History of the Flight
The pilot, accompanied by four passengers, took off at 16:39 from paved runway 04 at Grenoble Le Versoud aerodrome for the second sightseeing flight of the afternoon. The pilot climbed on the axis and then turned right into the Les Adrets valley, flying alongside the northern slope of the mountain to the south of Les Adrets. Witnesses reported seeing the airplane heading east at low height and flying slowly. A few minutes later, the airplane flew through a line of trees and crashed into a field, where a post-impact fire broke out.
Wreckage and Site Examination
The wreckage was found in the commune of Les Adrets, about 11 km from Grenoble-Le Versoud aerodrome, at an altitude of 860 m in a meadow surrounded by trees 20 to 25 m high. The accident site is located 0.4 NM from the last recorded flight point, along a path of approximately 100°. The wings were torn off, and the forward section of the fuselage struck the ground, causing the airplane to invert. A fire destroyed most of the wreckage. Several branches were severed by the propeller, indicating that the engine was delivering power at impact, though the amount could not be determined. The flight control linkages were continuous. The positions of the flaps and elevator trim could not be determined. The propulsion system and associated circuits were largely destroyed, but internal examination of the engine and equipment revealed no anomalies.
Pilot Information
The 66-year-old pilot held a Private Pilot Licence (PPL(A)) obtained in 2016, with 400 flight hours total, 92 of which in the last 12 months. He had conducted 92 sightseeing flights in the last 12 months for the flying club, half on D140s and half on DR400 and DR401/155 aircraft.
Meteorological Conditions
Data from the Grenoble-Le Versoud weather station between 16:00 and 17:00 indicated northerly wind of 3 kt, CAVOK, temperature of 32°C, and QNH 1017 hPa. Météo-France estimated for the accident area north-easterly wind of 5 kt, clear to slightly cloudy with no low cloud, warm dry air mass with humidity around 40%, and no icing risk.
Aircraft Information
F-HJLB was a Jodel D140 C low-wing monoplane made of wood and canvas, with conventional landing gear, powered by a Lycoming O-360-A3A engine (180 hp) and a two-blade fixed-pitch metal propeller. It was equipped with skis. The aircraft had been returned to service on 19 May 2022 after carburettor replacement, and five subsequent flights showed no power anomalies. At start-up, estimated weight was 1,131 kg (maximum take-off weight 1,200 kg), with balance slightly aft. At the time of the accident, weight was estimated at 1,125 kg. The flight manual indicates an optimum climb speed of 150 km/h and a stall speed (flaps retracted) of 92 km/h.
Performance Analysis
Using the flight manual chart under prevailing conditions (ISA +18°C, altitude 2,800 ft, weight 1,125 kg), the theoretical climb performance without skis was approximately 530 ft/min. Experienced pilots estimate a 20% reduction with skis, yielding about 430 ft/min. During the initial climb, ground speed was around 65 kt, decreasing to 57 kt at the last recorded point. The observed climb slope on the second part of the flight was 5.3%, corresponding to about 350 ft/min at 120 km/h. Height above terrain at the last point was about 250 ft and decreasing. The average terrain slope after that point was 9.6%, not accounting for the line of trees. To maintain constant height above terrain, a climb speed of approximately 780 ft/min at 150 km/h would have been required, nearly double what was observed.