What happened
On February 20, 2008, a Tecnam P92-JS, registration OK-RWY, was performing a banner tow flight along a route between Benešov and Litomyšl. During the flight, the pilot contacted Prague ACC to inquire about the activation status of specific temporary reserved areas (TSA 26 and TSA 27). Having been informed that those specific areas were not active, the pilot proceeded with a flight path designed to bypass the Čáslav Control Area (MCTR Čáslav) by flying at an altitude below 300 meters above ground level.
However, while navigating the area near Chotěboř, the aircraft entered the active TSA 20 airspace without establishing communication with the relevant air traffic control unit. Radar monitoring by Prague ACC identified the aircraft approaching the boundary of the Čáslav Control Area. Upon checking with Čáslav Approach, controllers noted that the aircraft was not in contact and was approaching the active TSA 20, where military aircraft departures were expected. The aircraft continued through the restricted airspace, flying at altitudes between 2,100 and 2,300 feet (pressure altitude), before exiting the Čáslav airspace boundaries near Seč.
The investigation
The ÚZPLN investigation examined radar records, audio recordings, and operational documentation. The investigation focused on the pilot's flight planning and the communication between the pilot and air traffic services. The inquiry established that the pilot had inquired about other TSAs but had failed to account for TSA 20 in the flight preparation. The investigation also reviewed the actions of the air traffic controllers at Prague ACC and Čáslav Approach, noting that they monitored the aircraft via radar and attempted to establish contact.
Findings
- The pilot failed to notice the existence of TSA 20 during flight preparation due to inattention to the aeronautical charts.
- Because the pilot was unaware of the TSA 20 requirement, they did not seek information regarding its activation status.
- The pilot maintained an altitude intended to avoid the lower vertical limits of the Čáslav Control Area but inadvertently entered the vertical limits of TSA 20 (300 ft to 1,000 ft AGL).
- The pilot did not establish two-way communication with the appropriate air traffic control services while transiting the restricted area.
- Air traffic controllers monitored the unidentified traffic via radar and, upon realizing the potential conflict, delayed military departures to maintain safety margins.
- The pilot held a valid CPL(A) license and was qualified for the aircraft type.