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A hybrid airship is an aircraft that combines characteristics of lighter-than-air (LTA), airship technology with heavier-than-air (HTA) technology, either fixed-wing or rotary-wing. A ''rotastat'' is a rotorcraft/airship hybrid typically intended for heavy lift applications, while a ''dynastat'' is a dynamic lift airship typically intended for long-range cruising. No production designs have been built, but several manned and unmanned prototypes have flown. The term "hybrid airship" has also been used to describe an airship combining elements of different types of airships. ==Characteristics== Conventional airships have low operating costs because they need no engine power to remain airborne, but are limited in several ways, including low payload/volume ratios and low speeds. Additionally, ground handling of an airship can be difficult. Because it is floating, in even a light breeze it is susceptible to wind buffeting. On the other hand, heavier-than-air (HTA) aircraft, especially rotorcraft, require the constant use of power to generate lift, and conventional airplanes also require runways. The hybrid airship combines the airship's aerostatic lift, from a lighter-than-air gas such as helium, with the heavier-than-air craft's dynamic lift from movement through the air. Such a hybrid craft is still heavier than air, which makes it similar in some ways to a conventional aircraft. The dynamic lift may be provided by helicopter-like rotary wings (the ''rotastat''), or a lift-producing shape similar to a lifting body combined with horizontal thrust (the ''dynastat''), or a combination of the two.〔Khouty (2012).〕 Hybrid airships are intended to fill the middle ground between the low operating cost and low speeds of traditional airships and the higher speed but higher fuel consumption of heavier-than-air craft. By combining dynamic and buoyant lift, hybrids are intended to provide improved airspeed, air-cargo payload capacity and (in some types) hovering capability compared to a pure airship, while having longer endurance and greater lifting capacity compared to a pure HTA type. Hybrid aircraft technology is claimed to allow a wider range of flight-performance optimizations ranging from significantly heavier than air to near buoyant. This perception of uncommon dynamic flight range when coupled with an appropriate landing system is claimed to allow ultra heavy and affordable airlift transportation. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「hybrid airship」の詳細全文を読む スポンサード リンク
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