The 1990s - Major
Changes to ATC at Ronaldsway
The 1990s were a period
when a lot of new equipment was introduced, including radar and communications
equipment. Control techniques remained much the same as had been established
with the arrival of radar. In Approach there was generally both an 'Approach
Procedural' and 'Approach Radar' controller, with an Air Traffic Control
Assistant to prepare flight progress strips and handle telephone calls,
most often involving receiving inbound estimates on aircraft from the centre
and passing airborne times on departures. All arrivals and departures were
individually co-ordinated with Manchester Centre by the Approach Procedural
controller, who would then pass the flight progress strip to the Approach
Radar controller if vectoring or radar separation was required. An '8 mile
check' would be passed by intercom to the Tower controller upstairs as
the only surveillance equipment Tower had were eyes, binoculars and the
radio direction finder. The D/F had been upgraded to a large display unit
which gave a digital readout of aircraft transmission bearings. In the
early 1990s the large displays were replaced by more compact units, still
in use in 2010. Inbound instrument traffic would be integrated with visual
circuit traffic based on the '8 mile check' and much searching through
the tower windows! The Direction finder was also a great help in showing
which direction to look out of the windows for your circuit traffic.
    
Surveillance Radar
Approaches & the LCIS
When I first started
work at Ronaldsway in 1990, the standard instrument approach offered for
runway 09 was a Surveillance radar Approach (SRA) terminating at 2 miles
from touchdown, or earlier if the aircraft became 'visual'. A useful piece
of equipment installed was the Landing Clearance Indicator System, or LCIS,
a simple system comprising light indicators and a buzzer between radar
and tower controllers.. When the aircraft was at 8 miles from touchdown
the approach controller would press the 'request' button, triggering a
a buzzer and light in Tower. The tower controller had three reply buttons,
'Clear, Continue or Overshoot' and would generally press 'Continue' at
this stage. At 4 miles from touchdown, Radar would press 'Request' again
and hopefully receive 'Clear' in response, enabling him to clear the aircraft
to land. Another 'Continue' would generally result in some enquiries via
the intercom, as instructions said that if landing clearance was not received
by 2 miles from touchdown the aircraft had to be overshot, resulting in
more vectors and another SRA!
     
  
Denro Comms
In the early 1990 the
old locally built communications equipment was replaced by a new system
from American company Denro. Although this was a major advance on the previous
system, it had some serious faults which were never satisfactorily resolved
and in due course it was replaced.
1995 - Watchman Radar,
colour radar displays and new Tower Desk
In 1995 the time expired
AR15 radar was replaced by a Plessey Watchman with new colour computer
displays and an
Aerodrome Traffic Monitor
(ATM) radar repeater screen in the Visual Control Room. To accommodate
the extra equipment, the 1960s wooden desk was removed and replaced by
a longer metal construction with the controller on the left had side and
assistant on the right. The radar was still primary only, all aircraft
had to be identified on first contact, usually by requesting a VOR radial
and DME distance from the 'IOM' and correlating it with the blip on the
radar screen, or by giving the aircraft a turn of at least 30 degrees and
observing the change of track. More unusually, the area controllers at
Manchester would give a 'radar handover' and identify the aircraft to approach
radar using reference to a common point on both radar displays. Eight mile
checks were still passed from Radar so that Tower would know the identities
of the blips on the ATM.
    
 
1998 - Secondary
Surveillance Radar
In 1998 a Cossor Secondary
Surveillance Radar (SSR) system was added, introducing a second radar aerial
on top of the Watchman one and providing aircraft labels and height information
on the radar displays. This introduced aircraft identification labels on
the radar screen, together with a readout of the level of each aircraft.
Introduction of SSR was a major advance and eventually paved the way for
a major reduction in the amount of co-ordination between Radar and Tower
and Radar and Area Control, considerably cutting the number of telephone
calls needed. Staffing in the Radar room now tended to be just a radar
controller and assistant, although the assistant had other duties and was
not always present.
   
Frequentis Comms
Towards the end of the
1990s, the Denro communications system, which had proved unsatisfactory
at Ronaldsway, was replaced by a new Frequentis system, using touch screen
technology, which is still in use.
   
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