Flying - A Very Natural Occurrence - Introduction

Introduction

page 1

Although mechanical flight, as we know it today, has been in existence for less than 100 years, natural flight has existed for millions of years. Long before man appeared on this planet, leaves and seeds moved through the air in gliding flight. Later, insects, dinosaurs, birds, and bats achieved true flight.

Gliding Flight

As seeds disperse to find the perfect growing places they too seem to "fly" with the wind. Some, like dandelion seeds and milkweed pods have parachutes made of fine hairs which let them "fly" many miles through the air. Other seeds, like maple and ash, have helicopter "wings" that enable them to be whirled for long distances. But seeds are not considered true flyers. Seeds are considered gliders because they do not have flapping wings to propel them through the air.

"Flying" fish achieve flightlike movements by means of large pectoral fins that serve as wings. Some amphibians and reptiles that glide through the air include "flying" frogs, lizards, and snakes. Webbing between the toes or extended flaps of abdominal skin make the necessary parachute that enable them to glide. The golden tree snake of the Malayan Peninsula can "fly" from a tree to surprise its prey or an enemy.

Gliding mammals such as the "flying" squirrels of Asia, North America and Europe use the furry membrane between their outstretched limbs to "parachute" from tree to tree using their long tails as rudders for maneuvering.

Although true flyers some birds, like hawks and vultures, also glide and soar to rest their wings and conserve energy. As they glide, they drop lower and lower until finally they must start flapping again to stay up in the air. At other times, they soar higher and higher for hours on warm air currents called thermals.

True Flight

True flight was achieved between 250,000,000 to 65,000,000 years ago by the pterosaurs (Greek for feather winged lizard). While the most well-known of these flying dinosaurs is the Pterodactyl, the largest of the pterosaurs was the North American Quetzalcoatlus with a wingspan of 40 feet from tip to tip . That is as wide as some planes today.

True flight in the natural world of today is accomplished only by insects, birds, and bats. They are the only animals who are able to propel themselves through the air for a sustained period of time by flapping their wings.

Insects, the first creatures to develop wings, are the oldest known true flyers. Their tiny, but powerful, muscles allow most insects to twist and sway their wings in figure eights, thus enabling them to fly forward, hover, or even fly backwards.


Insect Trivia:: A dragonfly flaps its two pairs of wings alternately, the front ones rising as the rear ones fall. Although bees' wings seem too small to enable flight, their rapid beats of over 100 times a second allow them to move forward, backward and up and down. A housefly can somersault in flight to land upside down on a ceiling.

While insects are considered the most maneuverable of all flying creatures, birds are considered nature's perfect flying machines. Every part of a bird is adapted to flying. Their bodies are as streamlined as an airplane, enabling them to slip easily through the air. Their bones are strong, yet lightweight, because they contain many air sacs. The chest muscle, which operates the wings, is extremely large and powerful. Their wings are covered in tightly fitting feathers that trap air.

The feathers have a stiff, straight part running through them called a shaft. On both sides of the shaft are vanes composed of barbs which are held together by barbules. The bird's wings, with each of its feathers, are shaped much like an aircraft's wing--curved on top and flatter underneath. This allows both wings to achieve lift in the same way.


Bird Trivia:: Most birds fly at low altitudes below 300 feet and only a few dozen species fly higher than 3,000 feet.; A world altitude record of 37,000 feet was set by a Ruppell's vulture that collided with a commercial aircraft over the Ivory Coast.; The fastest flying creatures in level flight are ducks and geese, while the peregrine falcon is found to be the fastest when diving from great heights.

Of the nearly 4,000 mammal species on earth, bats are the only mammals capable of powered flight.


Bat Facts:: Bats make up one fourth of all mammal species and are second in diversity only to rodents. More bats are found in the tropics than any other mammal.; The large ears and nose leaves of some microbats aid in echolocation.; While most humans are unable to hear the ultrasonic beeps of bats, some children can. Some moths can hear the ultrasonic pulses of bats and will change their flight path or drop to the ground in order to evade capture. Others, like the Tiger moth, will click back to resemble ultrasonic bat calls to confuse bats into thinking they are another bat.

Bats belong to the animal order chiroptera (Greek for hand-wing). Their wing structure is very different from that of birds and insects. A bat's wing is composed of a thin, fleshy membrane stretching from the elongated bones of the forearm to the bat's legs (and sometimes tail). The membrane is supported by elongated finger bones; hence, the name "hand-wing". This wing structure enables bats to move their wings much like we move our fingers. As they fly they can flip and turn quickly often using their wings independently of each other. Like insects, bats are expert acrobatic fliers.

True flight in the natural world is achieved by the presence of wings. But wings, while making these animals similar, also make them unique. As hard as he tried, man could not imitate animal flight. It was his brain that eventually enabled him to fly.

Web Hosting Provided By The National Business Aviation Association.

Explore Space ... Not Drugs!
Hear what astronauts have to say about staying drug-free.
Last modified: Mon Jul 7 10:48:38 PDT 1997