Jodel D140C accident at Banon altisurface (F-BMFT)

Flight and Accident Sequence On 1 July 2015, a Jodel D140C registered F-BMFT, operated by a club, departed from Grenoble Le Versoud aerodrome with a pilot and one passenger on board. The aircraft made successive landings at the Superdévoluy and Clamensane altisurfaces before proceeding to the Banon altisurface in the Alpes-de-Haute-Provence department. At Banon, the pilot conducted two circuit reconnaissance passes over the landing area. During the final approach to runway 35, the aircraft was close to the ground and approximately 200 meters from the threshold when the pilot interrupted the landing and applied full power. The aircraft gained altitude but struck trees at the end of the runway, entered a left turn, and subsequently struck additional trees and the ground. ## Wreckage and Meteorological Conditions Examination of the wreckage showed that the aircraft impacted the ground in a nose-down attitude with a strong left bank. The engine was producing power, with the throttle found advanced, the mixture control leaned out, the carburetor heat control advanced, the electric pump on, and the fuel selector set to the rear tank. The flaps were extended. Estimated meteorological conditions at the accident site included a south-easterly wind of 5 to 15 knots, CAVOK, and a temperature of 23 °C. Upper-level winds were from the west to north-west, while surface and low-level winds were light to moderate from the south-east. The air mass was unstable, with thermal updrafts present. The passenger reported calm winds during the reconnaissance, while the altisurface owner stated that the wind was from the east at 20 to 30 km/h. ## Site and Aircraft Data The Banon altisurface has two perpendicular runways, with runway 17/35 being the preferred runway and 500 meters long. Runway 17 was used for takeoffs and runway 35 for landings. The landing runway had an 11% slope over its first half and was slightly descending over the second half. The final approach was to the east of a north-south oriented ridge. The aircraft was equipped with an ISEI Safety Plane data recorder, which provided real-time data. The recorded data established the flight path, confirmed that engine parameters were nominal, and determined airspeed and groundspeed. During the final approach, groundspeed increased and the pilot significantly reduced power. ## Personnel The pilot held a private pilot license (PPL(A)) and a mountain qualification, with a total of 987 flight hours, including 16 hours in the preceding three months, of which 14 were on type. The passenger, who was the club president, held a PPL(A) but did not have a mountain qualification. ## Findings The investigation concluded that the pilot's reconnaissance did not allow for a correct wind estimate or identification of all elements necessary for a stabilized final approach. Data analysis confirmed that the approach was unstabilized, with increasing groundspeed during the final approach, likely due to a tailwind component or updrafts caused by the terrain. The accident was attributed to the pilot's decision not to interrupt the approach before entering the descent.