108 fatalities

1973-04-10: Vickers Vanguard (G-AXOP) — Invicta International Airways — Hochwald, Switzerland

Hochwald, SwitzerlandLanding (descent or approach)

On April 10, 1973, a Vickers Vanguard (registration G-AXOP) operated by Invicta International Airways was involved in an aviation accident near Hochwald, Switzerland during landing or approach. 108 people were killed. Investigators recorded the probable cause as: The crew experienced a loss of situational awareness during ILS approaches due to inadequate navigation, confusion of aids, and insufficient instrument cross-checking. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 1 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781232841Data APIEditorial standards
Aircraft registered G-AXOP
Aircraft registered G-AXOP. Photo: Richard Vandervord / CC BY-SA 4.0, via Wikimedia Commons

A charter flight operated by Invicta International Airlines crashed into a wooded hillside during an approach to Basel-Mulhouse, resulting in 108 fatalities.

What happened

A Vickers Vanguard operated by Invicta International Airlines was performing a charter service from Bristol to Basel-Mulhouse when the aircraft impacted terrain approximately 15 km southeast of the airport. During the approach, weather conditions were characterized by low cloud bases and limited visibility. The flight crew was navigating via various radio beacons, including the BN and MN NDBs, with instructions to descend and execute specific turns for the final approach to runway 16.

As the aircraft progressed through its arrival sequence, the crew's reported positions became increasingly inconsistent with their actual location. While reporting they were over specific navigational aids, the aircraft was actually flying significantly south of the airfield and off the extended centerline. The captain eventually noted potential issues with spurious indications and difficulty with the ADF due to weather conditions. During the final stages of the descent, the pilot reported being at 1,400 feet, at which point air traffic control suggested the aircraft might be positioned south of the airport. Shortly after, the aircraft struck a wooded area of hills. The impact caused the plane to disintegrate, leaving only the tail section intact. Of the occupants on board, 108 fatalities occurred, while 37 individuals, including two flight attendants and 35 passengers, survived.

Findings

The accident was driven by a loss of orientation during two separate ILS approaches conducted under instrument flight conditions. Several contributing factors were identified, including imprecise initiation of the final approach regarding both altitude and the approach centerline, as well as general confusion regarding navigational aids. The crew failed to perform sufficient cross-checks of instrument readings and navigation equipment. Furthermore, technical difficulties, such as poor reception of medium wave beacons and malfunctions in the localizer and glide slope receivers, significantly hindered the crew's ability to navigate accurately.

Probable cause

The crew experienced a loss of situational awareness during ILS approaches due to inadequate navigation, confusion of aids, and insufficient instrument cross-checking.