What happened
Between June and September 2023, a series of air traffic conflicts occurred during landing patterns at Arendal Airport Gullknapp (ENGK). These incidents involved training aircraft from OSM Aviation Academy (OSMAA) and various general aviation aircraft. In one notable event on September 13, 2023, a Cessna 172 (registration LN-AZE) and another Cessna 172 (SE-LZO) were performing training maneuvers when a third aircraft, a JMB Aircraft VL-3 Evolution (LN-YBV), entered the pattern. The pilot of LN-YBV believed they had successfully transmitted position reports, but the lack of response from other aircraft led to a situation where the student pilot in SE-LZO had to perform an emergency go-around to avoid a collision.
Other incidents during this period also required evasive maneuvers to prevent more serious outcomes, highlighting a recurring pattern of traffic conflicts in the landing pattern.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the safety framework at the airport, specifically looking at the period between 2018 and 2023. The investigation focused on the impact of the flight school establishing its base at the airport and the subsequent changes in airport services. The NSIA reviewed flight movement increases, noise analysis reports, and the decision-making processes involving the airport, the flight school, the Norwegian Civil Aviation Authority, and the Ministry of Transport. The investigation also looked into the technical aspects of the incidents, such as radio communication failures and the effectiveness of ground-based monitoring.
Findings
The investigation established that the primary cause of the increased risk was the combination of significantly increased flight traffic and a reduced level of air traffic services. In 2021, the airport discontinued its Aerodrome Flight Information Service (AFIS) for economic reasons, which meant IFR operations were no longer permitted.
Key contributing factors included:
- The decision to increase flight movement licenses did not sufficiently weigh safety against other operational or economic considerations.
- There was a lack of adequate oversight and attention to flight safety by the flight school, the airport, and national aviation authorities during the expansion of activities.
- Technical issues, such as a damaged headset plug in LN-YHD, contributed to a pilot's inability to confirm two-way radio communication.
- Ground monitoring was insufficient, as the Ground OPS instructor was unable to monitor multiple frequencies simultaneously due to equipment failure.
Safety action
Following the investigation, the Norwegian Civil Aviation Authority ordered Arendal Airport Gullknapp to investigate the necessity of re-establishing air traffic services and to provide an updated safety assessment. In June 2024, the airport concluded that AFIS must be re-established to maintain an acceptable level of safety. The NSIA has issued safety recommendations to both the Ministry of Transport and the Norwegian Civil Aviation Authority to review the regulations regarding the awarding of airport licenses to ensure that safety is prioritized over other interests.