Incident Overview
On December 20, 2024, at 21:56 UTC, a Tecnam P92E MKII (registration LV-S130) was conducting a general aviation transfer flight from Rivadavia/Aerotec Aerodrome (Mendoza Province) to Cruz Alta Aerodrome (Córdoba Province). During the en route phase, the pilot detected a smell of burnt oil and observed a decrease in oil pressure indication. Following the aircraft's standard procedures, the pilot identified the nearest suitable aerodrome, notified air traffic control, declared an emergency, and performed an uneventful landing at Mercedes Aerodrome (Villa Mercedes, San Luis Province).
Maintenance Findings
The following day, personnel from Taller Air Andes SRL (TAR 1B-344) examined the aircraft at the aerodrome. They determined that the oil pressure loss resulted from the absence of an M8x20 Allen screw (part number 240072) and an A8x13 seal ring (part number 950141). The screw had not been properly tightened during its installation; combined with engine vibrations, it progressively loosened, unscrewed, and detached. This allowed pressurized oil to leak from the engine, causing the pressure drop.
Inspection and Return to Service
Maintenance actions included cleaning the aircraft, draining the oil circuit, inspecting the oil filter and magnetic particle detector, performing a borescope inspection, and measuring crankshaft rotation resistance. After confirming no engine damage had occurred, a 45-minute test flight at various RPM settings was conducted. The aircraft was then cleared for return to service by TAR 1B-344.
Aircraft and Personnel Information
The aircraft, a Tecnam P92E MKII (serial number 1646), is an ultralight fixed-wing category with a maximum takeoff weight under 2,250 kg. It sustained no damage. The pilot, a 54-year-old male holding a private pilot license issued by Argentina, was the sole crew member. The operator was a private owner conducting non-commercial, non-scheduled operations.