What happened
On May 24, 2007, a Robin DR 400 / 180S, registration D-EKSR, was conducting a VFR flight from Győr/Per to Dresden. While flying at 3,500 ft on a heading of 355°, the aircraft entered the Prague TMA II airspace north of the Žebrák point without prior clearance. At the same time, a Boeing 737-500, registration OK-CGJ, operated by Czech Airlines, was performing an ILS/DME approach to runway 06 at Prague Ruzyně Airport.
The conflict was identified when the Tower controller (TEC) noticed an unidentified target on radar at 3,600 ft that conflicted with the flight path of CSA73C. Upon inquiry, the crew of the Boeing 737 reported receiving a TCAS Traffic Advisory (TA) involving unknown traffic approximately 3 NM from the final approach fix. Following this alert, the Prague Approach controller (APP PEC) identified the aircraft as D-EKSR and instructed the pilot to descend to 2,500 ft. The pilot of D-EKSR complied immediately with the instruction.
The investigation
The ÚZPLN investigation examined radar records, ATS communications, and pilot statements. The investigation focused on why the VFR aircraft entered the controlled airspace and why the air traffic controllers failed to identify the conflict sooner. The investigation also reviewed the pilot's pre-flight planning and the effectiveness of the radar display settings used by the approach controller.
Findings
- The pilot of D-EKSR failed to recognize the boundaries of TMA II Prague during both pre-flight planning and the flight itself, noting that the 1:500,000 scale ICAO chart used made reading the information difficult.
- The pilot entered TMA II Prague at 3,500 ft without obtaining the necessary entry clearance.
- The approach controller (APP PEC) was slow to identify the unauthorized traffic due to the unclear color differentiation of uncorrelated targets on the radar display.
- The Flight Information Service (FID) controller failed to notify the pilot of D-EKSR that they had entered the TMA II airspace.
- The approach controller failed to provide timely information regarding the significant traffic conflict involving CSA73C.