compassion, collaboration & cooperation iN transistion
Project Linesman was one of the main reasons why West Drayton became
the site of the UK Air Traffic Control Centre. Linesman was designed to be
the hub of the Air Defence Environment. The Initial Concept was formulated
in the 1950s at the height of the Cold war and was for threat assessment and
communication that could launch retaliation against a nuclear attack from
Linesman would collate data from the East Coast of England and
Continental radars via telephone lines and pass on the information to
Air Defence Chiefs at West Drayton and strategic bomber stations.
The Vulnerability of L1 to air attack was recognised and second
underground site L2 was planned, but never built. As the system
requirement evolved, along with computing methodology, so costs and
timescales escalated. In an attempt to control these, the then Labour
Government took the decision in 1962 to combine the civil and military
control sites and a prototype system was installed in building 123 in 1963.
It was at this time that The Eurocontrol Convention was convened, signed
and subsequently ratified as that which became the European Organisation
for the Safety of Air Navigation. Buildings including 123 were completed
in 1965 and in 1969 contracts were awarded to Plessey for military radar
data processing and to Marconi for a display system and civil flight data
processing. RAF controllers and their equipment were to be housed in L1
with the civil complex in the adjoining LATCC. Thankfully Linesman was
never used in anger, but it did provide a service for exercises and training
fighter controllers, and was utilised for the purpose of my own training as
The first Civil Flight Data Processing system installed in LATCC in 1967
was based on a Ferranti HERMES computer. The software contained
representations of the airway and link structure, reporting points, wind
data and Heathrow runway in use - all on a storage capacity of only 8k of
24 bit words, later upgraded to 32k. Operational support was provided by
offline bureau and program development test computers. This system,
referred to as MEDIATOR, provide procedural flight control for the first
LATCC ATCOs as Stage 1/2 of the FDP project that would eventually lead
to all civil ATC for England and Wales [BE]ing located at West Drayton.
All MEDIATOR input was made by ATSAs at teletypewriters in the Data
Extraction cell, who got their information from teleprinter tapes or
telephones. Output from MEDIATOR was in the form of flight strips that were
printed at a central location, machine-loaded into holders and distributed to
sector controllers by ATSAs. The HERMES computers remained in service until
1976 when they were eventually replaced by the 9020D complex.
Southern Radar from Sopley moved to West Drayton in 1974, followed by
Western Radar from Aberporth. By now both civilian and military air traffic
levels were increasing and, in order to improve safe and efficient use of the
South East air space , SEJAO was inaugurated with military and civil ATCOs
working side by side in the newly commissioned CASOR. Fairly rapidly over
the next few years the number of SEJAO sectors expanded from four to eight
and the title changed to LIAO. When the Linesman system became operational
the first people to use it were the School of Fighter Control, who moved from
RAF Bawdsey in 1974. Then in 1975, the ADGE Examining Board 9 ...
"the dreaded Trappers" moved in from Bentley Priory. Both these lodgers
stayed until 1990.
During the operational lifetime of LATCC, that is from taking control of the
UK Civil Air Traffic from SCATCC until TC took executive control at Swanick,
it handled a total of 48,206,332 movements, ALL of THIS with NO ATC
attributable ACCIDENT! • a very remarkable achievement that is a fitting
tribute to all who had worked at West Drayton over the years.
As [IS] in[DEED] often the case, one era closes and yet another unfolds, which
in the case of Global Air Traffic Control, is NOW been assisted by the advent
of that which is referred to as GNSS.
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