Goodyear upgrades from blimps to Zeppelins

The Goodyear Tire & Rubber Co., Akron, Ohio, will begin replacing its fleet of blimps with Zeppelin LZ N07-101s beginning in 2013 as the blimps begin to age out. Zeppelins will then make up the firm’s entire U. S. airship fleet by about 2017. (Goodyear also has a blimp based in China.) According to the company, the new airships, which can be called Zeppelins or dirigibles, will fly faster, carry more passengers, and be equipped with state-of-the-art avionics and flight controls. Each of the three dirigibles, along with tech support, will cost about $21 million.

Trading up

The new Zeppelins will be semirigid airships, meaning a 1.2-ton aluminum and carbon-fiber framework will support the outer skin, engines, gondola (the passenger and crew compartment), and the three airfoils that form the inverted “Y” pattern that make up the tail structure. The outer envelope or skin contains the lifting gas, helium. There are no individual cells or a separate inner envelope. The skin is a laminate of polyester fabric and Tedlar, a film from DuPont, with a polyurethane coating.

One advantage of semirigid airships is that if the envelope catastrophically ruptures and helium floods out, the structure will hold the airfoils in place — maintaining some flight control — and preventing the envelope from collapsing over the gondola, which would effectively blind the pilot. Current blimps, built by Goodyear and Lockheed Martin, have no internal structure — they’re really just inflated bags made of polyester fabric coated with neoprene rubber.

For power, the Zeppelins will rely on three 200-hp Textron Lycoming IO-360 piston engines. Two are mounted in nacelles on each side of the airship, about a third of the way back from the nose. Both side engines employ variable-pitch “puller” props that can mechanically swivel from up 0 to 120°. So between the variable-pitch prop, which lets the prop push or pull in varying amounts, and the swivel action, the pilot has thrust control over the airship’s pitch and roll. The third engine is on the rear of the airship, behind the tail. Its prop, usually acting as a pusher, swivels up from 0 to 90°. The rear engine also carries a secondary prop pointed sideways and dedicated to yaw control. The lateral prop gives a hovering Zeppelin the ability to do a zero-radius or pivot turn.