Forced Landing of Piper PA-18-150 EC-JEC at Mollet de Vallés

Incident Overview and Flight Details On 28 August 2011, a Piper PA-18-150 with registration EC-JEC, operated by AIRCAT, departed Sabadell Airport at 11:32 local time for a commercial banner-towing operation along the Costa Brava. Weather conditions were suitable for visual flight rules, with light cloud cover and calm winds. The aircraft was powered by a Lycoming O-320-A2B engine. ## Engine Malfunction and Emergency Response Approximately 20 minutes into the flight, the pilot reported hearing loud detonations from the engine and experiencing a loss of power. The pilot contacted air traffic control, who authorized a return to the aerodrome at the pilot's discretion. The pilot subsequently informed controllers that the aircraft could not reach the aerodrome and elected to land in a nearby field. ## Forced Landing and Aircraft Damage The pilot first selected a clear field and released the banner. The aircraft then approached a field in Mollet de Vallés, northeast of the airport, from an altitude of 1,200 feet at approximately 60 mph. Near the ground, the pilot identified previously undetected obstacles and executed a right turn to an adjacent field. The aircraft touched down heading north in plowed terrain with north-south furrows. During landing, the aircraft cartwheeled and came to rest inverted with the vertical stabilizer embedded in the ground. The pilot was uninjured, and the aircraft sustained major damage. ## Pilot and Aircraft Maintenance Background The 26-year-old pilot held a commercial pilot license (CPL(A)) with multi-engine and instrument ratings, and had 353:47 total flight hours, including 42:55 hours on type. The aircraft, manufactured in 1957, had 2,496:40 flight hours and had passed all required maintenance inspections. The last inspection was conducted on 28 June 2011. ## Investigation Findings Engine inspection revealed that the left magneto was defective, failing to supply proper current to three of four spark plugs. Additionally, two spark plugs fed by the right magneto were in poor condition due to insufficient electrode separation and carbon buildup. The right magneto also showed signs of defective operation, including irregular platinum contacts and distributor cap damage. These combined failures caused the engine detonations and power loss. The investigation concluded that these defects were likely not corrected during maintenance inspections, despite the aircraft passing all required checks. ## Contributing Factors The presence of undetected obstacles at low altitude prevented the pilot from landing in a more suitable field. The poor condition of the terrain in the selected field contributed to the aircraft cartwheeling and increased damage. The pilot's decision to release the banner and select a field was considered appropriate given the circumstances.