Mark Keitel wrangled the Goodyear Blimp at AirVenture 2008. Its neural buoyancy makes such feats possible. Photo by Frederick A. Johnsen

When the Goodyear blimp Spirit of Goodyear returned to AirVenture 2008, its support crew included multi-tasking Mark Keitel. Mark’s business card reads Senior Radio and TV Technician, Aircraft Mechanic. He’s also a commercial big-rig driver, which comes in handy when the ground crew paces the blimp to outlying locations from its home base in Akron, Ohio.

Mark can fix the blimp, support it, and operate hi-definition video cameras from the sky for coverage of major sporting events. His blimp, built as Goodyear’s America in 1984, was rechristened when it was refurbished in 2000. Goodyear keeps three blimps in the air over the United States, and it has a refurbishing program in place to ensure blimps continue flying indefinitely. The rubberized envelope that gives the blimp its characteristic shape can still be built by a Goodyear contractor in Ohio, Mark said.

Spirit of Goodyear and its sister ships are model GZ-20A, with synthetic fabric envelopes. They are similar to the smallest blimps Goodyear made for the U.S. Navy decades ago, Mark explained. Two Continental IO-360 engines push the blimp at a leisurely cruising speed of about 35 mph, with a top speed at 50, he said. If the wind is blowing around 20 or 30 mph, Mark said the pilot may choose to remain moored on the ground. It’s tough to make headway when the wind matches the blimp’s forward speed.

When the Goodyear company decided to paint lower surfaces dark blue on the blimp, it bulked up by 400 pounds. In a light rain, the blimp’s hide can retain 600 pounds of clinging water. Such weight penalties cannot be ignored, so the Spirit of Goodyear now has an illuminated LED billboard only on its left flank, capable of flashing messages in flight at night.

Mark said the blimp is ballasted to neutral buoyancy; while he spoke about it, the blimp behind him occasionally rose a few feet off the grass, returning gently to bounce on its single balloon tire. Air moving over the huge teardrop-shaped envelope creates some lift.

The football-shaped blimp exterior envelope conceals two ballonets—air bladders—inside its shape. By shifting air pressure in the forward and aft ballonets, the blimp can be trimmed nose up or down. Since the blimp has no rigid structure, when it descends from altitude the outside atmospheric pressure increases, causing the helium to contract. The ballonets automatically take in more air to inflate sufficiently to keep the blimp’s envelope taut.

The gondola beneath the envelope is where the pilot and up to six passengers can ride. It actually hangs from support cables leading to a saddle, or catenary curtain, cemented to the inside of the top of the envelope.

With a history in blimp-making reaching back to 1925, Goodyear built the first blimp that flew over the Olympic Games, at Los Angeles, in 1932. Goodyear was the first to cover a sporting event with a television camera aboard a blimp in 1960 for the Orange Bowl. Now, the company’s blimps cover about 100 televised events a year.

While at AirVenture 2008, the Goodyear blimp is scheduled to fly over Wittman Field on Thursday and Friday between about 2:30 and 6:30 p.m.