No fatalities

Heavy Landing During Experimental Flight at Jan Smuts Airport (G-AOYF)

Johannesburg-Oliver Reginald Tambo (Jan Smuts), South AfricaLanding (descent or approach)

On October 20, 1957, a Vickers Viscount (registration G-AOYF) operated by Vickers-Armstrongs Ltd was involved in an aviation accident near Johannesburg-Oliver Reginald Tambo (Jan Smuts), South Africa during landing or approach. No fatalities were reported. Investigators recorded the probable cause as: The misjudged roundout resulted in a heavy landing which caused the starboard undercarriage to collapse. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 6 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 2026-06-12Data APIEditorial standards

During an experimental flight at Jan Smuts Airport, a heavy landing caused the starboard undercarriage to collapse. The aircraft sustained substantial damage but no injuries occurred.

Incident Overview

An experimental flight was conducted at Jan Smuts Airport, where the aircraft was temporarily based for manufacturers' tests. The flight was operated under the special categories of Research or Experimental and Demonstration. The purpose was to gather data for inclusion in the Aircraft Flight Manual for certification for public transport operations.

Flight Sequence

The captain was cleared to use runway 03, the main instrument runway, and took off at 1040 hours. After completing a circuit, the captain was cleared to land back on runway 03. During the approach, the aircraft held at an altitude of 300 to 400 feet until passing over the threshold.

Landing and Aftermath

Upon crossing the threshold, the angle of descent increased to approximately 45°. The descent continued until the aircraft was about 70 feet above the runway surface, where it leveled out. However, the path of descent remained fixed at about 45° until touchdown. At touchdown, the main landing gear bogies appeared to move rearwards and inwards, with the starboard side moving further rearwards than the port side. The aircraft then bounced a few feet before settling further down the runway. Heavy smoke was emitted from both bogies as the aircraft continued forward. It eventually swung to the right and off the runway, coming to rest on a heading of 180° magnetic at a point approximately 1,590 yards from the threshold. No one was killed or injured, but the aircraft was substantially damaged.

Probable Cause

The misjudged roundout resulted in a heavy landing which caused the starboard undercarriage to collapse.