How Birds Fly
How Birds Fly
One of the requirements for anything that’s heavier than air trying to fly is a structure that combines strength with light weight. This is for birds and it also applies for planes. Birds have many physical features, besides wings, that work together to enable them to fly. They need lightweight, streamlined, rigid structures for flight. The four forces of flight - weight, lift, drag and thrust.
All flying birds have:
o Lightweight, smooth feathers – this reduces the forces of weight and drag o A beak this is instead of having big heavy bony jaws and teeth – this reduces the weight o An enlarged breastbone called a sternum for flight muscle attachments – this helps with the force of thrust o Light bones. Birds bones are very light and hollow. The bones only really have air sacs and very thin crossed bones to make them stronger – this reduces the force of weight o A rigid skeleton to provide firm attachments for powerful flight muscles – this helps with the force of thrust o A streamline body – this helps reduce the force of drag o Wings – these enable the force of lift
Wings
The shape of a bird’s wing are important for producing lift. The increased speed over a curved, large wing area creates a longer path of air. This means that the air is moving more quickly over the top surface of the wing, reducing the air pressure on the top of the wings and making it easier to lift. Also the wings are tilted, so the air gets deflected down causing a reaction force, opposite direction creating lift.
Larger wings produce greater lift than smaller wings. Smaller-winged birds have to fly faster to keep the same lift as birds with larger wings.
Wing loading tells you how fast a bird must fly to be able to lift. The wing load is weight/wing area. A smaller wing load means that the bird can fly slower to maintain lift.
Gliding
When a bird is gliding it doesn’t have to do anything at all. The wings are held out from their body and
One of the requirements for anything that’s heavier than air trying to fly is a structure that combines strength with light weight. This is for birds and it also applies for planes. Birds have many physical features, besides wings, that work together to enable them to fly. They need lightweight, streamlined, rigid structures for flight. The four forces of flight - weight, lift, drag and thrust.
All flying birds have:
o Lightweight, smooth feathers – this reduces the forces of weight and drag o A beak this is instead of having big heavy bony jaws and teeth – this reduces the weight o An enlarged breastbone called a sternum for flight muscle attachments – this helps with the force of thrust o Light bones. Birds bones are very light and hollow. The bones only really have air sacs and very thin crossed bones to make them stronger – this reduces the force of weight o A rigid skeleton to provide firm attachments for powerful flight muscles – this helps with the force of thrust o A streamline body – this helps reduce the force of drag o Wings – these enable the force of lift
Wings
The shape of a bird’s wing are important for producing lift. The increased speed over a curved, large wing area creates a longer path of air. This means that the air is moving more quickly over the top surface of the wing, reducing the air pressure on the top of the wings and making it easier to lift. Also the wings are tilted, so the air gets deflected down causing a reaction force, opposite direction creating lift.
Larger wings produce greater lift than smaller wings. Smaller-winged birds have to fly faster to keep the same lift as birds with larger wings.
Wing loading tells you how fast a bird must fly to be able to lift. The wing load is weight/wing area. A smaller wing load means that the bird can fly slower to maintain lift.
Gliding
When a bird is gliding it doesn’t have to do anything at all. The wings are held out from their body and