Factual Information
On 1 November 2016, at approximately 15:30 UTC, a serious incident occurred at Brno/Tuřany Airport (LKTB) involving two Cessna 152 aircraft. The aircraft with registration OK-MMB, owned by MS TRANS, a.s., and OK-FAB, owned by Flying Academy s.r.o., were both conducting VFR training flights. Runway 27 was in use.
The air traffic controller (ATCo) on the TEC position had been on duty since 15:20 and had previously detected repeated splitting of radar targets on the TR-7 display, which was reported to the technical staff. Consequently, the controller relied primarily on visual reference, which was possible due to good weather conditions. The ATIS information Mike at 15:31 indicated wind 210° at 5 knots, visibility CAVOK, temperature 12°C, dewpoint 7°C, QNH 1018 hPa.
The communication between the controller and the pilots was recorded. The controller communicated with OK-MMB in Czech and with OK-FAB in English. OK-MMB was on a training circuit and was instructed to extend downwind to allow a helicopter to land. OK-FAB, coming from the northern area, was instructed to proceed to long final for runway 27. Later, OK-MMB was cleared to land and instructed to vacate via taxiway W. The controller then cleared OK-FAB to land, instructing vacating via taxiway D. However, at the time of the clearance, OK-MMB had not yet vacated the runway. OK-FAB landed on the occupied runway, and subsequently vacated via taxiway C instead of D, contrary to the instruction.
No injuries or damage were reported. The runway was dry and clean.
Analysis
The radar system had a malfunction that caused splitting of targets, prompting the controller to rely on visual separation. The pilot of OK-FAB shortened the approach path and flew at a higher speed (approximately 120 knots) compared to OK-MMB (approximately 80 knots), reducing the distance between the aircraft. OK-MMB landed without its landing light on, while OK-FAB had its landing light on; this likely affected the assessment of the actual separation. The controller issued landing clearance to OK-FAB without confirming that OK-MMB had vacated the runway. After checking, the controller realized OK-MMB was still on the runway but did not issue a go-around instruction. The pilot of OK-FAB could probably see OK-MMB on the runway but still landed. The foreign pilot likely did not understand the Czech communication between the controller and OK-MMB.
Conclusions
The cause of the serious incident was the issuance of landing clearance onto an occupied runway. The operator of air traffic services (ŘLP ČR, s.p.) implemented corrective measures, including relieving the controller, subsequent training, and familiarization with the incident report. The investigation authority (ÚZPLN) did not issue safety recommendations.