Exam 4 Review Flashcards
Movement around the longitudinal axis is called:
Roll
Movement around the lateral axis is called:
Pitch
Movement around the vertical axis is called:
Yaw
What is Dynamic Stability?
An objects tendency to return to its previously undistrubed state OVER TIME
What is Static Stability?
INITIAL tendency of an object to return to its previously undisturbed state
What is a Phugoid?
- Aircraft motion where attitude, pitch and airspeed vary widely
- Interchangeable between Kinetic and Potential Energy
- *Tail Stalls Out**
Explain Dutch Roll
Coupled lateral/directional oscillation that is “Out of Phase”
Name 2 types of stability that increase when we sweep the wings back
- Side Slip
2. Static
What is the Rate equation?
Rate (deg per sec) = 1091(tan BA)/V
What is the Radius equation?
Radius (feet) = V^2/11.26(tan BA)
What is the Load Factor equation?
n (Gs) = 1/(cos BA)
_____ static stability leads to ALL dynamic stability.
POSITIVE static leads to ALL dynamics
If an a/c’s controls are bumped and the plane returns back to its OG state, it has what kind of stability?
POSITIVE STATIC
If an a/c’s controls are bumped and the plane remains steady in the new position, it has what kind of stability?
NEUTRAL STATIC
If an a/c’s controls are bumped and the plane continues away from its OG state, it has what kind of stability?
NEGATIVE STATIC
If an a/c’s controls are bumped and the planes displacement reduces over time back to its OG state, it has what kind of stability?
POSITIVE DYNAMIC
If an a/c’s controls are bumped and the planes displacement remains constant over time, it has what kind of stability?
NEUTRAL DYNAMIC
If an a/c’s controls are bumped and the planes displacement increases over time away from its OG state, it has what kind of stability?
NEGATIVE DYNAMIC
What are 2 causes of ROLL due to YAW?
- Speed difference of wings
2. Rolling moment on the vertical tail
What do we call YAW due to ROLL?
Adverse Yaw
What results when an a/c BANKS w/o a turn?
- Side Slip
2. Keel effect?
When we trim the elevator, what are we trimming to maintain?
Airspeed
How is LATERAL stability achieved?
- Dihedral
- Keel Effect
- Sweepback
What gives stability around the VERTICAL axis?
Vertical tail (Fin and Rudder)
What gives stability around the LONGITUDINAL axis?
- CG
- Horizontal Stabilizer
(Pitch stability)
- Stability around the lateral axis
What gives movement around the vertical axis?
Rudder
What gives movement around the longitudinal axis?
Ailerons
What gives movement around the lateral axis?
Elevator
List 6 things that give longitudinal stability?
- CG
- Weight
- Lift
- Tail
- Canard
- Pitch stability
Why do manufacturers add a Dorsal Fin to an airplane?
- Gives SIDE FORCE to have nose chase into the Relative Wind
- Helps to get out of spins
You’re in a 43 degree bank angle, IAS is 137 knots and the plane weighs 6,300 lbs. Find load factor, rate of turn and radius of turn!
Load Factor = 1.37 Gs
Rate = 7.43 degrees per second
Radius = 1,787.5 ft
When would an a/c become “Out of Phase”
During a Dutch Roll
What does Dihedral help with?
Lateral Stability
What do Sweepback wing help with?
Lateral Stability when banking
What IS dihedral? How does it work?
- The upward angle of an a/c’s wings from the fuselage
- Lower wing flying at a higher AOA, increases lateral stability when banking
What is Keel Effect?
The result of sideforce-generating surfaces being above/below the CG in an a/c
4 ways lateral stability is designed into a/c
- Dihedral
2 sweepback - Keel
- Vertical wing placement
