11. Rigid airships became the first aircraft to transport passengers and cargo over great distances.12. Rigid airship design and advancement was pioneered by the German count Ferdinand von Zeppelin.13. A : The LZ-127 Graf Zeppelin is considered the most successful rigid airship ever built. 14. The airport was named after the noted American Navy rigid airship pioneer, Lt . Cmdr. 15. The first American-built rigid airship , the, flew in 1923. 16. A non-rigid airship relies entirely on internal gas pressure to retain its shape during flight. 17. Unlike semi-rigid and rigid airships ( e . g. 18. France's only rigid airship was designed by Chenu 200 hp engine that drove two propellers. 19. O'Conner transfers to the US Naval Air Service and is assigned to the rigid airship . 20. The British Royal Navy took an early interest in rigid airships and ordered Wolseley engines.
