Turning And Stalling Flashcards
(52 cards)
1
Q
Force acting towards the centre of the turn
A
Centripetal force
- Keeps the aircraft turning
- Centrifugal opposes
2
Q
Force that opposes lift increases a turn
A
Loading
3
Q
Opposite to vertical component of lift
A
Weight
4
Q
Load factor
A
- The ratio of lift upon weight
- Load factor = lift/weight
- AKA apparent weight
5
Q
Effect of load factor on the angle of bank
A
Load factor = 1/cos angle
E.g. Load factor = 1/cos 60
= 1/0.5 = 2G
6
Q
30 degree AoB
A
= 1.15g
7
Q
45 degree AoB
A
= 1.41G
8
Q
60 degrees angle of bank
A
= 2G
9
Q
Effect of stall speed
A
- Load factor increases the stall speed significantly
10
Q
30 degree AoB =
A
7% increase
11
Q
45 degree AoB =
A
19% increase
12
Q
60 degree AoB =
A
41% increase
13
Q
75 degree AoB =
A
100% increase
14
Q
Stall speed calculation formula
A
New stall speed = basic stall x root(load factor)
15
Q
Design manoeuvre speed
A
The speed at which, when increasing the angle of attack, the max loading is reached before stalling, resulting in airframe damage
16
Q
What happens when the angle of bank is increased?
A
- Lift is tilted further towards the centre of the turn - increases centripetal force
- Radius is smaller, turn is tighter
17
Q
What effect does airspeed have on a turn radius?
A
- Increased airspeed = greater turn
- Reduced airspeed = smaller turn
18
Q
What effect does altitude have on a turn?
A
- Performance of a turn is based on the IAS of an aircraft
- Rate and radius are based on the TAS
- With an increase in altitude, an aircraft will execute a turn with a greater radius and slower rate of turn
19
Q
What effect does weight have on a turn
A
- Does not directly effect rate and radius
- Limits the max rate of turn and min radius of turn due to the requirement of more lift
20
Q
Rate 1 turn
A
- 3 degrees per second
- 180 degrees per minute
- 2 minutes for 360 degrees
21
Q
Formula for working out angle of bank?
A
Take the last digit of TAS and adding 7
E.g.
Flying at 120kts TAS:
- Take out 0 and add 7
12+7 = 19
22
Q
Max rate turn
A
- Centripetal force must be maximum
- High AoB
- Increase AoA to critical angle
- Increase IAS
- An increase in speed steepens the AoB
- Max rate creates a lot of drag - full power is used
23
Q
Effect of wind during a constant-bank turn
A
- Wind pushes aircraft
- Pilot is still following a circle shape path, but is now moving with the airmass
24
Q
Constant-radius turn around a ground feature
A
- AoB must be adjusted
- As ground speed increases (in downwind part of turn), AoB must be increased
- When ground speed decreases (upwind) the AoB must be decreased.
25
Effect on the turning rate of climb/descend
- Dependent on excess power available
- Requires more power to overcome the increase in drag
- Reduces the excess power available - lowering rate of climb
26
Tendency to overbank/underbank in a climbing turn
- Outer wing has higher AoA
- Both wings gain the same height, the outer wing travels through a greater distance
- To maintain the AoB during a climbing turn, the controls must be kept slightly out of the turn
- During a climbing turn, the aircraft tends to over bank
27
Tendency to overbank/underbank in a descending turn
- Outer wing has a smaller AoA
- During a descending turn, the aircraft has a tendency to underbank
- Pilot is required to hold enough control into the turn
28
Vertical loop
- Centripetal force needs to remain constant along the entire loop
- Centripetal forces acts in line with the lift
29
What happens when the AoA is increased pass the critical angle?
- Airflow can no longer maintain adherence
- Separation point moves swiftly forwards and the CoP moves rapidly aft.
30
Basic stall speed
Used because we don’t have an AoA indicator
31
For a given configuration the surface area and camber of the wing…
Remains constant
32
Symptoms of the approach of a stall
- Noise - reduction
- Airspeed - low and decreasing
- Nose attitude - progressively getting higher
- Control effectiveness - not as effective due to lack of airflow and slipstream
33
Warnings of a stall
- Stall warning
- Buffet
34
Standard stall recovery
SPRACC
Stick - down
Power - full
Rudder - control yaw
Aileron - centralise
Centralise - rudder
Climb
35
Aircraft weight and stall speed
- Increased weight = increased stall speed
36
New stall speed formula
Basic stall speed (of old weight) x root(new weight/old weight)
37
Load factor and stall speed
- Increase in load factor = increased in stall speed
Load factor = lift/weight
38
Power on stall speed
- The stall speed with power is slower than the one with no power.
39
Altitude on stall speed
- Indicated stall speed is going to be the same
40
Use of flaps/slats on stall speed
- Flaps augment the camber of the ing
- Coefficient of lift will be greater
- Using flaps reduces the stall speed
- Using slats reduces the stall speed
41
Wing surface contamination on stall speed
- Contamination reduces the coefficient of lift
- Increases the stall speed
42
Wing drop stall
- One wing stalls before the other
43
Unbalanced flight
- Induces slip or skid
- Shelters a wing from the relative airflow with the fuselage
- Unbalanced rudder movement induces one wing to travel slower than the other one
44
Use of aileron near the stall
- Further develops the stall
45
Climbing and descending turns and wing drop stall
- Due to difference in AoA
- One wing can stall before the other
46
Wing contamination and wing drop stalls
- If one is more contaminated than the other
- One will wing drop faster
47
Reducing the tendency to wing drop
- Stall strips - on the leading edge inboard section of the wing. Disrupt the boundary layer at high AoA. Causes inboard portion of the wing to stall first, enhancing stability during a stall and preserving airflow over the ailerons
- Washout - variance in angle of incidence between the wing root and tip. The wing root reaches its stall point before the wingtip, promoting a more controlled and gradual stall onset
48
Wing drop recovery
SPRACC
49
Process of autorotation
- Happens if no action is taken to recover from a wingdrop
50
Characteristics of a spin
- Yaw in one direction around a vertical axis
- If the Cog is forward, the nose attitude will pre low
- If the CoG is past the aft limit, the spin will be flat and it might be impossible to recover as the elevator won’t have enough force to pitch the nose down
51
Instrument indications of a spin
In a stabilised spin:
- airspeed indicator shows a slow and fluctuation airspeed
- turn coordinator shows a turn in the direction of the spin
52
Spin recovery technique
PARE
Power - close throttle
Aileron - centralise controls
Rudder - full opposite rudder
Elevator - ease forward
