The CATIIIB classification means the runway may be utilised when visibility falls below 125 meters, making it a fully independent runway system.

Accommodating maintenance needs

An outstanding benefit of the runway has been to allow maintenance of others runway whenever necessary, without affecting scheduled landings and takeoffs – essential with AUH operating 24 hours per day, seven days a week.

More on ILS classifications

Most commercial and scheduled flights run under a system of regulations called Instrument Flight Rules (IFR). This system allows pilots to fly using aircraft instruments only, even in situations where visibility is impaired, such as flying into clouds or landing in dense fog.

To assist pilots landing under IFR, airports incorporate Air Traffic Control Tower (ATCT) systems and lighting systems on their runways – known as Instrument Landing Systems (ILS).

The accuracy of the ILS at a particular runway gives it a classification from CAT I (the least accurate) to CAT IIIC (the most accurate). The category of a runway determines how low an aircraft can fly before being required to see the runway.  For example, a pilot landing at a runway designated as CAT I must be able to see the runway from a height of at least 200 feet (61 metres), whereas a pilot landing at a CAT II runway can get to an altitude of 100 feet (30 metres) before they see the runway. The height at which the pilot must be able to see the runway is referred to as the “decision height”.

Crucially, the North Runway is fitted with a full CAT IIIB Instrument Landing System, which allows for an approach under IFR with a decision height lower than 50 feet (15 metres) and a runway visual range (the distance a pilot can see down the runway) of only 150 feet (46 metres).