08.01.2003
Why snow chaos at Copenhagen Airport?

Were the airport’s snow contingency plans insufficient?

The snowfall last Sunday was expected, and the airport’s snow contingency plans worked as intended in all respects.

Even under "normal" winter weather conditions snow will inevitably cause delays. Runways and taxiways must be closed completely while they are cleared of snow. This means that aircraft ready for take-off must stay on the ground, and aircraft in approach must stay in the air and wait for landing clearance while the snow is being cleared. In some cases, airlines choose to redirect their aircraft to other airports.

Another factor causing delays is de-icing. All aircraft must undergo a time-consuming de-icing procedure to remove ice and snow from the wings and hull of the aircraft before take-off. De-icing is carried out by the airlines or their respective handling companies subject to agreements made without the airport’s involvement. The airport has four de-icing stations. Last Sunday and Monday, the handling companies had chosen to staff only three de-icing stations.

Both snow clearing and de-icing causes minor delays in normal circumstances. Sunday, 5 January 2003, was characterised by a heavy snowfall and extreme winds, which resulted in further problems and major delays.

Why did we not use the runways and taxiways available?

Normally, all take-offs and landings are carried out from the airport’s parallel runways, the 22R/04L and the 22L/O4R. Only in case of high south easterly or north easterly winds (0.8 per cent of all take-offs and 4.2 per cent of all landings) is the cross runway, the 12-30, used. The limited use of the cross runway is due to the fact that in most cases take-off and landing involves passing over residential areas which is subject to heavy restrictions, one of which is that use of the runway is prohibited between 11:00 pm and 6:00 am.

Last Sunday, the fortunately rare situation arose where the parallel runway system could not be used between 5:00 pm and 2:00 am due to high south easterly winds. During the period from 5:00 pm to 11:00 pm traffic could therefore only be operated from the cross runway which also had to be kept clear of snow. Between 11:00 pm and 2:00 am the above-mentioned restrictions on the use of the cross runway completely closed down all traffic. By 2:00 am the winds had changed so much that traffic could be resumed on the parallel runway system.

During a similar coincidence of circumstances on the night before Christmas Eve in 1994, the airport granted exemption from the restrictions to allow aircraft to use the cross runway after 11:00 pm. This decision provoked a sharply-worded reprimand from the authorities stressing that the rules were not to be deviated from.

Who is responsible for taking care of stranded passengers?

A large number of passengers stranded at the airport last Sunday. According to international agreements, the airlines are responsible for taking care of their passengers, and hotel accommodation was in fact arranged for most of them. Some airlines chose to leave their passengers at the airport, and we therefore asked the restaurants to stay open to ensure that food and beverages were available. As usual in such situations, the airlines handed out vouchers to be used as payment.

The airline industry has a set of internationally applicable rules adhered to in almost all parts of the world. These rules provide a precise description of who is responsible for what. The airport therefore cannot undo the decisions made by the airlines concerning, for example, hotel accommodation. However, the airport did book hotel rooms for passengers who did not want to stay overnight at the airport. One reason why some airlines kept their passengers at the airport until after 11:00 pm may be that they hoped to get them out quickly if the winds changed, and the other runway system could be used.

Why did the delays continue Monday?

The airport started off last Monday with major problems. The aircraft which had not left the airport the night before were blocking the way for aircraft approaching Copenhagen.

Why could the stranded aircraft not just take off? Because a chain reaction had been set off. For example, the Varig flight scheduled for Brazil Sunday evening could not take off, because the crew had run out of hours. The crew could not work again until Monday afternoon, and therefore Varig’s big MD-11 was blocking an aircraft stand until after 2:00 pm Monday afternoon. In normal circumstances, this stand could have been used for several aircraft during the day. A number of other aircraft were blocking aircraft stands in a similar manner to the great inconvenience of traffic to and from the airport.

"I deeply regret that many passengers had a bad experience at Copenhagen Airport, but I have nothing to blame my staff for. On the contrary. They handled their jobs to perfection, and if we had been allowed to let aircraft take off after 11:00 pm Sunday evening, the problems would never have escalated the way they did," says Niels Boserup, CEO of Copenhagen Airports.