What happened
On October 10, 2019, at 12:15 UTC, the crew of a Diamond DA-20, registration SP-NDE, departed from Dęblin Airport (EPDE) to perform a flight mission in accordance with their filed flight plan. During the flight, the crew maintained communication with their own flight center's flight manager.
At 12:25 UTC, military aircraft operations resumed at Dęblin, maintaining contact with Dęblin Tower (TWR). However, the crew of SP-NDE was unaware that Dęblin TWR had resumed operations at 12:45 UTC. Consequently, the aircraft entered the Dęblim MCTR airspace without establishing radio contact with the tower. Despite the crew's attempts to establish communication on various frequencies, they failed to announce their presence and continued their mission as planned. The flight eventually returned to the departure airfield and landed without further incident.
The investigation
The investigation focused on why the crew failed to establish contact with Dęblin Tower despite the resumption of air traffic services and why the aircraft entered the controlled airspace without communication.
Findings
- The primary cause of the incident was the lack of radio communication caused by a malfunctioning transmission button on the aircraft's radio equipment.
- The crew failed to notice the visual light signals being transmitted from the Dęblin Tower.