Avoidance of similar radio calls between different aircraft Recommendation status Implemented Investigation Branch Aviation L Type of Accident Accident Issue date 25.3.2020 Recommendation ID 2020-S8 Recommendation The Finnish Air Force develop clearly distinguishable aircraft callsigns for its exercises. Investigation report L2019-04 Serious incidents in the vicinity of the Jyväskylä airport in the morning of 5 April 2019