Blimps work as lighter-than-air aircraft called airships that float because they are filled with a gas lighter than air, typically helium. The helium inside a blimp's large airtight envelope makes it buoyant so the blimp rises in the air. Unlike balloons, blimps have engines and control surfaces (rudders and elevators) to steer and maneuver. Inside the envelope, air-filled ballonets are inflated or deflated to control altitude and maintain the blimp's shape. The engines provide thrust to move the blimp forward, and the pilot adjusts the flight controls to navigate, ascend, or descend.

How lift is generated

• The helium gas inside the blimp is less dense than the surrounding air, providing lift by positive buoyancy.
• The pilot controls ascent and descent by adjusting air volume in ballonets inside the envelope, which changes overall weight and buoyancy.

Structure and Control

• The blimp has a large envelope made of airtight fabric to hold helium.
• It has no rigid internal frame, relying on internal pressure to maintain shape.
• Movable rudders and elevators steer and adjust pitch.
• Engines on the gondola generate thrust for forward and backward movement.

Flight operation

• Ballonets inflate or deflate to keep the envelope taut as helium expands or contracts with altitude.
• Throttle and control surfaces let the pilot angle the blimp into the wind for controlled navigation.
• The blimp can hover, travel at slow speed, and stay aloft for long periods.

Blimps are commonly used for advertising, surveillance, and event coverage due to their ability to hover and cruise slowly with stable flight.