Invicta International Airlines Flight 435 crashes in a snowstorm on approach to Basel, Switzerland, killing 108 people.

Invicta International Airlines Flight 435 (IM435) was a Vickers Vanguard 952, flying from Bristol Lulsgate to Basel-Mulhouse, which crashed into a forested hillside near Hochwald, Switzerland on 10 April 1973. The aircraft somersaulted and broke up, killing 108 people, with 37 survivors. To date, this is the deadliest accident involving a Vickers Vanguard and the deadliest aviation accident to occur on Swiss soil. Many of the 139 passengers on the charter flight were women, members of the Axbridge Ladies Guild, from the Somerset towns and villages of Axbridge, Cheddar, Winscombe and Congresbury. The accident left 55 children motherless and became known in the British media as the Basle air crash.

Basel, also known as Basle, is a city in northwestern Switzerland on the river Rhine. Basel is Switzerland's third-most-populous city, with 177,595 inhabitants within the city municipality limits.