A Viscount 806, temporarily based in Johannesburg, conducted test flights involving measured takeoffs and landings. During a circuit, the captain cleared to land back on runway 03. The aircraft passed the threshold at 400 feet and the descent angle increased to 45 degrees, leveling off at 70 feet above the runway. Upon touchdown, the main bogies appeared to move rearwards, causing the aircraft to bounce and land back to the runway. The aircraft swung off the runway and came to rest 1590 feet past the threshold, with heavy smoke emanating from the main gear. The fuselage was used to construct Vickers 806 Viscount c/n 418.A Viscount 806, temporarily based in Johannesburg, conducted test flights involving measured takeoffs and landings. During a circuit, the captain cleared to land back on runway 03. The aircraft passed the threshold at 400 feet and the descent angle increased to 45 degrees, leveling off at 70 feet above the runway. Upon touchdown, the main bogies appeared to move rearwards, causing the aircraft to bounce and land back to the runway. The aircraft swung off the runway and came to rest 1590 feet past the threshold, with heavy smoke emanating from the main gear. The fuselage was used to construct Vickers 806 Viscount c/n 418.