The elevators were aerodynamically balanced but the rudders were unbalanced. When the designers learned that R101 had been fitted with servo motors at a substantial cost in weight and money they thought that they had made a mistake and rechecked their calculations. They eventually concluded that their calculations had been correct: when R100 was flown the controls proved both light and effective, and its control characteristics were compared favourably with those of R101 by Nöel Atherstone, First Officer of R101. R100 was built suspended from the roof of its shed. The individual transverse frames were assembled horizontally then lifted up and slung from roof-mounted trackways before being slid into position and attached to the adjacent frames by the longitudinal girders. The ship remained suspended until the gasbags were inflated with hydrogen.