History
On 8 April 2019, a Robin DR400-180 registered F-GEKG was conducting a dual night training flight from Nîmes Garons airport to Montpellier Méditerranée and back. After returning, the pilot in training performed a touch-and-go on runway 18. During the second circuit, while configuring the aircraft for approach, the instructor pulled the carburetor heat control. At the end of the downwind leg, as the pilot turned onto base leg, engine speed suddenly decreased. The instructor applied power and engine speed rose to 1,600 rpm. As the aircraft was under the approach path with excessive speed, the instructor asked the pilot to level off and reduce power. When power was reduced, engine speed dropped abnormally and the engine stopped. The instructor took control, aimed for the runway approach lights, attempted an engine restart without success, and performed a forced landing short of the runway.
Aircraft Information
F-GEKG is equipped with a Lycoming O-360 A3A piston engine. The carburetor system includes a mixing chamber for selecting hot air (carburetor heat) to prevent or clear icing. The aircraft does not have a carburetor temperature indicator. According to the flight manual, carburetor heat should be operated on an on-off basis; an intermediate position may worsen icing.
Pilot Experience
The pilot held a PPL(A) since January 2019, with 68 flight hours (12 as pilot-in-command) and 3 hours on type. The instructor held a CPL(A) with night and instructor ratings since 2012, logging 1,568 hours (52 at night).
Meteorological Information
Weather at 22:00 at Nîmes Garons: wind 25004 KT, CAVOK, temperature 11°C, dew point 8°C. Météo-France estimated at the accident site: at 800 ft, air temperature +13.1°C, dew point -1.8°C; near ground, +11°C and +7°C. A thin maritime advection and night-time cooling created a temperature inversion trapping moisture. After evacuation, pilots noted heavy dew on the aircraft and wet grass.
Wreckage and Site
The aircraft came to rest within the obstacle free zone of the runway approach lights, about 75 m after the touchdown point and 865 m before the threshold of runway 18. Three approach light posts were torn off by the left wing, one by the right wing. Examination of the aircraft and fuel system revealed fuel in the tanks. No anomalies were found that could explain the engine shutdown; the engine restarted normally days later.
Probable Cause
Carburetor icing that likely began during the downwind leg due to lack of preventive use of carburetor heat, resulting in engine shutdown.