Go-Around Detection System (GARDS) warns air traffic controllers of go-arounds

Air Traffic Control the Netherlands (LVNL) has built a signal into the air traffic control system for improved safety when an aircraft makes a go-around. This system, which is unique in the world, gives an audio prompt and shows a warning signal on the radar monitor, reducing the risk of an unsafe situation. LVNL continually improves the safety of take-offs, landings and handling of air traffic in Dutch air space.

Go-arounds occur regularly (about 350 times per year with 230,000 landings) and follow a standard procedure. With a go-around, the landing of the aircraft is aborted. There may be various reasons for this, such as exceptional weather or technical conditions, or because the previous aircraft is still on the landing runway. It is also possible that the cabin crew of the aircraft have yet not been able to make all the preparations for landing. Depending on the situation, a go-around may be initiated by the pilot or the air traffic controller.

The air traffic controller issues instructions to aircraft that are landing and taking off from the control tower at Schiphol. In order to provide extra alerts for air traffic controllers in the case of a go-around, an automatic system has been developed, which gives both an audio prompt and makes a warning signal visible on the radar monitor. In the past, situations have occurred in which an air traffic controller has seen an aircraft touch down, yet ultimately, a go-around has nevertheless been made. This has led to high-risk situations.

Schiphol runway system
Schiphol has take-off and landing runways that are used with different wind directions. Some of the runway combinations can lead to air traffic that could intersect in the air. Because go-arounds are never planned, the potential intersection of air traffic arises unexpectedly. It is therefore important to have a clear overview of the situation.

Robert van Diemen, Director Operations at LVNL says: ‘The Go-Around Detection System gives the air traffic controller a signal that an aircraft is making a go-around. This ensures that the air traffic controller is aware of the go-around and can take action if necessary.’

LVNL developed GARDS itself. The system has been extensively tested and evaluated. The air traffic controllers who work in the control tower have received training in the use of the system.

The preliminary research was performed partly by NLR and was made financially possible by the Knowledge & Development Centre Mainport Schiphol.

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