Aerodynamik KAP 10+11+(12) Stability & controls

Question 1

What happens to controllability when stability increases ?

Answer 1

Decreases

Question 2

When and aircraft is in equilibrium the sum of all forces and moments are ___ about the ____

Answer 2

Zero CG

Question 3

Why do we use control imputs ? (relation to stability)

Answer 3

To overcome the aircrafts stability

Question 4

What is the general difference between static and dynamic stability ?

Answer 4

Static: Immediate respons when displaced from equilibrium

Dynamic Respons over time

Question 5

Both static and dynamic stability have 3 categories - what are those ?

Answer 5

Positive - neutral - negative (instability)

Question 6

What happens when an object is
Positive - neutral - negative
static stabile ?

Answer 6

Positive = ∪ Falls back in the bowl

Neural = — Stays where it is

Negative = ∩ Continues falling over the edge

*Can be more of less stable : The higher the bowl - the more stable - the more energy needed

Question 7

What happens when an object is
Positive - neutral - negative
dynamic stabile ?

Answer 7

Positive : Falls back in the bowl

Neutral : Keeps swinging in up and down the bowl with the same fluctuation

Negative : Self-reinforcing - the swing becomes more and more

Question 8

Planes approved by the EASA HAS TO BE ___ ? (stability)

Answer 8

Static stabile

Question 9

Longitudinal static stability

The distance between CG & AC

The larger distance the ____ stabile the plane is

Answer 9

the less stabile the plane is

Question 10

How do we maintain equilibrium ?

Answer 10

Continuous pilot input or trim

Question 11

Where is the AC on a

symmetrical section ?

Asymmetrical section

Answer 11

25% of chord

23-27% chord

Question 12

A ___ CG increases static stability

Answer 12

Forward

Question 13

What is load limit ?

Answer 13

The maximum load to be experienced in service

Question 14

What is ultimate load ?

Answer 14

The FAILING load of the structure

Question 15

What is the factor of safety ?

Answer 15

Ratio : Ultimate load to the limit load

Question 16

What is the load factor in level flight. ?

Answer 16

1 ( Lift = weight )

Question 17

The load factor is the ratio of ____ to _____

Answer 17

Lift to weight

Question 18

What is the limit load factor based on ?

Answer 18

The maximum take-off weight

Question 19

What is the safety factor (load factor) for aeroplanes ?

Answer 19

1.5 (If it can pull 6G it actually can pull 9G at which it fails)

Question 20

What is displayed on the maneuvering envelope ?

Answer 20

Load factor vs. IAS

Question 21

Below which speed limit is it only possible to stall the aircraft (not distort/fail)

Answer 21

Va

Question 22

Does weight have an effect on Va ?

Answer 22

Yes - higher Va

(Heavy = stall early = fly faster)

Question 23

What is Vne determined by ?

Answer 23

Flutter

Question 24

Below which speed can full elevator deflection be made without exceeding the limit load factor ?

Answer 24

Va

Question 25

The planes axis all go through

Answer 25

The CG

Question 26

Lateral stability is around the ____ axis

Answer 26

Roll

Question 27

Longitudinal stability is around the ____ axis

Answer 27

Pitch

Question 28

Directional stability is around the ____ axis

Answer 28

Yaw

Question 29

What happens to the dist. between CP & AC when lift increases ?

Answer 29

Decreases

Question 30

High mounted wing increases ___ stability

Answer 30

Lateral static stability

Question 31

Longitudinal stability increases with:

Answer 31

1. ^ distance CG & Tailplane
2. Forward CG

Question 32

Which is a major factor to longitudinal stability ?

Answer 32

The tailplane

Question 33

CG max. forward / CG max. rear of neutral point
What happens ?

Answer 33

Forward: Maximum longitudinal stability

Rear: Weakest acceptable stability

Question 34

When CG is moved forward - Static longitudinal stability ____

Answer 34

Increases

Question 35

Stability __ with altitude

Answer 35

Decreases