What happened
On August 31, 2009, a Robin DR 400-120, registration F-GNNI, was performing a training flight from the Toulouse Lasbordes aerodrome. During the initial climb, after reaching an altitude of approximately 200 feet, the student pilot reported a significant reduction in engine power.
Upon noticing the power loss, the instructor took control of the aircraft. As the engine RPM stabilized at approximately 1,200 RPM, the instructor determined that an emergency landing in a nearby field was necessary. The crew declared an engine failure, activated the emergency beacon, and deployed the flaps in the landing position. The aircraft successfully landed in a field and came to a stop after rolling for 130 meters. There were no injuries and no damage to the aircraft.
The investigation
The investigation focused on the cause of the engine power loss. Upon disassembly of the carburetor, investigators discovered that the passage leading to the main jet was obstructed by an insect.
Evidence suggested that the insect likely entered the carburetor through the carburetor heat intake. This was made possible because the aircraft had been parked with the carburetor heat control in the "hot" position. The crew members did not recall moving the control to the normal position during their pre-flight checks, and the instructor noted that he had previously encountered the control left in the "hot" position during other pre-flight inspections.