Diamond DA40 accident at La Grand'Combe aerodrome (F-GUVK)

Flight details and accident sequence On 10 June 2015, a Diamond DA40 registered F-GUVK, operated by a club, departed runway 15 at Salon Eyguières aerodrome at approximately 13:00 local time. The pilot, based at Salon Eyguières, flew to Uzès aerodrome and landed on runway 18. Unable to find a parking area, the pilot decided to continue to La Grand'Combe aerodrome. At La Grand'Combe, the pilot performed an aerodrome reconnaissance and initiated an approach to runway 17. During the final approach, the pilot was unable to reduce speed sufficiently and executed a go-around. After another reconnaissance pass to check wind conditions, the pilot approached runway 35. During landing on runway 35, the aircraft overran the runway longitudinally and came to rest below the runway. The aircraft was destroyed. ## Aerodrome and meteorological conditions La Grand'Combe aerodrome is located on a hilltop and surrounded by terrain. It is reserved for based aircraft and those based at neighboring aerodromes; pilots holding mountain qualifications may also land there. The aerodrome has an unpaved runway measuring 780 meters by 60 meters. The VAC chart notes turbulence risk on final when wind exceeds 20 kt and significant downdrafts near threshold 35 in easterly winds. Runway 35 is preferred due to significant downdrafts in northerly winds. Estimated meteorological conditions at the accident site were: wind from 175° at 5 kt; visibility greater than 10 km; cloudy sky with cumulus and stratocumulus with bases around 1,000 meters; temperature 25°C. A thunderstorm cell was approaching from the south. ## Pilot information and testimony The pilot had 166 total flight hours, including 10 hours on type and 3 hours in the preceding three months, all on type. The last three hours were flown with an instructor after more than five months without flying. The pilot reported some difficulty handling the DA40, which he considered very “pointy.” The pilot had previously landed at La Grand'Combe five years earlier in a Robin DR400. Before departure, the pilot had consulted weather forecasts and noted calm winds with a southerly flow. With conditions expected to deteriorate after 17:00, the pilot planned to return before 15:30. The pilot had calculated a landing distance of 700 meters. During the first reconnaissance, the pilot observed crosswind with a slight southerly component. During the second reconnaissance, the pilot observed crosswind with a northerly component of approximately 15 kt. Having had difficulty reducing speed on the first approach, the pilot thought the wind direction may have changed. On the second approach, the pilot stated that he failed to reduce speed to 65 kt; the speed was 70 kt, but he continued the approach because the aircraft was on the glide path. When extending the second flap setting, the aircraft passed slightly above the glide path. The pilot did not recheck speed. According to the pilot, the aircraft touched down after the first third of the runway and shortly afterward bounced over a bump while banking. The pilot leveled the wings and landed again. Judging braking ineffective, the pilot attempted to skid to the right without effect. ## Aircraft performance and club procedures The recommended approach speed was 63 kt at the day's weight. According to the flight manual, the landing distance at the day's weight and temperature was 675 meters on a paved runway in no wind, and the landing roll distance was 260 meters. No provision was made for a tailwind component. For an unpaved runway, a correction of 5% to 25% depending on grass height must be added to the landing roll distance. For comparison, the landing distances of the aircraft the pilot had previously used at La Grand'Combe were: at maximum weight and the day's temperature, a landing distance of 675 meters and a landing roll distance of 320 meters on an unpaved runway. The club president stated that the pilot had not informed him of the intention to land at La Grand'Combe. Given the pilot's limited recent experience and the day's conditions, the president would have encouraged choosing another destination. The club has a procedure for releasing pilots on aerodromes it considers complex, including La Grand'Combe, particularly due to runway length, specific aerology, and the unpaved runway. Users must perform two touch-and-goes on each QFU with an instructor.