Airship

A technologically advanced cousin of the balloon, airships are streamlined vessels buoyed by gases and controlled by means of propellers, rudders, and pressurized air systems. More commonly referred to as blimps and dirigibles, the airship is comprised of non-rigid, semi-rigid, and rigid types that rely on lighter-than-air gases such as helium and hydrogen for lift. Since the turn of the twentieth century, they have been engaged commercially in the transport of passengers and cargo and have proven a successful means of advertising.

Airships derive their lift from forward motion, just as an airplane does, and all three types have long used the internal combustion engine, like the type used in automobiles, to propel their massive bodies through the air. These have included the earliest motorcycle engines, the diesel engines of the mammoth American ships Akron and Macon, and the beefed-up Porsche engines used to power a new generation of airships. Traditional pressure airships house the engine, propeller, and gear box on an outrigger that extends from the side of the car, while the modern British Skyship's 500 and 600 use inboard engines that turn long prop shafts which allow the propellers to be vectored outboard. The introduction of pivoted, or vectored, engines gave airships the ability to change the direction of thrust and afforded it such amenities as near-vertical lift-off, thus reducing the need for long runways. Capable of airborne refueling, airships can remain aloft for weeks at a time, reaching an average airspeed of 60 MPH (96.5 km/h).