It’s been almost two years since an eight-aircraft loss of separation incident occurred at Madrid Airport. However, the final report was finally released on 6 February 2020 by Spain’s civil aviation investigation body – the CIAIAC (Comisión de Investigación de Accidentes e Incidentes de Aviación Civil). Here’s what happened and why.
How did it start?
According to The Aviation Herald, on 27 May 2018, Madrid Airport had been operating in a North Configuration (landings on runways 32L and 32R, departures on runways 36L and 36R).
However, between 20:47 and 20:54 local time, seven arriving aircraft went around due to changing weather conditions which included wind shear (loss of speed). Responding to these changing conditions, the airport decided to change to the South configuration at 20:54. The meant that landings would take place on runways 18L and 18R, and departures on runways 14L and 14R. The result of this was a complex traffic scenario leading to a number of losses of separations involving eight aircraft.
SKYbrary defines loss of separation as whenever the specified minimum separation distance between aircraft is breached. Minimum separation standards for airspace are specified by ATS authorities, based on ICAO standards and include both horizontal and vertical space. Needless to say, loss of separation can be very dangerous as it leads to potential collisions between aircraft.
Below is a list of the losses of separation and the details in the aftermath of the go-arounds and switch of airport configuration:
- Firstly, a loss of separation occurred around 21:36. The separation between two aircraft reduced 61m vertical and 1.48km horizontal. This involved a TAP Air Portugal Airbus A320-200 on final approach to runway 18R and an Air Nostrum Canadair CRJ-1000 (on behalf of Iberia) on final approach to runway 18L.
- The second loss of separation occurred around 21:52. This time, the separation between two aircraft reduced to 99m vertical and 2.22km horizontal. This involved another Air Nostrum Canadair CRJ-1000 on behalf of Iberia, on final approach to runway 18L as well as a Ryanair Boeing 737-800 on final approach to runway 18R.
- The third loss of separation occurred around 21:58. The separation between the aircraft reduced to 0 meters vertical and 1.67km horizontal. This involved an Iberia Airbus A320-200 on final approach to runway 18R and a Ryanair Boeing 737-800 on final approach to runway 18L.
- Finally, the fourth loss of separation occurred at 22:03. Here, the separation between the two aircraft reduced to 122 meters vertical and 1.85km horizontal. An Air Europa Boeing 737-800 was on final approach to runway 18R while an Air Europa Airbus A330-200 was on final approach to runway 18L.
How did it happen?
According to the Spanish-only report, the conclusion is that the losses of separation were the result of a ‘complex operational situation’ in the Madrid control zone. There are a number of factors that led to this including:
- The unavailability of weather information tools covering the entire Madrid control zone
- A sudden change in weather conditions, particularly in intensity and wind direction
- And the time needed to make the decision to switch runway configuration.
The CIAIAC report states that Madrid ATC consulted with the weather forecaster who explained these were convective currents with variable directions which would last for about one hour. At 20:54 local time, the decision was made to switch the runway configuration.
Switch of configuration was a large factor in the incident, which occurred in a critical situation. The report states that the switch takes about 10 minutes before normal operations are re-established. In the midst of this, sector assignment and some technical problems further complicated the switch.
The report recommends improving the coordination of ATC services and weather forecasters as well as the weather observers at the aerodrome. In the end, six safety recommendations were issued by the CIAIAC to the ATC provider. Furthermore, two recommendations were made to the weather service provider.
We chose to summarize the report in the interest of our broad readership, which ranges from former and active pilots to business travelers. Most may be lost in the numerous technical details and figures presented.
If you’re a pilot or work in the field of ATC, let us know your thoughts on what happened above by leaving a comment!