§ Mr. Thorneycroft
The aircraft will exceed the speed of sound at low level and the ground effect will be considerable. This performance will be used only over hostile territory or over deserted areas and the sea.189W
In normal low level flight over sparsely inhabited regions the aircraft will fly at slightly below the speed of sound. The aircraft will then be using only a part of the very great power of its engines and the noise on the ground will be less than that of other aircraft which achieve this performance only under full power. At this speed the aircraft will not cause damage to property or animals.