Aerodynamics of Flight Part 3

Question 1

Define Load Factor

Answer 1

Ratio of max load an aircraft can sustain to the gross wight of the aircraft. Measured in Gs

Question 2

Reasons load factor is important

Answer 2

1. Watching out for overload of aircraft’s structures

2. An increased load factor increases stalling speed

Question 3

Maximum bank for average general aviation aircraft

Answer 3

60 degrees

Question 4

Define Va

Answer 4

Design Maneuvering Speed - Maximum speed at which an aircraft may be stalled safely

Question 5

Knowing your Va helps prevent:

Answer 5

Two serious accidents resulting from: stalls from steep turns or excessively maneuvering near the ground.

Structural failures during acrobatics or maneuvers from loss of control

Question 6

Name some relatively high G-load maneuvers:

Answer 6

1. Turns
2. Stalls
3. Spins
4. High speed Stalls
5. Chandelles (max power 180deg climbing turn)
6. Lazy Eights (tracing nose through fig 8 pattern)

Question 7

What is a Vg diagram

Answer 7

Velocity vs G-loads (load factor) diagram

Question 8

When is air incompressible

Answer 8

260 knots; It’s incompressible in that at a fixed altitude, it’s density remains nearly constant while it’s pressure varies

Question 9

What is Critical Mach number?

Answer 9

0.72; When an aircraft reaches the critical Mach number, the speed of the airflow in some areas near the airframe reaches the speed of sound. but does not exceed it.

Question 10

What is a compression wave?

Answer 10

The boundary between the undisturbed air and the region of compressed air is called a shock or compression wave

Question 11

A side effect to high speed flight

Answer 11

Flight controls become harder to control because of airflow over the wing causing separation. Wings are often swept back on aircraft that make constant transonic flights, which tricks the wing into thinking it’s flying slower than it actually is because the wind is not hitting the leading edge at 90 degrees - which delays the formation of shock waves. Ailerons at wing tip become less effective during a stall though

Question 12

What to primary flight controls control?

Answer 12

Elevator
Ailerons
Rutter

Pitch
Roll
Yaw Axes

Question 13

Name some secondary flight controls

Answer 13

Tabs
Leading edge flaps
Trailing edge flaps
Spoilers - speed breaks & helps turn the airfract
Slats

Question 14

What can be used to reduce stall speeds by up to 50 knots

Answer 14

Leading Edge Slots, Slats, & Flaps

Question 15

Load factor is result of what 2 things during a turn

Answer 15

Centripetal force & gravity

Question 16

In sub-sonic aerodynamics, what is the theory of lift based on?

Answer 16

Based upon the forces generated on a body and a moving gas in which it is immersed