Chapter 5: Flight Part 2

Question 1

2 Types of Non powered flight

Answer 1

• Gliding and Soaring

Question 2

Name 2 types of Soaring

Answer 2

• static soaring and dynamic soaring

Question 3

Name 2 types of Static Soaring

Answer 3

• thermal soaring(on rising thermals) and slope soaring (on rising air along a slope)

Question 4

Gliding Flight

Answer 4

• non-powered
• losing altitude over time, constant flight speed
• used by birds with any wing shape

Question 5

How do birds restore stability during passive gliding?

Answer 5

• if sudden wind gust causes bird to roll, it will slide slip down and to the right
• as this occurs, angle relative to the wind velocity increases on one wing and the effectve lift is greater on the other wing
• this together creates a restorative roll to the left

Question 6

Describe how static soaring coccurs by thermals

Answer 6

• Exploit columns of warm air that rise when the ground is heated by the sun
• Have slots between the primary flight feathers at the tip of the wing
• Permit each primary to act as an individual “winglet:” reduces the induced drag of the wing tip by redistributing the trailing vortices horizontally and vertically
  (circle of air generates lift)

ex: vultures, hawks, eagles

Question 7

Describe the process of Static soaring while in flight

Answer 7

• a soaring bird circles upward with the column of rising air
• Then glides down to the base of another adjacent thermal - allows the bird to cover great distances with minimal energy
• birds with slotted-high lift wings

Question 8

Soaring

Answer 8

• nonpowered flight
• gliding with no loss in altitude, either horizontal or rising flight

Question 9

Dynamic Soaring

Answer 9

• bird uses wing speed gradients and its own momentum
• used by birds with high-aspect ratio wings
• Turning into the wind to gain altitude and then gliding down across the wind to gain speed
• wing current heading towards them helps generate lift

Example: Sea birds, can fly continuously across the wind without any expenditure of mechanical energy by alternating their flight direction in an S-pattern

Question 10

Powered Flight

Answer 10

• flapping, bird provides thrust
• most often used by birds with elliptical or high-speed wings

Question 11

Describe the Ring Vortex

Answer 11

• Taking off and at slow speeds when the induced drag is high
• force only used in downstroke, upstroke dynamically passive

Question 12

Describe the Continuous Vortex

Answer 12

• used in faster forward flight
• vortex between upstrokes AND downstrokes

Question 13

How can the tail restore stability in flight?

Answer 13

• it steers like a steering wheel
• it restores torque and moves the yaw angle back to the flight velocity pathway
• removes unequal drag

Question 14

What is the only type of bird that can hover under its own power and how does happen?

Answer 14

• hummingbird
• consistent hovering from
• wings beat vertically during forward flight to generate forward thrust
• In hovering flight, the wings beat horizontally in the pattern of a flattened figure eight
  (backwards flight: tilts angle of wing action and inverts camber of wing to create rear-directed thrust0

Question 15

What are the two main types of intermittent flight?

Answer 15

• flap gliding and flap bounding

Question 16

Flap-gliding

Answer 16

• is most energetically beneficial at slow and moderate flight speeds
• typical of larger bird
• straight pathway fliying

Question 17

Flap-bounding

Answer 17

compared with continuous flapping, may save power at faster flight speeds
- best in small or mid-sized birds
- curved fliying

Question 18

Aspect ratio

Answer 18

• The square of wing span (the distance from tip to tip of the open wings) divided by the total wing area

Question 19

What is wing loading?

Answer 19

• relationship between body mass and wing area
• the mass of a bird divided by the total area of the upper surface of its wings

Question 20

Where does most of the thrust come from in take-off?

Answer 20

• the hindlimbs

Question 21

How do birds use their wings to land?

Answer 21

• they have an increased “angle of attack, “ stall controlled as they turn from horizontal to vertical before landing on feet

Question 22

Why are most bird bones pneumatic?

Answer 22

• the bones are weight efficient/ lightweight in order to provide flight
• some/most bones in a bird are hollow/ have LARGE air spaces

(however, flightless birds have heavy, less pneumatic bones)