Accident Overview
On 14 September 2018, a Piper PA-22 Tripacer, registration LV-IDL, departed from Brigadier General Antonio Parodi International Airport in Esquel, Chubut, at 19:30 UTC. The aircraft was conducting an aerial advertising flight over the city. Approximately one hour into the flight, at around 20:30 UTC, the engine experienced a power loss that prevented the aircraft from maintaining level flight. The pilot executed an emergency landing in an unprepared field. The accident occurred during daylight hours in good weather conditions. The aircraft sustained substantial damage, and the sole occupant, the pilot, reported no injuries.
Investigation Findings
The investigation determined that the spark plug on cylinder No. 3 had become loose due to the fracture of a threaded adapter (niple). This adapter was not a certified aeronautical component. The last 100-hour engine inspection had been performed in June 2018 at the Ezpeleta maintenance facility, during which the spark plugs were inspected and tested with no anomalies noted. The technical representative stated that the adapter had not been installed by that facility.
The complete maintenance history of the aircraft and engine was not available to investigators. Additionally, the aircraft was not equipped with an Emergency Locator Transmitter (ELT), which was non-compliant with Argentine Civil Aviation Regulations (RAAC) Part 91.
The flight was conducted as aerial work (advertising) by a private owner. The operation was performed without an Aerial Work Operator Certificate (CETA), as required by regulations. The pilot's remuneration consisted of flight time logging for the campaign.
Probable Cause
The investigation concluded that the engine power loss was caused by the breakage of a non-aeronautical threaded adapter on the spark plug of cylinder No. 3. The use of an uncertified component led to the failure and subsequent forced landing.