Bombing from high altitudes posed several issues, principally amongst these being accuracy. Wallis himself acknowledged that the accuracy called for to employ the penetration bomb from 40,000 ft was difficult to achieve; specifically, there was an assumption that around 25 per cent of days throughout the year would be suitable for performing bombing missions in, but that during such missions the benefits of being undisturbed from ground-based anti-aircraft fire would lead to equivalent accuracy to conventional bombers flying at 15,000–20,000 ft under gunfire. In response to these difficulties, Wallis had proposed the adoption of a new gyroscopic bombsight to provide for greater accuracy. The Victory Bomber was to have been capable of traversing substantial ranges, being able to launch bombing missions upon Moscow in Russia from airfields around London in the United Kingdom; Wallis also promoted the aircraft as being the potential basis for post-war civil aircraft capable of performing direct transatlantic crossings.