As winter approaches in many places, we wish to share best practices and experiences for safe operations from our home country of Finland. Winter conditions at airports in Finland can be very challenging from October to March when there is plenty of snow and ice. For safety reasons, pilots and air operators with limited experience in difficult winter conditions in northern Europe should read these instructions carefully.
Airport winter maintenance in Finland is at the top level and is internationally renowned for its know-how. However, the weather and surface conditions, especially at airports in northern Finland, can be very difficult. Besides runways, the taxiways and aprons may also be partly or entirely covered with snow and ice, but yet in an operable condition.
Airport conditions are reported in SNOWTAM messages
Airport movement area conditions are reported using a SNOWTAM message. Some of the most important issues to consider are listed below.
- Runway conditions reporting is based on Global Reporting Format (GRF). The Runway Condition Assessment Matrix (RCAM) is used in order to assign the RWYCC and for runway surface description. Reported RWYCC and contaminant type, coverage, and depth are based on the runway inspector’s overall assessment of the surface conditions. Measurements and sensor data may supplement visual observations.
- In SNOWTAM messages, the conditions are reported for each third of the runway, beginning from the smaller runway designator. In landing instructions provided by ATIS or the ATS unit, however, they are given in the direction of landing.
- SNOWTAM and ATIS messages may contain information regarding the removal of significant contaminants (TOSC) on the runway. The use of contaminant reported as take-off significant must be carefully considered and based on the operator’s own procedures regarding its operational utilization.
- When determining TOSC, the reporting system collects all contaminants reported on the runway and divides them into thin (none drag causing) and thick (drag-causing) contaminants with respect to airplane performance. The system reports TOSC as a piece of additional information, in compliance with an interpretation of the aircraft performance requirements specified by EASA CS-25, with supporting documents from regulation GM1 ADR.OPS.B.037(b) paragraphs b) and c).
Pilots are required to check the content and effect of SNOWTAMs before operating at airports in Finland. It is important to understand how the reported conditions actually affect flight operations. Air carriers must ensure that their pilots receive sufficient SNOWTAM training. The aim is to time runway maintenance according to the needs of air traffic. Flight planning must take into account the possibility that the conditions prevailing at take-off time may be significantly different from landing time.
So far there is no Specially prepared winter runway (SPWR) operations in Finland.
Up-to-date information on runway conditions is available from ATIS or the ATS unit. Airport maintenance actions can also be requested where necessary. Sand is not used in Finland to improve surface friction. The ATS unit and airport maintenance are there at the pilots’ service.
En-route and initial approach
Runway conditions and prevailing weather may vary. Whenever necessary, ask for the latest information directly from the destination airport in good time.
Airports may provide AFIS, radar service, or procedural ATC service. The effect of the service level on pilot responsibilities must be noted. At AFIS airports and airports with procedural ATC, for example, pilots are responsible for calculating any temperature corrections themselves. It is particularly important to take into account temperature corrections in cold winter conditions.
Aerodrome Flight Information Service (AFIS)
Some Finnish airports are not providing air traffic control service, but only have an AFIS unit that provides Aerodrome Flight Information Services. The AFIS unit reports any known traffic, and the pilot-in-command is responsible for maintaining safe distance to other traffic based on these reports and in compliance with the Rules of the Air. Pilots are also required to report their own intentions. The AFIS unit is responsible for the use of any necessary aerodrome equipment, and for controlling vehicle traffic.
Operational procedures for AFIS aerodromes are described in section GEN 3.3, paragraph 3.1 of the Aeronautical Information Publication, AIP Finland. Please read them before operating to any AFIS Aerodrome.
Approach and landing
To minimize the risk of runway excursion, it is essential to make sure that the approach is stabilized, especially when approaching a runway with Runway Condition Code RWYCC = 3 or lower. In some cases (available) runway width may be less than in AIP published nominal width. The decision on making a go-around must be made early in case of any signs of an unstabilized approach. It is also important to note that the touchdown zone markings may not be fully visible. When there are reported deposits (e.g. snow and ice) on the runway, friction may vary significantly along the runway length and, in some wind conditions, also between the left and right side of the runway centerline.
The pilots’ possible assessments of the runway condition (AIREP) must be reported according to the Runway Condition Assessment Matrix on a scale from good to less than poor.
Runways, taxiways, and aprons
Conditions on taxiways and at the apron may differ from those on the runway, usually in the lower direction. Taxiway and apron conditions are only reported when conditions are assessed slippery, poor, or less than poor. Under such conditions, utmost caution shall be taken when maneuvering the aircraft. Note that there is normally snow and ice on the taxiways and aprons, and they can be slippery. In such conditions, it is especially important to prepare for any movements or changes well in advance. At some airports, the apron or aircraft stands may be on sloping ground, which means that parking brakes must be used. Check the need for using brakes from airport ground services.
It is important to note that freezing temperatures may affect brakes and other aircraft devices.
Passengers must also be warned that the apron may be slippery.
De-icing and anti-icing
In winter, operators must identify the possible need for aircraft de-icing on the ground, make sure that de-icing services are available, and verify that their aircrews are appropriately trained also for de-icing operations on the ground.
Under challenging winter conditions, proper deicing is an essential element of flight safety. When there is reason to suspect that frost, ice, or snow is adhering to aircraft surfaces, the need for de-icing must be determined. This must be done from a point offering good visibility of the aircraft surfaces. Once the need for de-icing has been determined, the pilot-in-command is responsible for deciding whether de-icing treatment is necessary.
The ‘Clean Aircraft Concept’ ensures safe flight operations. In all operations, the pilot-in-command is responsible for assessing whether the airplane is safe. The aircrew and ground or maintenance personnel must still report anything that may affect flight safety. Open communication is vital, and all matters affecting airworthiness must be communicated to the pilot-in-command in a clear and brief manner.
It is crucial that the airplane must not take off if the pilot-in-command has not been able to assess whether the airplane is free of frost, ice, and snow. This requirement can also be met by having the airplane checked by personnel with relevant training and ratings.
Any contamination observed before a flight can be removed by applying a hot de-icing fluid that will melt and flush off ice and snow deposits. Moreover, anti-icing fluid may be sprayed on critical surfaces before take-off to prevent new formations of frost and ice.
The pilot-in-command must check the hold-over times of de-icing fluids from the tables available. It is important to ensure a ‘Clean Aircraft Concept’ also during departure taxing and take off.
Have a safe flying season and welcome to airports in Finland!
This information leaflet was drafted jointly by Finavia Corporation, Lappeenranta, Enontekiö, Mikkeli, and Seinäjoki airports, Finnair, Norra, Fintraffic ANS, Finnish Meteorological Institute and the Finnish Transport and Communications Agency (Traficom), which is the civil aviation authority of Finland. The original leaflet can be seen here: https://www.traficom.fi/sites/default/files/media/file/Winter_Operations_Bulletin_2022.pdf
Edit 13th of February 2023: Corrected an incorrect reference to EU-OPS to EASA CS-25, with supporting documents from regulation GM1 ADR.OPS.B.037(b) paragraphs b) and c).