What happened
On January 16, 2020, a Zlín Z-42 M, registration OK-ALC, was performing a planned circuit flight at Brno Tuřany Airport. After receiving takeoff clearance from the tower for runway 27, the aircraft climbed to approximately 50 meters. Shortly after liftoff, the pilot detected a burning sensation and observed smoke entering the cockpit.
The pilot immediately declared a "MAY DAY" and requested an emergency landing. Following instructions from the tower, the pilot performed a 18-degree turn to align with runway 09 and landed safely. The aircraft taxied to taxiway B, where the engine was shut down and the fuel supply closed. Airport fire services arrived promptly to inspect the aircraft. While no active fire was found on the exterior, a strong smell of smoke and burning was present inside the cabin.
The investigation
The ÚZPLN investigation focused on the source of the smoke and the potential for fire within the engine compartment. Upon inspection of the engine cowling, investigators discovered that a plastic deflector from the left cooling air intake had become detached. The component had fallen into the lower left section of the engine compartment, where it came into contact with the exhaust pipe behind the silencer.
Findings
- The plastic deflector had become unfastened, likely during taxiing.
- The detached component fell onto the exhaust pipe, where the high temperatures of the takeoff phase caused the thermoplastic material to melt.
- The melting process released toxic fumes (including hydrogen chloride and carbon monoxide) and smoke into the cockpit.
- The pilot's rapid response and decision to land immediately prevented the melting plastic from potentially igniting and causing an engine compartment fire.
- There were no injuries to the pilot and no further damage to the aircraft beyond the destruction of the deflector.