ASW 20 F crashes after elevator ball joint disconnects on takeoff

A Centrair ASW 20 F crashed at Bailleau-Armenonville during a national competition; the pilot was seriously injured. The glider had been re-rigged that morning with help from a person unfamiliar with the type; the elevator L'Hotellier ball joint was most likely connected without its safety pin. After takeoff the glider bounced repeatedly, pitched up >30° at end of runway, and climbed to ~35 m; the pilot released and the glider nose-dived ~70 m from threshold 18. BEA cited a disconnected elevator ball joint that explained the loss of pitch control, with abnormal joint wear remaining an alternative.

1. Aerotow takeoff at competition: Centrair ASW 20 F (F-CFFF, built 1979, ~2,300 h total). Pilot 25 yo, SPL since 2017 with aerotow + winch ratings, ~1,000 h total; owner of the glider since 2021 and aware of risks of misrigging the elevator on this type. The pilot was competing in the French national glider championships at Bailleau-Armenonville (Eure-et-Loir, 27 May – 3 June 2023). Aerotow takeoff at ~13:05 local from RWY 36 (unpaved, 780×100 m). Weather: NE wind 9 kt, 22 °C, CAVOK.
2. Re-rigged morning of accident: The pilot had outlanded the previous day (2 June) and derigged the glider. On the accident morning (3 June) the glider was re-rigged with help from another person.
3. Helper unfamiliar with the type: The person assisting with re-rigging did not know this glider type. The pilot stated he showed the helper 'in detail' how to assemble the glider. The pilot was particularly aware of the rigging risk — the competition organisers had reminded pilots three times (briefing, WhatsApp, on the field before takeoff) to check the flight-control assembly, and this was the only competing glider with manual elevator connection rather than automatic.
4. L'Hotellier joint, no safety pin: The ASW 20 F elevator uses an L'Hotellier ball joint with a manual locking pin (verrou). A safety pin (goupille) can be inserted to prevent accidental disengagement. The pilot stated he never used the safety pin; the manufacturer does not impose it, but the LBA (1993), FAA, Netherlands, Norway and Australia have made it mandatory. The pilot's rigging check was visual only (looked for the hole in the locking pin) — BEA showed this is insufficient: the ball can be partially engaged with the hole still visible.
5. Abnormal joint wear beyond tolerances: BEA examination: the ball had a flat spot (méplat) at its contact surface with the seat; the sphericity variation was about 0.3 mm — three times the 0.1 mm threshold given by the L'Hotellier maintenance instructions (IMA 10.01). The wear was not detected at the most recent annual inspection. The ball/socket had been installed for >30 years, well beyond the 10-year / 3,000-launch replacement criterion introduced by L'Hotellier in 2009 — but this updated criterion was never communicated to ASW 20 F operators (it was added to Pégase manuals but not ASW 20 F).
6. Elevator joint disconnected at takeoff: During the takeoff roll the glider bounced repeatedly and touched down hard. At end of runway it pitched up suddenly to >30° nose-high; the pilot tried to push forward but the elevator 'no longer responded'. The glider climbed to ~35 m, ~20 m above the tug. BEA scenario: the joint was very likely incompletely connected at rigging (insertion possible without lock); however, abnormal joint wear plus the takeoff rebounds may also have caused an in-flight disconnection — neither could be excluded.
7. Tow release at ~35 m: At ~35 m height the pilot released the aerotow cable. Witnesses then saw the glider descend and observed the flaps deploy. The pilot stated he deployed flaps in negative to 'give a moment of pitch-up' and reduce the ground impact, then moved them to positive just before impact.
8. Uncontrolled nose-down, crash, destroyed: Glider impacted the ground violently, coming to rest ~70 m from threshold 18. Cockpit damaged from ground impact; elevator-control ball joint found disconnected between the vertical control rod and the elevator; airbrakes extended; flaps in positive but exact position not determined. Pilot seriously injured. Tug pilot landed without incident. BEA safety recommendations include: AESA make safety pin mandatory on flight-control L'Hotellier joints (FRAN-2025-002); ensure proper distribution of L'Hotellier maintenance updates to type-certificate holders (FRAN-2025-003, -004). Post-accident the FFVP issued a safety bulletin requiring safety pins; Centrair amended the ASW 20 F flight manual to make the safety pin mandatory.