around the Isle of Man 1970
Airway Red 3 routed
overhead the 'IOM' VOR/DME from Wallesey to Belfast, both also defined
with VORs although Belfast at this stage hasn't been equipped with DME.
The VORs are backed up by medium frequency NDBs, the 'IOM' beacon radiating
on 391 Khz. Although the old Radio Ranges have been replaced by the VORs,
the associated 75 Mhz marker beacons are still there, with the Portaferry
and Point Lynas markers shown. Airway Red 3 has a surprisingly low base
level of Flight Level 40. Also shown are Advisory Routes 'Delta Whiskey
2', from the Pole Hill VOR to Carnane NDB ('CAR' on 366.5 KHz) and 'Delta
Green 27' from Blackpool to Carnane. To the south west, another advisory
route 'Delta Whiskey 11' has two options, both start at the 'IOM', one
routes to the Dublin VOR and one to the Rush NDB. Controlling authority
for the airways and advisory routes is Preston Centre using 125.1 MHz with
Radar available. Flight Information Service also available outside controlled
airspace with Preston on 126.85 MHz.
The Isle of Man Control
Zone has been expanded from the original circle to an oval shape, no doubt
to accommodate the instrument approaches to runway 27/09, the zone goes
from surface to Flight Level 55. Ronaldsway has an NDB 'RON' on 322 KHz
and 'Homer' (VHF D/F) on 120.85 MHz. There is another NDB on the airfield
at Jurby 'JY' on 358 Khz
1970s Airway Chart
to the south and east of the Isle of Man,
To the north, advisory
route 'Delta Green 27' has made a kink from Carnane to the 'IOM'
and then continues to the Killantringan reporting point on the Mull of
Galloway before continuing to the Prestwick VOR. Similarly 'Delta Whisky
11' has kinked from the 'IOM' to Carnane before heading north east to the
Dean Cross NDB in Cumbria and onwards to Newcastle.
1970s Airway Chart
to the north
of the Isle of Man
Preston Air Traffic
Procedural Airways Control
- Flight Progress Strips, clocks, radio & telephones! By this
time Preston did have radar, but the controllers were at the Preston Air
Traffic Control Radar Unit (PATCRU) which was in fact at Manchester Airport.
Procedural and Radar controllers worked on the same frequency with an intercom
available between the positions.
(Picture via GATCO)
When using procedural
control, i.e. without radar, the two radio beacons and the kink in the
advisory routes made operating easier as the 'IOM' and 'CAR' beacons were
'deemed separated' e.g. an inbound aircraft from Blackpool could be cleared
to the 'CAR' at 3000 ft at the same time as one from Dublin was cleared
to the 'IOM' also at 3000 ft. For Ronaldsway, if the radar was out of service,
the holds at 'IOM' and 'CAR' would be very useful for climbing or descending
an aircraft though the level occupied by another, knowing that while in
the hold they were separated from each other. Right up until the 1990s
the usual mode of operations for Ronaldsway was that the procedural 'Approach'
would solve as many separation problems as possible before handing control
to Radar. All aircraft had to be cleared to a beacon procedurally separated
from all others until the radar controller had identified the relevant
'blips' on his screen and could then use radar separation between aircraft
at the same level.
Concorde Flight Testing
There are regular notes
in the Ronaldsway watch log from about August 1970 regarding supersonic
test flights by the Concorde prototype 002, G-BSST, based at Fairford
in Oxfordshire. A test route had been established from Fairford, eastwards
to The Wash, then accelerating to supersonic speed along the east coast
of England, up around the north of Scotland and back along the west of
Scotland and Wales, which must have been close to the Isle of Man. A monitoring
station was installed at Ronaldsway in the D/F hut and presumably the equipment
needed to be turned on when a run was about to happen. After a run had
been recorded, a Devon aircraft from the Royal Aeronautical Establishment
would fly into Ronaldsway to collect the data recorded.
(Thanks to Chris Cook
for the information on this) On the 12th November 1970 captained by Brian
Trubshaw Concorde 002 achieved Mach 2.0 for the first time. Unfortunately,
apart from notification of the flight taking place, there is no other comment
in the log.
Preston Air Traffic
Control Radar Unit
A radar control console
at PATCRU located at
(Picture via GATCO)
Concorde Flight Plan
As received on the teleprinter
at West Drayton. This was by one of the later flight test aircraft, G-AXDN
No 01, for a supersonic flight out over the Atlantic Ocean and back
to Fairford. This aircraft is preserved at Duxford.
Changes on the Airfield
At Ronaldsway, the aircraft
parking aprons had continued to expand to cope with the larger aircraft
now coming into service. From the 1960s Vickers Viscount turboprops were
common, first with BEA and then Cambrian Airways when they took over the
Isle of Man routes in 1963. Viscount G-ALWF pictured below was operated
by Cambrian from 1966 to 1971 and would have often been operating on Isle
of Man routes. It is now preserved at Duxford.
Concorde 002 G-BSST
Preserved at the Fleet
Museum, Yeovilton Somerset
Initially the control
tower remained in splendid isolation on the airfield and aircraft could
taxi and park between the tower and the terminal building, but it was decided
to build a pier connecting the two together and so in 1971 they were linked
by a 'temporary' wooden pier, used for the new phenomena of security screening
departing passengers who then waited in a holding lounge (Gate 8) until
boarding their aircraft. If it was parked on the west apron, progress to
or from the control tower was hindered as the corridor would be closed
off to allow the departing passengers to cross over.
Preserved BEA Viscount
The control tower accommodation
was also improved in the 1970s with an extension built onto the west side
of the radar room to provide an office for the Senior Controller (SATCO)
and a combined rest and locker room for the staff.
pier in 1971
Aerial view of the
completed pier in 1975
The Control Tower
With the first of two
built onto the side
Area Control Changes
During the 1970s Secondary
Radar (SSR) came into widespread use in area control. Initially only having
64 discrete codes it was expanded to today's limit of 4096 codes. Modern
radar displays were able to show the allocated code next to the primary
radar 'blip' and aircraft could be identified using the allocated 'squawk'
code as set on the aircraft transponder. This was 'Mode A' and a further
development, 'Mode C' linked an altimeter in the aircraft to the
transponder and the controller was able to see the actual level of the
aircraft on his display. Using early computer technology it was possible
to produce a 'Code/Callsign Pair' and associate a squawk code with the
aircraft callsign, e.g. transponder code 3011 might be allocated to flight
BE4902. In the early systems the controller would observe the code on his
display, 3011 and ask the aircraft to 'squawk ident'. The pilot pushed
the 'ident' button on the transponder which activated the 'SPI' function,
causing the aircraft position symbol on the radar display to flash for
several seconds. It also triggered the Code/Callsign function in the radar
processor and code 3011 would be replaced with the aircraft callsign 'BE4902'.
The Visual Control
Room in 1971
Associated with Ronaldsway
since the 1930s, controller and former pilot Jimmy Hesketh is pictured
with ATC Assistant John Chadwick at the desk behind,
1971 The new London
Air Traffic Control Centre
There had been plans
to move the Southern Air Traffic Control Centre from its location to new
accomodation in the mid 1960s, but as often seems to happen, there was
a delay and it was not until 1971 that the new London Air Traffic Control
Centre became fully operational at West Drayton, a few miles north of Heathrow.
Initially just the Procedural Controllers moved across into what was know
as the 'Stage 1/2' operations room whilst the more permanent 'Stage 1'
operations room was being prepared. The radar controllers moved across
from the SATCC on the night of the 31st January 1971 when the new ops room
was ready. ATC en-route radars were 'piped in' via broadband radio
links from sites at Heathrow, Ash (Kent) and Ventnor (Isle of Wight) and
displayed on flat top 'scan converted' (basically a TV picture of the radar
picture) diplays, backed up by vertical displays on the back of the sectors.
Initially, SSR returns were not available and controllers kept track of
aircraft identities by moving 'Shrimp Boats', small perspex markers, across
the display to keep up with the radar blips. New remote radar sites
at Burrington (Devon) and Clee Hill (Shropshire) were being constructed,
from these the radar data was to be digitised at the site and transmitted
to West Drayton via land lines. Until the Burrington site came onto
line the Southern Radar joint civil/miltary radar at Sopley (Hampshire)
continued in operation using a Type 80 radar and from an underground bunker.
St Anne's Radar with
A processed Radar picture
from the St Annes
S264A and SSR
Also located in the
same building was the London Military control centre, which was in the
room next door to civil operations. In another building on the site
was the UK Air Defence Data Centre, which was designed to coordinate all
of the air defence radars into a single control site, making extensive
use of computers to process the data from both civil and military radars
around the UK. Unfortunately, the computers of the day proved insufficient
to carry out the task and as far as I can tell the ADCC never became operational.
The London Air Traffic
LATCC Civil Operations
1975 - Preston
Centre Closes - Manchester Sub-Centre Opens
Preston Centre closed
in 1975 with most of its functions transferred to the London Air Traffic
Control Centre at West Drayton. However a sub-centre was established in
the control tower at Manchester Airport, which remained responsible for
the airways around the Isle of Man at lower levels. Co-ordination would
have remained much the same with clearances being requested by Ronaldsway
for outbound airways aircraft and releases passed by Manchester on inbound
flights. Every departure clearance and inbound 'release' was individually
negotiated and levels agreed based on traffic to keep procedural separation.
The 'release' on inbound aircraft was a Position, Time or Level at which
the Centre handed control to Approach, for instance 'Released passing flight
level 90'. Communications might be transferred to Approach earlier, but
until the aircraft had passed FL90 in the descent, Ronaldsway Approach
or Radar could not issue any control instructions, for example radar turning
the aircraft for identification.
LATCC En-Route Sector
The sectors at Manchester
were West Drayton type 'Mediator' consoles, which combined the procedural
and radar functions. The controller sat in front of a horizontal radar
display, with the Flight Progress Strip board above and sometimes another
vertical radar display behind to show the picture from an alternative radar
source. In general there were two (expandable to four) controller positions
on a 'suite' with a 'Senior Sector Controller' known as the 'Crew Chief'
central and Assistant's positions outboard on 'the wings'. The Crew Chief's
function was to oversee the operation of the sector and carry out co-ordinations
with other sectors and airfield, e.g. Releases to Approach. Information
written on the strips was 'colour coded' so that it was immediately apparent
as to who had written what. Assistants wrote in black pen, Controllers
in red and Crew Chiefs in green.
A map from November
1974 showing the new
area of responsibility
to be assumed by the sub-centre
If a confliction at
the point of release from Centre to Approach could not be resolved procedurally
it was possible to use a 'Radar Release'. This involved the radar controllers
co-ordinating directly, the Manchester Centre controller would ring Ronaldsway
and ask to speak to the radar controller. Starting with the words 'Radar
Release' he would identify the conflicting aircraft to Ronaldsway using
points marked on both displays, e.g. 'Cambrian 602 is bearing 130 degrees
from the IOM at 33 miles'. Once both aircraft were identified to Ronaldsway
and the terms of the release agreed the aircraft would be transferred.
New Scottish Air
traffic Control Centre
In 1978 Scottish control
moved from the old building of Redbrae on Prestwick Airport to a new location
in Prestwick town named Atlantic House. The building had been constructed
as the area headquarters for the National Coal Board but was refurbished
as an Air Traffic Control Centre. There were three elements to the
unit, Scottish Airways, Scottish Military and Scottish Oceanic.
The latter controlled aircraft over the North Atlantic until the 'half
way point' at 30 degrees west, where Gander Oceanic in Canada took over.
The new building allowed the radar controllers for Scottish Airways to
move into the same operations room as the procedural controllers and the
radar unit at Gailes (near Irvine) was closed down. The operations
room design differed from West Drayton and Manchester with their orange
horizontal radar displays, with semi vertical green displays being provided.
Area Control 'Mediator'
This is actually the
Pole Hill sector at
West Dayton, one of
the former Preston sectors transferred in 1975. The Manchester sub-centre
was similarly equipped.
in the 1980s
Atlantic House, Prestwick