What happened
On June 27, 1998, at approximately 15:00 UTC, a Robin DR 400-180, registration F-GCAY, departed from the Beaune airfield for a local flight. Shortly after takeoff from runway 21, witnesses observed the engine RPM drop significantly. The aircraft subsequently veered to the right and began a descent, ultimately crashing into a ditch located approximately 300 meters from the end of the runway.
The accident resulted in two fatalities and left the pilot and one other passenger injured. The aircraft was destroyed in the impact.
The investigation
Investigators examined the wreckage and found the aircraft positioned in a ditch on the right side of the runway. The investigation of the Lycoming P-360A3A engine revealed no mechanical failures within the engine itself. However, inspectors discovered that a 5 cm² flake of paint had detached from the interior of the carburetor air intake box and become lodged in the carburetor venturi.
The air intake box, which had been installed as a new spare part only 50 hours prior to the accident, was found to have a coating issue. Chemical analysis of the paint showed that the intermediate primer layer lacked sufficient hardener, which resulted in almost zero adhesion between the primer and the final topcoat.
Findings
- The engine failure was caused by the obstruction of the carburetor venturi by a paint flake.
- The paint flake detached from the air intake box because the primer layer was improperly prepared with an insufficient amount of hardener.
- The pilot's management of the engine failure was inadequate, leading to a loss of control of the aircraft.
- The manufacturing defect was undetectable during standard inspections because the adhesion strength of the internal coating was not a controlled metric during the painting process.
Safety action
Following the investigation, the BEA recommended that the SFACT issue a safety directive to inspect the condition of the paint inside the carburetor air intake boxes on Robin aircraft. Additionally, the BEA recommended a design modification for these air intake boxes, including spare parts, to eliminate the risk of paint delamination.