Incident 1205/2020: Diamond DA20-C1 SP-NLN High Oil Pressure

Incident Overview and Aircraft Details On 14 May 2020, a Diamond DA20-C1 with registration SP-NLN was involved in an incident near Kutno, Poland. The event was recorded as Incident No. 1205/2020 by the State Commission for Investigation of Aviation Accidents (Państwowa Komisja Badania Wypadków Lotniczych). The aircraft was operating a cross-country flight when the pilot-in-command observed an abnormal increase in engine oil pressure during the second hour of flight. ## Operational Sequence and Contributing Factors During normal operation, the engine oil pressure for this aircraft is expected to remain between 30 psi and 60 psi. In this case, the pressure rose to between 70 psi and 85 psi, while the oil temperature remained within normal limits. The air temperature at departure was 11°C, and it was 13°C upon landing. The flight manual recommends installing engine cooling inlet covers when temperatures are below 12.5°C. The pilot did not install these covers before the flight. As a result, the engine oil did not reach its proper operating temperature, which increased its viscosity and led to the elevated oil pressure. ## Pilot Response and Outcome Upon recognizing the abnormal condition, the pilot informed Warsaw Flight Information Service (FIS WARSZAWA), interrupted the planned task, and proceeded directly to the airfield at Nowe Miasto. The pilot completed the approach and landed safely without further consequences. The aircraft was subsequently grounded for inspection to determine the cause of the incident. ## Investigation Findings and Safety Recommendations The investigation concluded that the high oil pressure was caused by the pilot's failure to install the engine cooling inlet covers. No contributing circumstances were identified. The commission accepted preventive recommendations proposed by the investigating entity, which included a detailed review of the incident with the instructional staff, civil and military students, and flight personnel. Emphasis was placed on the necessity of thorough pre-flight inspections and careful analysis of air temperature before flight, including consideration of its expected changes throughout the day. No additional safety recommendations were formulated by the commission.