AER 4: Practical Application Flashcards
Define Center of gravity
The point of the aircraft the which the force of weight acts. This changes each flight due to adjustments in weight and balance.
Rudder
Located on the vertical stabiliser. Yaw (left and right), acts along the vertical axis. Secondary effect is roll. provides directional stability
Ailerons
Located trailing edge outer wings. Roll (bank to the left or right), acts along the longitudinal axis. Secondary effect is yaw. Provides lateral stability.
Elevators
Located on the vertical tail section. Pitch (nose up and down), acts along the lateral axis. Nil secondary effect. Provides longitudinal stability.
Define Stability
The reaction of a body that has been disturbed by an outside force
Define Static stability
Immediate reaction
Define Dynamic stability
Subsequent reaction
Positive Static stability
The object attempts to return to its original position - Stable
Neutral static stability
The object stays in its new position
Negative static stability
The object continues to move in the new direction. (unstable)
Positive dynamic stability
The object eventually returns itself to its original position
Neutral dynamic stability
The object moves continuously, equating to an un dampened pendulum effect - never stopping.
Negative dynamic stability
The object continues to move, increasing in magnitude of displacement as time increases.
What can aircraft stability be controlled by?
- Primary controls
- Wing design (Anhedral or Dihedral)
- Wing position (High/Low/Swept)
- Center of gravity
What are the forces in S & L flight?
L = W and T = D
The forces are in equilibrium as the aircraft is not accelerating.
What are the forces in a climb?
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.
Explain Max angle of climb
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.
Explain Max rate of climb
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.
Define Excess thrust
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.
What are the forces in descent?
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).
What are the forces in a turn?
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.
What are some symptoms of a stall?
- High nose attitude
- Reduced airspeed
- Slippery/less effective controls
- Buffet
- Stall warning
- Stall
- Potential drop of a wing.
How do you recover from a stall?
- Nose down
2. Max power
What factors can increase the stall speed?
- Increase in weight
- 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.
Define Accelerated Stall
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.
Define Asymmetric Flight
The condition applying to multi - engine aircraft, following the loss of power from an engine(s) mounted laterally either side of the centre line.
How does asymmetric flight affect performance?
50% power drop (i.e. a loss of power from one of two engines), results in an 80% drop in performance.
How is steady flight achieved in asymmetric flight?
- Failed engine shut down and feathered
- Gear and flap retracted
- 5 Degree bank towards live engine (to compensate for drag produced by failed engine)
- Limitation on bank angle.
Forces in a glide descent?
L + D = W
