Podded engine

From Wikipedia, the free encyclopedia

A podded engine is a jet engine in a pod, typically attached below the wing or to the tail of the aircraft.

Currently, almost all large jet airplanes use two or less commonly four jet engines in pods below the wing. Smaller jet airplanes in which placing the jets below the wing would cause them to be too close to the ground instead use two podded engines in the rear of the plane.

As an unusual counter-example, the Hondajet places the podded engines above the wings.

Jet fighters almost never use podded engines, instead typically embedding the engines within the fuselage.

[edit] Advantages

• Podded engines on the wings can act as vortex generators.
• Podded engines hanging from the wing also provide wing bending relief, i.e. as the airflow bends the wings up, the weight of the podded engines resists this, allowing for a lighter structure.
• Podded engines can ease maintance access.
• Podded engines can reduce noise within the cabin (since the engines are farther from the cabin, and for engines mounted below the wing, the wing itself acts as a noise shield).

[edit] Disadvantages

• Podded engines can increase drag.
• A podded engine hanging low from a wing can suffer more damage from foreign objects (i.e., objects can get sucked into a low-hanging jet).
• In a water landing podded engines hanging from the wing increase the stress on the wing, by increasing the amount of drag. This can cause the wings to shear off or flip the aircraft.

[edit] Examples

The first successful design to use podded engines was the Boeing 707.

A Cessna Citation uses two engines podded in the rear.

A Hondajet places the podded engines above the wings.

[edit] Examples of non-podded engines

The De Havilland Comet used engines embedded within the wing.

The F-16 Fighting Falcon uses a turbofan engine embedded in the fuselage.