Introduction
On August 8, 2022, at 08:39 local time (05:39 UTC), a Partenavia P.66C "Charlie" aircraft with registration LZ-PTS, operated by a pilot-owner, suffered an accident near the village of Krushevets, Bulgaria. The flight had departed from Primorsko Airfield at 08:24 on an en-route flight to Bohot Airfield.
Flight History
About nine minutes after takeoff, during climb, the pilot observed a drop in oil pressure. He informed the Flight Information Center (FIC) and initiated a reverse course back to Primorsko Airfield. As oil pressure continued to decrease, the pilot decided to conduct a forced landing at a site selected from the air in the territory of Krushevets. During the final approach, just before touchdown, the aircraft contacted a wire fence that was not noticed during the approach. After landing, the aircraft nosed over.
Injuries and Damage
The pilot sustained a laceration on the head with bleeding. The aircraft received significant damage to the airframe and the propeller was destroyed.
Investigation Findings
The investigation commission identified two immediate causes:
- The oil filler cap of the aircraft engine fell off due to failure to close and lock it during the preflight inspection by the pilot-owner.
- The pilot did not identify the site fence when landing at the selected site.
Additionally, the commission noted several concomitant reasons that contributed to the accident:
- The pilot performed elements of line maintenance for which he had no authorization.
- The pilot used a checklist for normal and emergency procedures in Italian, a language he did not speak.
- A poor-quality and non-approved translation of the Aircraft Flight Manual (AFM) was used.
- The approved documentation (AMM and AFM) was only available in Italian.
- Inadequate control by the Directorate General of Civil Aviation Authority (DG CAA) during annual airworthiness inspections.
- Ineffective functioning of the search and rescue system for aviation accidents.
Conclusion
The accident resulted from a combination of preflight oversight and landing site misjudgment, compounded by several systemic and procedural deficiencies as detailed in the investigation report.