Aero Linx: Dirigibles, Zeppelins, and Blimps: The Differences Explained A dirigible is any lighter-than-air craft that is both powered and steerable (as opposed to free floating, like a balloon). Blimps like the Goodyear blimp, rigid airships like the Hindenburg, and semi-rigid airships like the Zeppelin NT are all dirigibles. The word “dirigible” is often associated with large rigid airships, but the term does not come from the word “rigid” but rather the French verb diriger (“to steer”).

Permanent Echo Radar signals reflected from fixed objects on the earth's surface; e.g., buildings, towers, terrain. Permanent echoes are distinguished from "ground clutter" by being definable locations rather than large areas. Under certain conditions they may be used to check radar alignment.

"The Cargolux Board of Directors approved the order of our 14th 747-8 Freighter almost 35 years to the day that the airline took delivery of its first 747 Freighter ever. This shows how pleased we, as an all-747 cargo operator, are with the performance and economics of this new generation aircraft and underlines the importance of the role of the 747 overall in the success of our company." Source: Richard Forson, interim president and CEO of Cargolux, following the announcement of a Cargolux Airlines order for an additional 747-8 Freighter from Boeing. The order, valued at $357.5 million at list prices, is the 14th 747-8 Freighter the Luxembourg-based cargo carrier has ordered from Boeing.