Many people had to change their travel plans, not least on Ekofisk and other Norwegian fields. Crew changes were suspended because helicopters could not fly.
The ash cloud from the volcano began to create problems for aviation from around 9 April. Norway’s whole airspace was shut on Thursday 15 April.
Anyone who wanted to travel had to turn to road, rail or sea – which was generally impractical over long distances. People were quite simply stuck where they were.
The worst problems lasted just under a week. According to the meteorologists, reduced emissions from the volcano meant suspended ash was largely lower than 4 500-5 000 metres. That put it below flight paths.
Particle sizes were also larger, which meant the ash would reach ground level before arriving in Norway or the UK. If that continued, conditions would be good within a few days.
On the basis of forecasts from Britain’s Meteorological Office, Norwegian airport operator Avinor announced on 19 April that most of Norway’s airspace was free of the ash cloud.
Air traffic was thereby restored. However, helicopters to and from Ekofisk remained grounded and other flights offshore were limited.
As the ash system was gradually blown westwards and dissipated, the position also improved over Ekofisk and helicopter traffic could be resumed.[REMOVE]Fotnote: NTB, “Størstedelen av luftrommet over Norge åpent”, 19 April 2010.Vessel collision with 2/4 WEkofisk 2/4 VA