Stalling

Question 1

How does the centre of pressure move as the angle of attack is increased?

Answer 1

The centre of pressure moves towards the leading edge with an increase in angle of attack

Question 2

What is a stall?

Answer 2

When the aerofoil has exceeded its critical angle of attack and can no longer produce enough lift to balance weight

Question 3

An aircraft can stall regardless of:

Answer 3

Regardless of airspeed and attitude

Question 4

What are the stall speeds for the C172N? (flaps and clean)

Answer 4

Clean: 47kts
With flaps: 41kts

Question 5

How does the stagnation point move as the AoA increases?

Answer 5

The stagnation point moves along the bottom of the aerofoil closer to the trailing edge

Question 6

How does the force of lift change in a stall?

Answer 6

In a stall lift moves aft of the CoG and decreases in magnitude

Question 7

How does an increase in weight affect stall speed?

Answer 7

Increases stall speed

Question 8

How does a decrease in weight affect stall speed?

Answer 8

Stall speed decreases

Question 9

How is stall speed affected as the CoG moves aft?

Answer 9

the stall speed decreases

Question 10

How does an increase in power affect stall speed?

Answer 10

Reduces stall speed

Question 11

How does flap extension affect stall speed?

Answer 11

Reduces stall speed

Question 12

How does an increase in load factor affect stall speed?

Answer 12

Increases stall speed

Question 13

What is the HASELL check?

Answer 13

MUST BE DONE BEFORE GOING INTO A STALL

Height - make sure you can recover by 3000’ AGL
Airframe configured - clean
Security - no loose articles
Engine T’s and P’s in the green
Location - clear of high traffic areas
Lookout - 180* turn or two 90* turns

Question 14

What are the symptoms of an incipient stall?

Answer 14

These can occur in any order and may or may not be present

(RSLURP)
Reduced cockpit noise level
Stall warning
Low and decreasing airspeed
Unusually high nose attitude
Reduced control effectiveness
Possible buffeting on the tail

Question 15

What are the symptoms of a full developed stall?

Answer 15

(HAWN)
High rate of descent
Aircraft highly unstable
Wing drop possibly
Nose drop

Question 16

How do you recovery from an incipient stall?

Answer 16

Lower the nose attitude
apply power

Question 17

How do you recover from a fully developed stall?

Answer 17

Carby heat cold
simultaneously release back pressure and introduce power
at 65kt, first stage of flaps up
at 70kt, raise nose to Vy
Once positive rate of climb established, retract another stage of flaps
retain target altitude

Question 18

How do you enter a stall in approach configuration?

Answer 18

carby heat on
1500RPM
speed checked below 100kt first stage of flaps
below 85kt, second stage of flaps
reduce power to idle
increase back pressure to maintain level

Question 19

What is the recovery from a spin?

Answer 19

PARE
Power idle
Aileron neutral
Rudder full opposite
Elevator through neutral

Once rotation has stopped:
centralise rudder
dive recovery
power above the horizon