Fallo estructural del EoN Olympia 460 durante lanzamiento por cabrestante en el aeródromo de Sleighford

El 13 de julio de 1996, un EoN Olympia 460 experimentó un fallo estructural fatal durante un lanzamiento por cabrestante en el aeródromo de Sleighford, Staffordshire. El planeador, pilotado por una persona con aproximadamente 50 horas de experiencia de vuelo, sufrió una falla catastrófica del ala poco después del despegue. Testigos observaron oscilaciones de cabeceo inusuales y flexión de las alas antes de que fallara el ala derecha. La aeronave fue destruida y el piloto no sobrevivió. Investigaciones posteriores revelaron una corrosión significativa en el larguero del ala, lo que llevó al fallo.

1. Winch launch climb: The glider began a winch launch from Sleighford Airfield, quickly becoming airborne and adopting the climb attitude in what witnesses considered a faster, less steep than normal launch.
2. Degraded wing spar: Long-term corrosion and bond failure in the right wing spar root alloy strap assemblies had significantly reduced the structural strength of the spar.
3. Over-strong weak link: The winch cable weak link assembly, using two identical 500 kg links in parallel, was found to fail at about 987 kg, allowing excessive launch loads to be transmitted to the airframe.
4. Excessive launch loading: During the winch climb at around 600–700 feet, the combination of a fast launch and over-strong weak link likely imposed loads that exceeded the degraded right wing spar’s strength.
5. Pitch oscillations and flex: While still on the cable in a nose-high attitude, the glider developed relatively rapid pitch oscillations and witnesses observed abnormal wing flexing.
6. Right wing structural failure: As the airbrakes briefly deployed and then deployed again, the right wing main spar failed, the wing pivoted upwards and rearwards with debris released, and the cable separated from the glider.
7. Crash - fatal: With the right wing failed at low altitude, the glider broke up and impacted the ground before the pilot could escape by parachute, fatally injuring the pilot and destroying the aircraft.