Wallis' first concept was for a ten-ton bomb that would explode some 130 feet (40 m) underground. To achieve this, the bomb would have had to be dropped from 40,000 feet (12 km). The RAF had no aircraft at the time capable of carrying a ten-ton bomb load aloft, let alone lifting it to such a height. Wallis designed a six-engine aeroplane for the task, called the "Victory Bomber", but he was not taken seriously by the military hierarchy of the day.