Thursday 18 October 2012
Guernsey Airport is installing a temporary support frame at the western end of the airfield to relocate one of the key navigation systems.
The orange antennae that were previously clearly visible on the higher ground above the former La Mare Road were dismantled this week to allow work to start on the new section of runway at the western end.
These antennae, known collectively as a 'localiser', are part of the instrument landing system (ILS), which is a critical navigational aid for airport operations. It provides precise guidance information to approaching aircraft, enabling pilots to locate and align with the runway in periods of low visibility.
The Airport 2040 project includes the replacement of the current ILS localiser, and its relocation to correspond with the new western end of the runway when all the work is complete.
Neighbours to the west had expressed concerns regarding the resulting visual impact of the new localiser, which has to be in an elevated position. At the planning application stage it was envisaged this would be more than 10 metres high, and involve a concrete support structure.
However following detailed specification by the airport's ILS suppliers, the height and profile of the structure has been considerably reduced. The final installation will be only be 5.3 metres tall, and comprise a series of 12 green poles with antennae mounted on top, at the westernmost point of the airport boundary.
The final support frame will not be delivered for several weeks, but the localiser has to be switched off so construction can begin on the new section of runway. As an interim measure, the airport is installing a temporary steel support frame to mount the existing antennae.
Airport Director Colin Le Ray said the reduction in height, following very detailed technical work, was very welcome. It was also important to minimise the time the ILS was out of action, so as not to adversely impact on flights over an extended period.
"For the efficient operation of the airport, it is imperative that the system is reactivated as soon as possible, and hence the need for the temporary structure. We can only apologise if this is less sightly than the final design, but we would stress it is only a short term measure.
"'The project team was very conscious of the concerns some neighbours in the west had regarding the final design of the ILS localiser. We are very pleased this has been reduced considerably following the detailed technical specification work, which could only be done once the supplier had been appointed.
"Over the last 18 months our supplier, NATS, has developed modelling that enables the height of equipment to be reduced. This takes advantage of more accurate signal reflection off the ground in front of the equipment, and has been trialled successfully at a number of UK airports. We are now benefitting from that innovation."
The airport is writing to neighbours at the western end to let them know about the design change and the temporary installation.