ANSV Investigation Reports: MD-82, Cessna 120, and ASK 21 Incidents (I-FFLJ)

Overview of the Investigation Reports The National Agency for the Safety of Flight (ANSV) issued a consolidated publication containing investigation reports for three civil aviation events. The reports were deliberated by the Agency's Board on October 30, 2003. The publication presents a synthetic form of the reports, while the complete documentation is preserved in the Agency's archives. The investigations were conducted in accordance with Annex 13 to the Convention on International Civil Aviation and Italian legislative decree 66 of February 25, 1999. The primary objective of the technical investigations is to prevent accidents and incidents, excluding any evaluation of fault or responsibility. ## MD-82 Incident at Naples Capodichino An investigation was opened on December 17, 2000, for an event initially classified as a serious incident involving a McDonnell Douglas MD-82, registration I-DAVT. The event occurred on December 16, 2000, at 19:05 UTC at Naples Capodichino Airport. During the initial climb after takeoff for scheduled passenger flight AZ 1850 to Palermo, the left engine experienced a flameout at flight level 120. The crew declared an emergency at 19:42 and requested an immediate return to the airport, landing regularly at 20:25. The operator was Alitalia Team. The aircraft was a 1989 model with construction number 1597, powered by two Pratt & Whitney JT8D-217 A engines. The crew consisted of a commander and co-pilot, both Italian males with valid ATPL licenses. No injuries or damage to persons or property were reported. The analysis indicated that around 19:36, the crew noticed a drop in parameters and loss of thrust from the left engine. Despite advancing the throttle, the EPR, EGT, N1, N2, and oil pressure continued to decrease until the engine stopped completely two minutes after the problem began. After landing, technical personnel detected a significant external fuel leak from the P&D valve (pressurization and drainage valve) of the left engine. The probable cause was identified as a maintenance error, specifically the over-tightening of two nuts closing the filter cover of the P&D valve, which damaged the threaded seat of the valve body. The Agency noted that the maintenance company had already implemented procedural modifications to prevent recurrence and decided not to issue specific safety recommendations. ## Cessna 120 Serious Incident in Castelluccio di Norcia A serious incident involving a Cessna 120, registration I-FFLJ, occurred on October 27, 2002, at approximately 08:30 UTC at Pian Grande, Castelluccio di Norcia (PG). The event involved a loss of engine power followed by an emergency landing. The operator was a private individual, and the flight was for tourism purposes. One person was on board, and no injuries or damage were reported. The pilot was a 49-year-old Italian male with a valid private pilot license, with 97 total flight hours, 52 on type, and approximately 18 hours in the last 90 days. The aircraft was a single-engine high-wing with a Teledyne Continental C 85-12F engine of 76 HP, holding a special flight permit (CNS) number 14173/S. The aircraft took off at 08:00 UTC from the S. Anna airfield in Montecassiano (MC) for a tour to the Monti Sibillini National Park, with a planned return to the departure airfield. At approximately 08:30 UTC, after contacting the Falconara TWR, the engine exhibited irregularities at 2,350 RPM at an altitude above 5,000 feet, north of Castelluccio di Norcia. The engine tended to stall at full power but could be maintained at idle at 1,900-2,000 RPM without issues. Oil pressure and temperature were within limits. The pilot decided to make a precautionary emergency landing at a field below (Pian Grande). The aircraft sustained no damage. The pilot reported that in the month prior, the aircraft had completed four flights above 5,000 feet without using the mixture corrector without any irregularities. On the day of the event, the pilot did not use the carburetor lean system, but due to different weather conditions (temperature and humidity), a loss of engine RPM occurred. Two days later, the engine functioned regularly without maintenance interventions, reaching maximum ground RPM (2,200 RPM) and showing acceptable drop at the magnet test (1,800 RPM). Inspections revealed that the spark plugs were excessively fouled, particularly the 1 up, 2 down, and 3 down, which were also fouled externally. The copper gaskets of the externally fouled plugs had a flat face (unsuitable for spark plugs), while the others had a convex face (appropriate for spark plugs). The immediate cause was identified as the incorrect and delayed use of the carburetor lean system at altitudes above 5,000 feet (human factor).