Hybrid airship

A hybrid airship is a powered aircraft that obtains some of its lift as a lighter-than-air (LTA) airship and some from aerodynamic lift as a heavier-than-air aerodyne.

A dynastat is a hybrid airship with fixed wings and/or a lifting body and is typically intended for long-endurance flights. It requires forward flight to create the aerodynamic lift component.

A rotastat is a hybrid airship with rotary wings and is typically intended for heavy lift applications. Its rotary wings can provide lift even when hovering or manoeuvring vertically, like a helicopter.

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 comprising a mix of rigid, semi-rigid, and non-rigid construction.

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.

...
Wikipedia