Aircraft noise

In connection with winter maintenance (snow removal) at the airport, Oslo Airport uses state-of-the-art equipment to brush and blow away the snow. The vehicles, powered by large diesel engines, usually operate in a group around the airport, which results in some noise.    

Sound propagation in air depends on, among other things, humidity, temperature, and wind direction. For instance, if there is a strong westerly wind, you will be able to hear the planes better than usual in Jessheim, which is located east of the airport. Similarly, when the wind is from the east, they can be heard better than usual in Nannestad.

When the air is humid and foggy, sound will propagate faster than normal and reach further. Under inversion conditions, where air temperature increases with height instead of decreasing, sound sources on the ground can be heard better than normal at ground level in the surrounding area.

When airplanes land, there is a kind of engine reverse that helps slow down the plane after landing. In practice, a "shield" is deployed behind the engine to direct the jet stream from the engine forward (instead of backward, which provides propulsion). Together with the airplane's wheel brakes, this helps reduce the plane's speed after landing. The current route regulation states the following about the use of such reversing: During the night period, reversing of jet engines beyond "idle reverse" after landing is not permitted. (Editor's note: idle reverse - reversing with the engines at idle speed)

This is a Jumbo Jet that transports, among other things, salmon to Asia. Normally, this plane carries over 100,000 kg of salmon. The plane weighs 180 tons and also carries 100 tons of fuel. With cargo and fuel, the plane weighs closer to 400 tons. Due to the weight, it climbs relatively slowly. The size and noise level make the altitude, as perceived from the ground, seem lower than for smaller planes at the same altitude.

These are helicopters from the Norwegian Air Ambulance with a base at Akershus University Hospital in Lørenskog. On emergency missions, they want to fly the shortest route, and to reach the hospital in Elverum or Hamar, for example, they pass right over Jessheim. Helicopters heading to Lillehammer often fly over Nannestad. To avoid conflict with commercial flights flying in and out of Oslo Airport, they fly relatively low in this area.  

The jet engines on airplanes emit a large amount of water vapor. When they leave a white trail in the sky, they are normally over 10 km above the ground. Up here, it is cold, often below minus 50 degrees. Therefore, this water vapor turns into ice crystals that form the white trails in the sky. If you are in Romerike and see such a contrail, this plane is not heading to Oslo airport. Instead, it could be a plane flying from Stockholm to New York if you see it flying from east to west, or possibly a plane on the London-Tokyo route if you see it flying from south to north.  

Peak or in Norwegian; "topp", is a term used in aviation to describe the times during a day when the number of flight movements approaches the maximum that an airport handles. At Gardermoen, there is a typical peak between 8:00 AM and 9:00 AM from Monday to Friday. During this time, traffic usually reaches 65 flight movements per hour (approximately 30 landings and 35 departures), but there can be more traffic than this. In the summer of 2014, we had a day with 78 flight movements in one hour.

It is mostly the wind direction that determines which runway is used at Gardermoen. However, it is not only the surface wind, but also the wind at altitude that is considered when evaluating the runway for takeoff/landing. Aircraft prefer to take off and land into the wind as much as possible. If the wind blows from the south, the aircraft will mostly land from north to south and take off southward. Conversely, when there is a northerly wind, the opposite will be the case.

Here you can find the outline of the corridors on a map background. This is an attachment in the current regulation on noise prevention for Oslo Airport. 

For safety reasons, all pilots want to avoid convective clouds (thunderclouds and heavy rain showers, technically known as cumulonimbus). Air traffic controllers always alert pilots of such conditions and allow deviations around areas with these clouds. During periods of stormy weather, there may therefore be flights over densely populated areas where overflight is normally avoided (Jessheim, Sand, Kløfta, Maura). 

In the Regulations on Noise Prevention for Oslo Airport, § 3, it states that flights with fighter jets and military flights for testing or training purposes (including landing circuits) are exempt from the regulation.

At the northern end of the airport, the Armed Forces have their own air station where their Hercules C130 transport aircraft are based. These are heavy propeller-driven aircraft with four propellers. Except in the exceptional cases mentioned above, these aircraft are subject to the same rules as jet aircraft upon arrival and departure (the regulation’s appendices 1 and 2).