The ANSV has finalized investigations into three separate aviation occurrences involving different aircraft types and flight operations.
What happened
On December 16, 2000, an Alitalia Team McDonnell Douglas MD-82, registration I-DAVT, experienced a left engine flame-out during the initial climb phase at Naples Capodichino Airport. The crew declared an emergency and successfully returned to the airport for a landing.
On October 27, 2002, a Cessna 120, registration I-FFLJ, performing a recreational flight near Castelluccio di Norcia, experienced engine power loss at an altitude above 5,000 feet. The pilot performed an emergency landing in a field at Pian Grande.
On December 19, 2002, an ASK 21 glider, registration I-PAIS, operated by Aero Club Torino, sustained damage to its tail section during landing at Torino Aeritalia Airport. The aircraft had taken off while still attached to a ground handling dolly, which struck the terrain during the landing sequence.
The investigation
Regarding the MD-82, investigators examined the engine's P&D valve and found a significant external fuel leak. Technical tests conducted by Fiat Avio analyzed the valve cover under operating pressures.
For the Cessna 120, the investigation focused on engine performance and spark plug condition. The investigation revealed that the engine was running irregularly at high power settings but could maintain idle. Post-flight inspections of the engine found heavily fouled spark plugs and the use of incorrect copper gaskets.
In the case of the ASK 21, the ANSV examined the pre-flight inspection procedures and the operator's reporting timeline. The investigation noted that the aircraft was sent for repairs to a certified workshop before the authorities were notified, which hindered the official investigation process.
Findings
- The MD-82 engine failure was likely caused by a maintenance error involving the over-tightening of two closing nuts on the P&D valve filter cover, which damaged the valve body's threaded seat.
- The Cessna 120 engine instability was attributed to the pilot's failure to use the carburetor heat system at high altitudes, compounded by technical factors including fouled spark plugs and the use of improper gaskets.
- The ASK 21 damage resulted from an incomplete pre-flight inspection, which failed to identify that the ground handling dolly was still attached to the tail boom.
Safety action
- The ANSV issued a recommendation (ANSV-7/208-1/I/03) to ENAC to increase oversight of recreational aviation operators regarding the use of non-standard parts, specifically regarding improper gaskets.
- For the ASK 21 incident, the agency recommended (ANSV-8/217-1/I/03) that ENAC and the Aero Club d'Italia sensitize operators to the importance of using checklists to ensure thorough pre-flight inspections.