Modernization of instrument landing systems ILS/DME 22 „IBG” and ILS/DME 09 „IWN“ CAT I at Burgas and Varna atc Centres
The Instrument Landing Systems (ILS) at Burgas and Varna ATC Centres are designed to provide the aircraft crew, approaching to land on runway 09 at Varna airport and runway 22 at Burgas airport according to CAT I terms of ICAO, with the necessary navigation information regarding course, angle of descend and distance to the runway threshold.
In the period 2017-2018 was realized a project for modernization of the two instrument systems at the international sea airports Varna and Burgas. The scope of the modernization project includes: supply and replacement of the LOC radio frequency equipment, supply and replacement of the Glide Path (GP) radio frequency equipment due to expiring exploitation cycle of the old equipment, as well as supply of new low-power Distance Measuring Equipment (DME), as an ILS subsystem. The supply of DME replaces the markers used so far (MM, OM).
After the modernization, the instrument landing systems ILS/DME 09 „IWN“ and ILS/DME 22 “IBG” CAT I at Varna and Burgas ATC Centres consist of localizer transmitter LOC 421, glide path transmitter GP 422 and Distance Measuring Equipment DME 415RPM, manufactured and integrated by Thales Italia S.p.A.
The localizer transmitter model 421 provides information about the course of the aircraft approaching to land on the runway, relative to the runway axis. The glide path transmitter model 422 provides information about the position of the aircraft relative to the inclined plane with a nominal glide path angle of descent to the runway touch-down point. The nominal value of the angle of descent is 3 degrees. The Distance Measuring Equipment DME 415RPM provides information about the distance from the aircraft to a ground reference point. For the DME, part of ILS system, the reference point is the runway touch-down point or the runway threshold – the latter case is presented in the graph below:
After the modernization, the two instrument landing systems ILS/DME 22 „IBG” and ILS/DME 09 „IWN“ Cat I at Varna and Burgas ATC Centres were put into operation in the first half of 2018.