Stalling

Question 1

The critical angle of attack has been exceeded when…

Answer 1

The wing can no longer produce enough lift to balance the weight, regardless of airspeed and altitude

Question 2

What is the relationship between velocity and angle of attack (trade off box)

Answer 2

As one increases the other decreases
Increase in the velocity = decrease in angle of attack to maintain lift

Question 3

What happens to the centre of pressure when the AoA is increased

Answer 3

The centre of pressure moves closer to the leading edge up until the critical AoA is exceeded and then it moves down the aerofoil closer to the trailing edge.

Question 4

What is the stall speed for a c172 with and without flaps

Answer 4

47kts (no flaps)
41kts (flaps)

Question 5

What are the 6 conditions do the set stall speeds apply to

Answer 5

MTOW
CoG at FWD limit
Power is idle
Flap retracted
Load factor of 1G
0* angle of bank

Question 6

What are the 6 signs of an incipient stall

Answer 6

High nose attitude
reduced control effectiveness
reduced cockpit noise level
low + decreasing airspeed
airframe vibration (buffeting)
stall warning horn

Question 7

What are the 4 signs of a fully developed stall

Answer 7

Nose drop
aircraft highly unstable
high rate of descent
possible roll (wing drop)

Question 8

Recovery of an incipient stall

Answer 8

Lower nose attitude
Apply power

Question 9

Recovery of a full developed stall

Answer 9

1. Lower nose
2. apply full power
3. rudder to prevent yaw
4. Roll wings to level
5. Smoothly raise nose to normal climb
6. Retract flaps in stages (if applied)

Question 10

What is the HASELL check

Answer 10

Height - sufficient enough to recover by 3000ft AGL
Airframe - configured
Security - no loose items and seatbelts fastened
Engine - temps + pressures in the green
Location - clear of high traffic areas
Lookout - 180* or 2 x 90* turns (physical turns to look for traffic)

Question 11

When do you need to do a HASSEL check?

Answer 11

During the 1st stall in stalling practice

Question 12

What is a HELL check

Answer 12

Height - able to recover by 3000ft AGL
Engine - Temp’s + pressures in the green
Location - out of high traffic areas
Lookout - 180* or 2 x 90* turns

Question 13

When can a HELL check be used

Answer 13

During stalling practice after the 1st stall when the HASSEL check has already been completed

Question 14

What are the forces acting on an aircraft during a stall

Answer 14

Thrust
Drag
Lift
Weight
Tail down force

Question 15

What affect will an increase in weight have on the stall speed

Answer 15

Increase stall speed

Question 16

What affect will an increase in power have on the stall speed

Answer 16

Decrease the stall speed

Question 17

What affect will an extension in flaps have on the stall speed

Answer 17

Decrease the stall speed

Question 18

What angle of attack will an aerofoil stall at with flaps extended

Answer 18

12*

Question 19

Aircraft yawing at the point of stall is called

Answer 19

autorotation

Question 20

What is an incipient spin

Answer 20

When a stalled aircraft begins yawing due to a wing dropping more than the other

Question 21

Recovery from an incipient spin

Answer 21

PARE
Power idle
Aileron neutral
Rudder full opposite
Elevator neutral

Question 22

Recovery from incipient spin once rotation has stopped

Answer 22

Find horizon
Centralize rudder
Positive dive recovery
Power when nose above horizon

Question 23

How to start an approach config stall

Answer 23

1. HASSEL check
2. Carby heat
3. Reduce power 1500RPM
4. Speed check, below 110kts = 1st stage flaps
5. Speed check below 85kts = 2nd stage flaps
6. Stabilize
7. Power idle
8. Stall horn = carry heat cold

Question 24

Recovery of an approach stall

Answer 24

Once stalled…
1. Relieve back pressure to straight and level
2. Full power, right rudder, forward pressure
3. Wait for 65kts, 1st stage of flap up
4. 70kts, raise nose to climbing attitude
5. Best rate of climb, 2nd stage flap up