The Takeoff and the Landing
Though blimps are considered lighter-than-air aircraft, pilots can control their buoyancy and adjust their weight during a flight. During takeoff, some blimps are adjusted to “fly heavy,” meaning they are not weightless, but rather the volume of helium is adjusted so the blimp settles naturally to the ground. For example, if a Goodyear blimp settled down on a bathroom scale in its takeoff configuration, it would weigh about 150 pounds. Because it weighs that much, it must actually take off almost like an airplane, though from a much shorter runway, making a short forward run before the pilot uses the elevator controls to pitch the nose upward so the thrust from the propellers gives the blimp an upward push.
Here’s how a blimp gets off the ground. A ground crew, which can number as many as 15 people, grasps a railing near the base of the gondola. In unison, they press down hard on the rail, pushing the blimp down on its springy landing gear tire. The bouncy rebound, caused by springlike assemblies inside the gear mechanism, sends the blimp a few feet into the air, and while it’s airborne for a few seconds, the pilots check to make sure it’s balanced and ready to fly.
Then, for the actual takeoff, the crew does its bounce maneuver again while the pilot applies full throttle to the two propeller-equipped engines that pump out as much as 800 combined horsepower. With that, the blimp lumbers into the air for a flight that can last several hours.
In the 1930s, the heyday of the rigid-frame dirigibles that were the forerunners of blimps, gondolas held more people than modern airships can, and carried them in cruise-ship luxury. Some of the old airships held passenger sleeping compartments, observation decks, dining rooms, chefs’ kitchens, showers, and even libraries.
Just as with a hot-air balloon, landing a blimp is not an elegant procedure. The two-person flight crew points the giant gasbag downward toward the mooring area, where the ground crew waits. As the blimp is slightly lighter than air, the pilot must drive it downward with engine power. If both engines quit during this phase of the flight, it’s interesting to note, the blimp wouldn’t crash, but instead would slowly rise higher into the air.
As the blimp nears its mooring mast, a rigid pole rising high off the ground to anchor the blimp, several crew members grab a long rope that hangs permanently from the nose of the envelope. Meanwhile, other members of the crew reach up and grab the gondola hand rail and use their body weight to anchor the blimp while the pilots adjust the helium pressure to give the airship some weight.
Between flights, blimp crew members service the giant machine, which has a habit of swiveling around its mooring mast with the wind like an oversized weather vane. Even on the ground, blimps attract steady crowds of curious onlookers, so that blimp ground crews and pilots spend most of their work hours doing public relations, which for many operators of blimps, such as Goodyear, is precisely the point.