the start of the decade, showing NDBs 'MYI' at Cregneash and 'MVT' at Carnane. The Isle of Man Control Zone has changed from circular to rectangular with a small enlargement to include the NDB at Carnane.
(Click map for larger area)
 
With the adoption of the VHF Omni directional Range (VOR) as the UK primary en-route navigation aid a VOR at Cregneash, coding 'MYI', the same as the NDB, was 'on test' by July 1961with a frequency 113.9 MHz. The advantage of VOR over the previous Radio Ranges and Non Directional Beacons was that any course required could be selected, the Radio Range only offered four pre-determined courses.
 
By 1963 both the VOR and NDB at Cregneash had been re-coded to 'IOM' and there is a watch log entry for 7th June regarding a procedure that: 'Cambrian Airways are using for a VOR approach to runway 09' - they were reminded that this was unofficial! 
 
The 'IOM' VOR beacon at Cregneash
Working on the VOR electronics
VOR cabinets on right, NDB on the left?
 
VOR Course Deviation Indicator (CDI)
 
The basic aircraft instrument associated with the VOR. Pilot selected the required track to or from the VOR using the OBS knob, needle swings to left or right, when on the selected track the needle is centred. TO/FROM indicator to show direction of the VOR on course selected.
 
The VOR was supplemented in due course with UHF Distance Measuring Equipment (DME) giving the same VOR/DME capability that is still installed (albeit updated) there in 2012.  In the same period the Ronaldsway NDB was re-coded to 'RON'
 
Horizontal Situation Indicator
 
Later type of display for VOR/DME or ILS. The compass rose rotated automatically to show  aircraft heading, course (and heading for autopilot) selected with knobs, the bar indicated displacement from selected Radial/LLZ  with pointer to the left for ILS glidepath. DME distance displayed to top right of instrument.
 
 
Ronaldsway VHF Radio Frequencies
 
At the start of the decade Ronaldsway Approach was using 125.0 Mhz with Tower on 118.7 Mhz. The Tower frequency changed to 123.7 on the 29th February 1960 and on 16th January 1964 both frequencies were changed, Approach to 120.85 and Tower to 118.9. At 15:00 on the same day, the Station Telecommunications Officer, Mr Hewitson,  advised that Approach was reverting to 125.0 due to interference from Manchester Zone on 120.8. By the 11th February the problem had apparently been resolved and Approach went back to 120.85, both of these frequencies still being in use as of 2012.
 
The former Control Room on the second floor of the control tower was converted into a telecommunications equipment
room, with radios and tape recorders, with the old 'MCA Radio Room' towards the rear of the building also still in use.
 
The Duty 'Tels' Engineer's Desk
The former 'MCA Radio Room'
New equipment in the former Control Room
 
 
 Former RN Watch Office
 
The original RN 'Watch Office' unused for control purposes since the wartime years remained unoccupied in the early 1960s although from a 1963 photograph it looks like it might have been used as an office, possibly for flight planning by aircrews? The desk looks like the original control desk used in the 1940s & 50s. By 1966 the room had eventually found a use in ATC at Ronaldsway to house the new Approach Radar section which was to remain here until the move to the new control tower in 2010.
 
The old control desk in the 1940s RN Watch Office
 
 
 
Radar for Area Control
 
When first opened in the 1950s, Area Control at Preston Centre had been entirely procedural, using vertical and horizontal separations based on pilot reports. The first civil Area radar had been installed at London Heathrow in 1950 to assist the controllers at Uxbridge Centre and improve safety and expedite traffic around the various London Airports and by 1953 a joint civil/military radar unit was established at the Royal Navy Airfield at Stretton, in Cheshire. Known as 'Antrobus' this provided early radar coverage of the Manchester area but with the radars used having a maximum range of 60 miles, the  coverage didn't reach as far as the Isle of Man. 
 
Antrobus Type 15 Radar Aerial
 
Located at the RNAS Stretton 
(now mostly under the M56 motorway!) 
 
 
 
It wasn't until about 1963 that a Marconi S264A 50cm radar was installed at St Anne's, as part of a new civil ATC project to provide radar coverage of the UK airways system. By this time the Preston ATC Radar Unit (PATCRU) had moved to Manchester Airport, although the procedural controllers remained at Barton Hall, Preston. The new area radars were still 'Primary' only, so aircraft had to be identified by the radar controller either by a report over a notified 'Reporting Point' or by ascertaining the aircraft heading and instructing a turn of 30 degrees or more and observing the turn on radar. The controller then had to remember which 'blip' was which aircraft! There was a potential future development on the horizon though, the Air Traffic Control Radar Beacon System (ATCRBS), a development of the wartime Identification Friend of Foe (IFF), in 1961 it was on trial at London Heathrow airport for the Southern Air Traffic Control centre. Suitably equipped aircraft were allocated a 'Squawk' code which produced an enhanced 'blip' on the controllers radar screen. This was the forerunner of today's Secondary Surveillance Radar (SSR).
 
Radar at Manchester
 
Early radar displays as used at PATCRU, 
AD210 D/F installed between the control positions to assist controllers identify aircraft on radar.
(Picture via GATCO)
 
 
Marconi S264 Radar at the 1958 Farnborough Air Show
The St Anne's S264A Radar
 
The St Anne's radar would have given good coverage out to the Isle of Man and beyond, but although obviously of great assistance to the controllers at Preston, there probably wasn't much change in ATC procedures at Ronaldsway until radar was installed here. There was also a 10cm Type 80 Air Defence radar installed at Bishops Court in Northern Ireland in the late 1950s that was used for high level ATC by Ulster Radar, a Joint Air Traffic Control Radar Unit (JATCRU), It would have given excellent coverage over the Isle of Man, but was not available at Preston centre.
 
The huge Type 80 radar scanner (This one was at Sopley)
 
 
1966 - Radar installed at Ronaldsway (Again!)
 
By around 1965 the IOM Airports Board had decided to install radar at Ronaldsway. A popular airport radar at the time was the Plessey 424, a 3 cm radar, good for 'Surveillance Radar Approaches' but with severe limitations for vectoring and not approved for separating aircraft due to a very narrow vertical beamwidth. It was also prone to suffer from weather induced  'clutter'. Although considerably more expensive, it was decided to order a Plessey AR-1 10cm radar as installed at London Heathrow and Guernsey Airports. The radar scanner was installed on a mast above the control tower and the 1940s RN Watch Office converted into an Approach and Radar room.
 
Constructing the new Radar mast
The new Radar Scanner in position
 
The Approach controller moved down from the Visual Control room, leaving just the Tower controller and assistant there. 
Two radar displays were installed in a purpose made desk with, to the right, another desk housing the Approach controller and assistant,
 
Plessey AR-1 Radar displays on test - 1966
Wiring the Approach desk, Radar to the left
 
Inbound aircraft could be now sequenced with radar and separated laterally from outbound aircraft, cutting the inevitable delays when aircraft are controlled 'procedurally'. Surveillance Radar Approaches could also be provided, heading instructions being passed to keep the aircraft positioned on the extended runway centreline with advisory heights passed every mile, it being up to the pilot to adjust his descent rate to match.
 
There were no electronic 'video maps' to show airspace boundaries on the radar, perspex overlays being employed to show the final approach tracks and distances from touchdown. The radar display had to be manually aligned with these using radar reflectors positioned around the airfield. When the radar was out of service for any reason, control reverted to procedural. The Approach Controller sitting next to radar was still in charge and would speak to inbound aircraft on first contact, passing the latest weather and runway in use. Aircraft would initially be separated vertically or horizontally. The Approach controller would than hand control of the aircraft to radar, who usually operated on the same radio frequency. For Surveillance Radar Approaches a discrete VHF frequency could be used as the SRA required quite a lot of time critical transmissions and other aircraft calling could block the frequency.
 
 
AR-1 Radar Reflector
At the 'Barn Site'
 
Aircraft had to be radar identified by a position report from the pilot or by observing the reported heading for a period of time and giving a turn of 30 degrees or more and observing the turn onto the new track. The D/F was of major assistance here, given a radar display with maybe four or five 'possible' blips all heading in the same direction, a D/F bearing would usually indicate the most likely culprit! Departing aircraft could be identified by observing them appearing on the radar after the airborne time had been passed from Tower. If there was a conflict on the airway, inbound aircraft could be given a 'Radar Release' to Ronaldsway by Preston Radar identifying the aircraft in conflict to Ronaldsway by reference to a common place marked on both radar displays.
 
With the introduction of radar at Ronaldsway, a new radio frequency was also allocated, 118.2 MHz. The purpose of this was to allow a radar controller to carry out a Surveillance Radar Approach (SRA) on a discrete frequency. Providing an SRA can take up a lot of radio time and the controller's transmissions are time critical, so it was useful to have a quiet frequency for the purpose, so that a range check or critical heading correction isn't interrupted by a 'first call' on the approach frequency by a pilot who feels the need to pass his entire flight plan details on the first transmission. With two radar displays available, the second display could be used by another controller (if one was available!) to split the radar functions, Radar One carrying out initial vectoring using shared frequency 120.85 with Approach, Radar Two providing SRAs on 118.2.
 
 
Surveillance Radar Approaches
 
The AR1 radar was approved for providing Surveillance Radar Approaches (SRAs) to 2 miles from the runway. Before the approach began the controller would read out 'the spiel' - 'This will be a surveillance radar approach terminating at 2 miles from touchdown. Obstacle Clearance Limit is 650 ft, check your Minima'.  The controller would then vector the aircraft to a closing heading for the Final Approach Track and descend it to the minimum initial altitude as shown on the Radar Vectoring Area chart, at Ronaldsway usually 1,600 ft. At 8 miles from touchdown the radar controller would press the 'request' button on the Landing Clearance Indicator System (LCIS). This activated a buzzer and light in Tower where the controller had a choice of three reply buttons 'Land', 'Continue' or 'Overshoot'. Routinely the 'Continue' button would be pressed at this stage and the appropriate light illuminate in radar.  The pilot would be requested to report when he had the runway or lights in sight as the SRA could normally be discontinued at this point. As the aircraft approached the runway extended centreline small heading changes would be given by radar, usually of 5 or 10 degrees, to keep the aircraft tracking the final approach track and the pilot requested to 'Check Wheels'. At 5.5 miles from touchdown the pilot would be instructed to commence descent to maintain a 3 degree glideslope. Every mile from touchdown an advisory height would be passed and the pilot would adjust his descent rate appropriately. Radar continued with heading changes as needed and at 4 miles from touchdown would press 'Request' on the LCIS again, hopefully obtaining a 'Land' light from the Tower controller, whereupon the pilot would be cleared to land. At three miles from touchdown the advisory height would be passed together with 'Check Decision Height'. At two miles any final heading correction needed would be passed together with the advisory height and 'Approach completed'. If the pilot did not have the runway in sight an overshoot would be commenced with climb to a height as instructed by the controller.
 
Initial phraseology for SRA - click for more
 
 
Special Rules Zone Zone
 
In the late 1960s the Isle of Man controlled airspace was upgraded to include a Special Rules Zone. Initially the SRZ was a smaller dimension that the Control Zone, having a dimension of 5nm around the airport and up to 2000ft. Previously a pilot flying under Visual Flight Rules could enter the control zone without permission from ATC, but the addition of the SRZ meant that any pilot had to contact Ronaldsway by radio, preferably at least 10 minutes before ETA at the SRZ boundary and obtain permission to enter the zone. Whilst within the zone he had to maintain two way radio contact with ATC and obey any instructions issued. Aircraft not fitted with radio could still enter the zone but had to telephone ATC in advance and comply with any restrictions imposed. Eventually the SRZ was expanded to have the same dimensions as the Control Zone, giving ATC total control over their airspace.
 
Isle of Man Control Zone & Ronaldsway Special Rules Zone - 1968
 
 
ATC in the 1970s
 
Unless otherwise credited, all pictures on this website are  © Jon Wornham