What happened
On June 19, 2006, at approximately 12:29 UTC, a serious near mid-air collision occurred approximately 8 km southeast of Benešov Airport (LKBE). A Z 142, registration OK-LNB, was conducting a training aerobatic flight. The pilot had notified the Benešov AFIS of the intention to perform maneuvers in the airspace below FL 075, specifically climbing to FL 070.
Simultaneously, a Cessna C 182, registration OE-BAX, was operating an IFR flight from Prague-Ruzyně (LKPR) to Vienna (LOWW). While navigating the VOZ VOR inbound at FL 070, the pilot of the C 182 decided to change course to avoid cumulonimbus (CB) clouds. During this maneuver, the pilot observed the Z 142 performing a near-vertical climb through clouds. The aircraft was extremely close, at a distance of only 150 to 200 meters, and disappeared from the pilot's view for several seconds before being spotted again in a rapid nose-down descent.
The investigation
The ÚZPLN investigation established that the pilot of the Z 142 performed the flight at FL 070, which is an altitude that should not be used for VFR flights above the transition altitude. Furthermore, the investigation confirmed that the Z 142 was not equipped with an SSR transponder, despite the flight occurring above FL 060.
Findings
- The pilot of the Z 142 violated regulations by conducting a flight above FL 060 without an SSR transponder.
- The flight altitude of FL 070 is unsuitable for VFR operations above the transition altitude.
- The pilot of the Z 142 operated the aircraft without the required secondary surveillance equipment for the altitude reached.
- The pilot of the C 182 was operating on an approved IFR SID and his actions did not contribute to the incident.