Thousands of military personnel will take part in the Finnish Air Force's Ruska 20 drill, which is seen as the highlight of this year.
The week-long drill, which ends on 6 October, is meant to test and enhance the Air Force's preparedness, provide training for active duty members, conscripts as well as reservists.
"Ruska 20 will demonstrate the high readiness of the Air Force in protecting the integrity of Finnish airspace, and securing the functions vital to our society on a 24/7 basis in all situations. Active-duty personnel, conscripts and reservists operate in their emergency conditions' tasks as per the Air Force's mobile battle concept", Colonel Juha-Pekka Keränen, the commander of the drill, said in a statement.
Overall, more than 60 aircraft and close to 5,000 personnel, including roughly 2,500 reservists will take part in the exercise stretching over much of Finland and involving bases in the municipalities of Rovaniemi, Jyväskylä, Oulu, Kajaani, and Halli. As per tradition, the Swedish Air Force is also taking part in the Finnish Air Force's biggest exercises of the year.
The majority of the 60 aircraft are F/A-18 Hornet multi-role fighters, but the Swedish Air Force's JAS 39C/D Gripen multi-role fighters and airborne early warning and control (AEW&C) aircraft will also take part.
The exercises are to feature low-level flight missions, and supersonic F/A-18 Hornet flights. The aircraft will utilise countermeasures such as flares and chaff, which, it warned, may affect locals.
The Finnish military has adjusted its training routines to accomodate the ongoing COVID-19 epidemic.
"During the drill, we will observe national, regional, and local COVID-19 restrictions. The Finnish Air Force follows the development of the COVID-19 situation, and we are prepared to modify the arrangements of the exercise at short notice, if necessary", Keränen said.
He stressed that while live exercises of such calibre as Ruska are of paramount importance for testing the skills and readiness of troops, health and safety are a priority.
The most intensive part of the drill will take place from 2 to 6 October and feature additional airfields.