Incident Overview
On 29 May 2015, a Boeing 737-800 (B738) operating in the Warsaw Flight Information Region (FIR EPWW) violated active dangerous area EPD 24. The aircraft had reported to the GAT ACC sector at the FIR boundary between waypoints BODLA and ALUKA, and received clearance to fly directly to waypoint BOKSU. Approximately one and a half minutes before entering the active restricted zone (EPD 24, extending from ground to FL495), the controller noticed the situation and instructed the crew to turn left by 25 degrees. However, this maneuver did not prevent the aircraft from entering the airspace.
Timeline of Events
At 05:08:10 UTC, the crew of the B738 reported at flight level FL370 with a heading toward TOPUR and were cleared to proceed direct to BOKSU. At 05:14:00, a yellow ZN (danger area) alert appeared on the radar display. At 05:15:15, the controller ordered a left turn of 25 degrees to avoid EPD 24; the aircraft did not change heading immediately. At 05:15:50, the controller repeated the order using the word "immediately," and the aircraft began a left turn. At 05:16:10, a red ZN alert appeared on the radar display. At 05:17:30, the ZN alert turned off. At 05:18:05, the crew was cleared for own navigation to BOKSU.
Findings
The investigation found that the controller was on his second shift after one day off. The number of open sectors was appropriate, and traffic volume was at the upper limit. The controller held an ACS (Area Control Surveillance) license since 2008, with all current ratings and medical clearance, and had completed a refresher course in September 2014. By automatically clearing the B738 to fly directly to BOKSU, the controller had directed the aircraft toward the active EPD 24. The controller, occupied with traffic on the lower part of the radar display, did not notice the ZN warning for some time. The order to turn 25 degrees was insufficient to avoid the restricted area. Additionally, despite the controller informing the crew about the approaching dangerous area, the crew delayed executing the maneuver.
Cause
The incident was attributed to errors in air traffic management (ATM) work.