What happened
On February 16, 2002, a Fokker 70, registration PH-KZH, operated by KLC, was performing a scheduled flight from Amsterdam to Torino Caselle. Following overnight parking, the aircraft underwent de-icing procedures. During the takeoff roll at Torino Caselle, the aircraft experienced a significant event involving the engines.
Shortly after rotation and liftoff, the crew encountered severe engine damage. The aircraft's systems triggered a series of warnings, including a cabin pressure alert. The crew declared a 'MAYDAY' and initiated an emergency return to the airport. During the climb, the right engine (engine No. 2) suffered severe damage, and the left engine (engine No. and 1) also experienced issues. The crew managed to execute an emergency landing at Torino Caselle. There were no fatalities or injuries reported among the crew or passengers.
The investigation
The ANSV investigation focused on the sequence of events from the pre-flight inspection through the takeoff and emergency landing. Investigators examined the de-icing fluids used, the maintenance history of the Rolls-Royce engines, and the aircraft's flight warning systems. The investigation also reviewed the organizational processes of the operator, KLC, specifically regarding de-icing procedures and resource management. Technical analysis included a reconstruction of the flight using a flight simulator and an examination of the digital flight data recorder (DFDR) and cockpit voice recorder (CVR) to understand the engine failure sequence and the crew's response to the cockpit warnings.
Findings
- The primary cause of the event was severe engine damage occurring during the takeoff phase.
- The investigation identified the formation of clear ice (glaze ice) as a factor related to the aircraft's condition.
- A critical technical issue was identified regarding the engine's fuel shut-off lever, which remained stuck in the open position following the attempt to mitigate engine damage.
- The crew was faced with complex cockpit warnings, including high vibration alerts on the remaining functional engine and cabin pressure alerts, which complicated the emergency management.
- There were findings related to the effectiveness of the de-icing/anti-icing procedures and the need for clearer technical information regarding engine failure procedures in the aircraft operating manual.