Efficient Eagles

Soaring birds adjust their wingtips so they can glide effortlessly.

Soaring birds such as buzzards, eagles and storks have special feathers on their wing tips. As they fly, the feathers on the tips of those large wings curl up until they're nearly vertical. This prevents air from below the wing curling up to create friction on top of the wing. In this way, the wings experience an upward force called lift.

With their wingtip adaptation, soaring birds require less energy for flying. How does this work?

This activity can be used to explore how shape influences performance of flight.

• Ask pupils to choose a bird that they find interesting and draw a picture of it on a piece of paper. You might wish to cut out some images of birds in advance for pupils to choose from; select images of birds that are able to soar really well such as eagles, vultures and storks.
• Next, ask them to identify the unique features on the bird's wings that help it fly (such as the shape of the wings, the feathers, etc).
• Using the picture they drew as a guide, ask pupils to create a paper airplane that incorporates the unique features of the bird's wings. For example, they could add wingtips or flaps to the wings.
• Once they have created their paper airplane, let them test it to see how well it flies. How far does it go, how fast and in what direction? Which airplanes flew the best, and which the worst? Why?
• As they test their paper airplanes, discuss how the unique features of the bird's wings have inspired the design of airplanes.
• Encourage pupils to experiment with different designs and features to see how they affect the flight of their paper airplanes. What happens with each change they make to their plane design?

Simple explanation

Wingtips are the tips of a bird's wings and they help the bird to fly more efficiently. The wingtips of many birds have a special shape that affects the air around them as they fly. The end of their wings go up in a certain angle, which helps to reduce turbulence and drag. This is important for birds because it allows them to fly for longer distances and use less energy when they are hunting for food or flying to their nests.

More detailed explanation

The curled wingtips of birds serve several important functions related to flight:

1. Improved lift: The shape of the wingtips affects the flow of air over the wings. The curled shape of the wingtip creates a vortex of air that helps to increase the lift generated by the wing. The wingtips prevent the air moving over the upper surface of the wing to separate from the wing surface, which generates a lower pressure on its upper surface and a higher pressure on its lower surface.
2. Enhanced control: Wingtips allow birds to control their lift during flight, which can be useful for takeoff and landing. By adjusting the angle of their wingtips, birds can also improve maneuverability; it allows them to make sudden movements in the air, and change direction more quickly and easily.
3. Reduced turbulence: The curled shape of the wingtip also helps to reduce turbulence, which can improve the overall efficiency of flight. By reducing turbulence, the bird can fly more smoothly and conserve energy.

Wingtips on airplanes can provide several sustainability benefits:

1. Improved fuel efficiency: wingtips can reduce drag and improve lift, leading to improved fuel efficiency and reduced emissions.
2. Improved stability: the upward bend of the wingtips creates vortexes that stabilize the aircraft and prevent it from rolling excessively.
3. Reduced noise pollution: wingtips can also reduce the noise generated by aircraft during takeoff and landing, reducing noise pollution near airports.
4. Increased payload capacity: by reducing drag and improving lift, wingtips can increase the payload capacity of an aircraft, allowing for more efficient use of resources.
5. Reduced maintenance costs: wingtips can also reduce the wear and tear on an aircraft's engines, potentially reducing maintenance costs and extending the lifespan of the aircraft.

Overall, wingtips can contribute to a less damaging aviation industry through improved efficiency, reduced emissions, and reduced impact on the environment. By requiring less energy, running planes on new forms of cleaner energy may be possible.

Some STEAM opportunities include:

• Identify the effects of air resistance and friction, that act between moving surfaces.
• Analyse advantage and disadvantage of different adaptations/behaviours.
• Asking questions and making observations.
• Carrying out simple tests.
• Making predictions.
• Using scientific evidence to answer a question.
• Apply learning to real world problems.

Difference wingtips and winglets:

Wingtips and winglets are aerodynamic devices attached to the wings of an aircraft. Wingtips are extensions of the wing at the outermost part of the wing that curve upward or downward. Wingtips can improve the fuel efficiency of the aircraft by reducing drag and increasing lift. Winglets, on the other hand, are vertical fins that are attached to the end of the wingtips. Winglets work by reducing the turbulence created at the wingtip, which helps to reduce drag and increase fuel efficiency. Winglets are more effective than wingtips in reducing drag and increasing fuel efficiency.

Watch how plane wings work (watch here).

Read about how plane wings work (read more here).

How have birds inspired plane wings (read more here).

Airplanes have another adaptation, inspired by owls. The fringes on the edges of owl feathers help to break up the airflow over the surface of the wings, which reduces turbulence and noise. This feature has been replicated in the design of airplane wings to improve their aerodynamic efficiency and reduce noise during flight (watch here).