Previously, Turkish citizens were not required to have an Airport Transit Visa if they were only passing through the transit zone at Oslo airport, but this has now changed.
If you are a Turkish citizen who is planning to transit in Oslo airport after 23 August, and you do not already have a valid visa to the Schengen area, you must apply for an Airport Transit Visa. You do this by applying for a normal visitor’s visa and hand in documentation of your tickets, the purpose of your stay in your final destination and visa or residence permit in your final destination country or next transit country.
This has been decided by the Ministry of Justice and Public Security. The reason is the increase of Turkish citizens seeking asylum in Norway.