Spectacular Sydney landings

SYDNEY Airport in Australia operates two parallel runways set at 1,037 metres apart.

Using a procedure called independent visual approaches (IVA), two aircraft can be on final approach at the same time while operating in visual meteorological conditions.

IVAs are safe and efficient to perform – providing a spectacular rare sight of planes in side-by-side formation preparing for landing.

The airport’s two parallel north-south orientated runways (16L/34R and 16R/34L) handle the majority of movements annually. Designed to provide safe and practical parallel runway operations when weather conditions prevent independent visual approaches, the Precision Runway Monitor (PRM) technology used is a highly accurate surveillance system that allows pilots to accept reductions in lateral separation standards during an instrument landing system (ILS) approach.

At the heart of the system is a high resolution radar providing a very fast update rate for display to a specialist PRM controller monitoring each approach. A ‘No Transgression Zone’ (NTZ) with a width of 610 metres/2,000 feet is established between the parallel approach paths to provide a suitable safety buffer between aircraft on adjacent ILS approaches.

Using PRM, aircraft can be processed independently of any traffic on the adjacent approach track, whereas air traffic control would otherwise apply a two nautical mile staggered separation between aircraft on parallel ILS approaches.

The PRM is vital in maintaining airport capacity and reduces air traffic delays by as much as 80 per cent in poor weather.