be capable of carrying a much greater payload; there was a view that the existing craft was uneconomic for what payload it could carry and that an expanded, or 'stretched', model would be able to rectify this. According to Saunders-Roe's own projections, an increase of the craft's payload by 110 per cent would only reduce performance by 10 per cent as the increased payload was in part offset by the expanded cushion area, which meant that cushion pressure would not need to be substantially increased instead.

The first craft to be lengthened