Stability And Control

Question 1

Static Stability

Answer 1

Driving force on an object that displaced it from equilibrium

Question 2

Positive Static Stability

Answer 2

Initial tendency to return to equilibrium

Question 3

Neural Static Stability

Answer 3

Stays in the same place after driving force removed

Question 4

Negative Static Stability

Answer 4

Initial tendency to diverge

Question 5

Static Stability on controllability

Answer 5

Higher static stability resists forces from controls less manoeuvrable

Question 6

Positive Dynamic Stability

Answer 6

Subsequent displacement with time either oscillation to return point or slowly returns to its starting point.

Question 7

Neutral Dynamic Stability

Answer 7

No damping forces continues oscillating after driving force

Or

Once driving force is removes stays in the same place

Question 8

Dynamic Instability

Answer 8

Ball continues to be displaces after the driving force is removed

Question 9

Dynamic stability is associated with which static stability forces

Answer 9

Positive static force required

Question 10

Dynamic Neutral is associated with what static stability

Answer 10

Static neutral
Static stablility

Question 11

Dynamic Instability associated with what static stability levels

Answer 11

Static stability
Static instability

Question 12

Aerodynamic Centre

Answer 12

Point on aerofoil where the size of wing moment remain constant for AOA

Question 13

Aerodynamic Centre of symmetrical aerofoil

Answer 13

25% chord

Question 14

Aerodynamic Centre on cambered aerofoil

Answer 14

23%-27% chord depending on cross sectional shape

Question 15

Absolute Angle of attack

Answer 15

Angle between the RAF and the aerofoil zero lift line

This is usually above the chord line on a cambered wing

Question 16

Fly By Wire control law

Answer 16

Normal Law - flight envelop protection

Alternate Law - removal of some handling envelopes

Direct Law - pilots controls and control surfaces 1 to 1

Question 17

Soft Envelope Protection

Answer 17

System gradually increases control forces with speed etc
Boeing type

Question 18

Hard envelope protection

Answer 18

System is in control
Airbus

Question 19

CM+

Answer 19

Pitch up

Question 20

CM-

Answer 20

Nose Down