AER 4: Practical Application

Question 1

Define Center of gravity

Answer 1

The point of the aircraft the which the force of weight acts. This changes each flight due to adjustments in weight and balance.

Question 2

Rudder

Answer 2

Located on the vertical stabiliser. Yaw (left and right), acts along the vertical axis. Secondary effect is roll. provides directional stability

Question 3

Ailerons

Answer 3

Located trailing edge outer wings. Roll (bank to the left or right), acts along the longitudinal axis. Secondary effect is yaw. Provides lateral stability.

Question 4

Elevators

Answer 4

Located on the vertical tail section. Pitch (nose up and down), acts along the lateral axis. Nil secondary effect. Provides longitudinal stability.

Question 5

Define Stability

Answer 5

The reaction of a body that has been disturbed by an outside force

Question 6

Define Static stability

Answer 6

Immediate reaction

Question 7

Define Dynamic stability

Answer 7

Subsequent reaction

Question 8

Positive Static stability

Answer 8

The object attempts to return to its original position - Stable

Question 9

Neutral static stability

Answer 9

The object stays in its new position

Question 10

Negative static stability

Answer 10

The object continues to move in the new direction. (unstable)

Question 11

Positive dynamic stability

Answer 11

The object eventually returns itself to its original position

Question 12

Neutral dynamic stability

Answer 12

The object moves continuously, equating to an un dampened pendulum effect - never stopping.

Question 13

Negative dynamic stability

Answer 13

The object continues to move, increasing in magnitude of displacement as time increases.

Question 14

What can aircraft stability be controlled by?

Answer 14

1. Primary controls
2. Wing design (Anhedral or Dihedral)
3. Wing position (High/Low/Swept)
4. Center of gravity

Question 15

What are the forces in S & L flight?

Answer 15

L = W and T = D

The forces are in equilibrium as the aircraft is not accelerating.

Question 16

What are the forces in a climb?

Answer 16

L < W and T >D
The aircraft is not accelerating, however it is maintaining the IAS in its climb.
More thrust is required to overcome the drag element and also to lift the aircraft’s weight at a vertical speed.
Thrust is the biggest element in a climb.

Question 17

Explain Max angle of climb

Answer 17

Is used for collision avoidance, achieving maximum ANGULAR clearance in the shortest possible time. Equals a steeper climb gradient with minimum drag and maximum THRUST.

Question 18

Explain Max rate of climb

Answer 18

The best climbing speed (max rate of climb) is that
at which the excess power/thrust is at a maximum; so that, after expending some power in overcoming the drag, the maximum amount of power remains available for climbing the aircraft.
Not Max power, more efficient and takes a longer distance to reach the same flight level than Max Angle of climb would.

Question 19

Define Excess thrust

Answer 19

Is the difference between the power/thrust available and the power/thrust required by the aircraft to overcome drag. This is marked on the Drag/Thrust graph as the largest distance between the two curves.

Question 20

What are the forces in descent?

Answer 20

L < W
D > T
L + D = W
L + D = W + T
The nose down attitude of the aircraft assists descent by pushing weight forward
Adding power flattens the descent before landing (flare).

Question 21

What are the forces in a turn?

Answer 21

L > W and T = D
During the turn, the pilot must increase the AoA to maintain S & L flight, otherwise the lift force will be too small to balance the weight and the aircraft will descend.
As Angle of bank increases, so must the AoA to maintain S & L. Thrust and Drag are equal as the IAS stays the same.

Question 22

What are some symptoms of a stall?

Answer 22

• High nose attitude
• Reduced airspeed
• Slippery/less effective controls
• Buffet
• Stall warning
• Stall
• Potential drop of a wing.

Question 23

How do you recover from a stall?

Answer 23

1. Nose down

2. Max power

Question 24

What factors can increase the stall speed?

Answer 24

1. Increase in weight
2. Increase load factor (Pulling G through manoeuvering)
   Increasing the stall speed is not bad as long as the crew are aware that this increase will result in a smaller buffer between current IAS and stall speed. This can be countered by increasing the current IAS.

Question 25

Define Accelerated Stall

Answer 25

A stall that occurs due to the aircraft experiencing a load factor higher than 1G (for example, whilst pulling up from a dive). During this time the aircraft stalls at a higher speed than the normal stall speed.

Question 26

Define Asymmetric Flight

Answer 26

The condition applying to multi - engine aircraft, following the loss of power from an engine(s) mounted laterally either side of the centre line.

Question 27

How does asymmetric flight affect performance?

Answer 27

50% power drop (i.e. a loss of power from one of two engines), results in an 80% drop in performance.

Question 28

How is steady flight achieved in asymmetric flight?

Answer 28

1. Failed engine shut down and feathered
2. Gear and flap retracted
3. 5 Degree bank towards live engine (to compensate for drag produced by failed engine)
4. Limitation on bank angle.

Question 29

Forces in a glide descent?

Answer 29

L + D = W