Stall, Mach Tuck upset Prevention And Recovery

Question 1

An aeroplane is flying in steady, straight and level flight at its 1g stall speed. If the pilot intends to turn left using ailerons, the aeroplane will….

Answer 1

Bank to the right, because the wind with the down going aileron will exceed the critical angle of attack

Question 2

An aircraft has a mass of 304 tonnes which includes 75 tonnes of fuel at take off. The aircraft lands with 8.5 tonnes of fuel remaining. On take off, its stalling speed was 100 kt. Determine the stalling speed on landing:

Answer 2

88.4 kt

(The aircraft has burnt 75-8.5= 66.5 tonnes of fuel. Landing mass = 304-66.6 = 237.5 tonnes.

New Vs = Old Vs √change in mass
New Vs = 100 √(237.5/304)
New Vs = 88.4 kt

Question 3

During a deep stall of aeroplanes equipped with a swept-back and T-tail stabiliser, what happens to the elevator ?

Answer 3

Lies completely in the airflow behind the stalled wing and reduces the effectiveness of the elevators to decrease the angle of attack

Question 4

Regarding deep stall characteristics, identify weather the following statement are correct or incorrect

1) the combination of a wing with a sweepback and a T-tail make an aeroplane prone to deep stall

2) A stick pusher system can be fitted to an aeroplane that exhibits abnormal stall characteristics

Answer 4

1) correct

2) correct

Question 5

You notice ice on the tail plane and, as a result, the tail plane stalls stalls in the landing flare. How can you expect the aeroplane to behave ?

Answer 5

Nose goes down and nose wheel touches ground first

Question 6

The wing of an aeroplane will never stall at low subsonic speeds as long as…

Answer 6

The angle of attack is smaller than the value at which the stall occurs

Question 7

The pitch up tendency of an aeroplane with swept back wings during a stall is caused by:

Answer 7

Forward movement of the centre of pressure

Question 8

How do you get out of a spin ?

Answer 8

Power idle
Ailerons neutral
Rudder opposite
Push yoke

Question 9

An aircraft with a far aft CG location enters a spin, which becomes fully developed. What would the aircraft attitude likely be in this scenario

Answer 9

Nose level

(The more aft the CG, the flatter the spin attitude)

Question 10

Behind the transition point in a boundary layer what happens to mean speed and and friction drag?

Answer 10

The mean speed and friction drag increase.

Question 11

What are the two types of boundary layer ?

Answer 11

The laminar and turbulent boundary layers

Question 12

What is a boundary layer ?

Answer 12

A layer of fluid (the atmosphere) in the immediate surface of a bounding surface (the aerofoil) where the effects of viscosity are significant.

Question 13

What is the transition point in regards to laminar and turbulent flow ?

Answer 13

At a distance from the leading edge of the aerofoil, the air transitions from laminar flow to turbulent flow.

Question 14

Compared to a turbulent boundary layer, a laminar boundary layer… ?

Answer 14

Generates less skin friction drag

Question 15

The main problem of a boundary-layer fence on a swept wing is to…?

Answer 15

Improve the low speed handling characteristics

Question 16

The maximum cruise altitude can be limited by a 1.3G load factor because when exceeding that altitude…?

Answer 16

Turbulence may induce high speed or low speed buffet

Question 17

In order to reduce friction drag, some wings are designed so that, compared to a conventional aerofoil…?

Answer 17

The transition point is further aft to have more area with laminar flow

Question 18

An airplane has a 60kt stall speed. A pilot is flying at 90kt and then banks sharply to avoid other traffic and stalls the aircraft. Why has the aircraft stalled ?

Answer 18

Because the wing has exceeded its critical angle of attack and will stall regardless of airspeed

Question 19

The pilot of an aeroplane with a single engine and right turning propeller (clockwise from the pilots viewpoint) decides to go around. The pilot raises the nose too much as the power increases and stalls the aircraft. Most probably, the aircraft will…

Answer 19

Enter an incipient spin to the left due to toll and yaw caused by the propeller

Question 20

A pilot is testing the slow flight characteristics of an aeroplane with tapered (non swept) wings. What could they expect to experience approaching the stall

Answer 20

A light buffet on the ailerons

Question 21

A student pilot is flying a spinning exercise. Included in the recovery actions from an incipient spin is rudder…?

Answer 21

Rudder deflection in the opposite direction to the yaw, with reference to the turn needle

Question 22

One important advantage a turbulent boundary layer has over a laminar layer is that the turbulent boundary layer has less..

Answer 22

Tendency to separate from the surface

Question 23

For a conventional aeroplane with the aerodynamic centre behind the aeroplane’s COG, the presence of significant ice on the leading edge of the tail plane can cause the tail plane to stall. This could cause an uncontrollable pitch…

Answer 23

Down, and is more likely when the elevator is moved relatively up or when the wing flaps are extended

Question 24

You are the pilot flying of an aircraft currently over a holding fix and you observe that you are about to enter an area with heavy rain. How should you proactively respond to this situation ?

Answer 24

By increasing the holding speed and thrust to anticipate for the increased drag due to the film of water on the aeroplane

Question 25

You are the pilot flying a light aeroplane with a clockwise turning propeller. While you are distracted by having to deal with a minor equipment failure, the stall warning horn activates. What would indicate that the aircraft had entered a full stall, if you do NOT respond to the warning and try to maintain level flight using the elevator?

Answer 25

The nose pitching down with a full pitch up elevator

Question 26

Incipient spin is the term assigned to the phase of a spin:…

Answer 26

When the initial rotation starts but the aerodynamic forces present are not yet fully balanced

Question 27

What would warn of an imminent stall when flying close to Vs

Answer 27

Difficulty in maintaining altitude, loss of elevator effectiveness and/or low speed buffet

Question 28

A multi engined commercial jet with a underslung wing mounted engines is flying at the stall speed with idle power. If power is increased, CLMAX will (1)……. and the stall speed will (2)………

Answer 28

1) remain the same 2) decrease

Question 29

How does stall speed (IAS) vary with altitude ?

Answer 29

It remains constant at Lower altitudes but increases at higher altitudes due to compressibility effects.

Question 30

The boundary layer of a wing is….?

Answer 30

A layer on the wing in which the stream velocity is lower than the free stream velocity

Question 31

Vortilons that are attached to the underside of a wing…

Answer 31

Improve low speed handling characteristics

Question 32

The main purpose of a boundary-layer fence in a swept wing is to…

Answer 32

Prevent spanwise flow to prevent the wingtips from stalling first

Question 33

When a strongly swept-back wing stalls and the wake of the wind contacts the horizontal tail, the effect on the stall behaviour can be a

Answer 33

A nose up tendency and/or lack of elevator response

Question 34

In which phase of the take-off is the aerodynamic effect of ice located on the wing leading edge most critical

Answer 34

The rotation

Question 35

What does a stick pusher do ?

Answer 35

It pushes the elavator control forward when a specified value of angle of attack is exceeded

Question 36

An increase in wing loading factor will ?

Answer 36

Increase the stall speed

Question 37

On the base leg of a circuit to land, the pilot is distracted by the warning of an alternator failure, but elects to continue the approach, immediately turning onto final. During the final turn the pilot feels that the aircraft bank angle is difficult to maintain, that the ailerons and elevator are lighter and NOT as effective as usual. These symptoms are most likely related to…

Answer 37

A warning of an incipient stall

Question 38

Why would and aircraft in a coordinated turn during an approach suddenly stall ?

Answer 38

In a turn, the stall speed increases

Question 39

An inexperienced pilot inadvertently flies a light aircraft into a cloud, and due to lack of visual references allows the aircraft to enter a spiral dive. As the aircraft flies out of the cloud the pilot pulls hard on the control column to recover. The aircraft can still stall in this altitude due to the…

Answer 39

Wing exceeding the critical angle of attack

Question 40

What correctly describes wing fences?

Answer 40

Flat plates fixed to the upper surfaces parallel to the wing chord

Question 41

A pilot is flying an aeroplane whose clean configuration stall speed is 60kt. While cruising at 95kt the pilot has to take avoiding action against another aeroplane. The pilot banks the aeroplane sharply and during this manoeuvre, the aeroplane stalls. Why did the aeroplane stall at 95knots ?

Answer 41

A wing stalls when it’s critical angle of attack is exceeded, regardless of speed

Question 42

How is stall warning presented to the pilots of a large transport aeroplane ?

Answer 42

Stick shaker and/ or aerodynamic buffet

Question 43

What is correct about a fully developed spin ?

Answer 43

Speed is low and constant and spinning rate is constant

Question 44

An aeroplane where its CG is located forward of its centre of pressure suffers a premature tail plane stall as a result of ice contamination. Provided the wings do NOT stall, the outcome will be

Answer 44

Nose down pitch upset, the magnitude of which will depend on the location of the aeroplanes CG

Question 45

What happens to the stall speed in a steep turn ?

Answer 45

It increases because the vertical component of lift is reduced

Question 46

An aeroplane is established on final approach descending through 1000ft when the pilot realises that the aeroplane is about to enter an area of heavy tropical rain. The pilot must consider that the stalling

Answer 46

Speed increase due to the CL MAX reduction because of water distorting the shape of the airfoil and the airflow pattern

Question 47

When considering a swept-back wing, without corrective design features, at the stall what would happen… ?

Answer 47

Tip stall will occur first, which produces a nose up pitching moment

Question 48

Assuming the CG always remains within limits, how does the CG position relate to the spin attitude of an aeroplane regarding a flatter spin attitude…?

Answer 48

The further aft the CG, the flatter the spin attitude

Question 49

What could be an indication of a tail stall due to icing in regards to the elevator?

Answer 49

Elevator buffet

Question 50

The transition point is where the boundary layer changes from….?

Answer 50

Laminar into turbulent

Question 51

What sort of characteristics should a pilot expect from a swept-back wing when it begins to stall, and why ? The aeroplane will….

Answer 51

Pitch up, due to forward movement of the centre of pressure, caused by the wing tips stalling first.

Question 52

You are a the pilot flying of a light aircraft when, before turning though 360 degrees, you realise that you are in the incipient stage of a spin. To recover, the action must be:

Answer 52

Rudder opposite to the direction of the spin as indicated by the turn needle.

Question 53

A jet engine aeroplane is cruising close to its maximum altitude when it suffers an engine failure. While concentrating on completing the appropriate checklist, the pilots fail to notice the aeroplanes speed decreasing. The aeroplane develops buffeting, which eventually becomes strong enough to be considered a deterrent. This means that the aircraft is

Answer 53

Stalled

Question 54

What is the effect of icing or other airframe contaminants on the value of CL MAX, stall speed, and critical angle of attack? The CL MAX…. ??

Answer 54

Decreases, stall speed increases, and critical angle of attack decreases.

Question 55

In a steady, level, coordinated turn the load factor n and the stall speed Vs will be

Answer 55

n greater than 1, Vs higher than in straight and level flight

Question 56

The following factors increase stall speed:…

Answer 56

An increase in load factor, a forward CG movement, decrease in thrust

Question 57

Located on the underside of a wings leading edge, vortilons produce a vortex on the wings….

Answer 57

Upper surface, at high angles of attack, to reduce the spanwise flow of air

Question 58

What happens to the critical angle of attack with gross weight ?

Answer 58

Remains unchanged regardless of gross weight

Question 59

Which CG position contributes to flat spin ?

Answer 59

Aft CG

Question 60

A boundary layer fence on a swept wing will improve the…?

Answer 60

Low-speed stall characteristics

Question 61

What causes the deterrent buffet…?

Answer 61

High AOA

Question 62

What causes the deterrent buffet…?

Answer 62

High AOA

Question 63

What describes the standard spin recovery ?

Answer 63

Power to idle, ailerons neutral, opposite rudder, push controls forwards

Question 64

It is possible for the stabiliser to stall prematurely due to ice contamination. In this case the plane will….

Answer 64

Will pitch down

Question 65

An aeroplane is executing a missed approach after entering a microburst on the approach. The aeroplane may be very close to the stall due to the:

Answer 65

Increasing tail wing

Question 66

What should you do if you encounter a thunderstorm during your cruise that you cannot circumnavigate:

Answer 66

Fly at turbulence penetration speed

Question 67

An aeroplane is at risk of low speed stall under the following circumstances:

Answer 67

Climbing in “vertical speed” mode

Question 68

Which of these statements about the buffet free range in a buffet onset boundary graph are correct or incorrect ? 1)When speed increases the buffet free range does not change 2)when altitude decreases the buffet free range decreases

Answer 68

1) correct 2) incorrect

Question 69

An aircraft is very close to the stall due to increase in tailwind. What should the pilot’s first action be ?

Answer 69

Increase power before changing the pitch

Question 70

The pilot of a light aeroplane is flying at a speed below the normal cruising speed, in a gentle turn to allow a passenger to look at something interesting on the ground. What might occur to warn the pilots that the aircraft is approaching the stall?

Answer 70

The audible stall warning sounds. The controls become light and less effective close to but before the stall

Question 71

How does a plane with underslung engines increase the risk of a stall ?

Answer 71

With underslung engines, the use of the take off/ go around power settings (TOGA) produces powerful nose up pitching moments, increasing the risk of a stall.

Question 72

What are the first indications of a stall ?

Answer 72

Light buffeting before the stall Less control effectiveness

Question 73

Which of these statements about the buffet free range in a buffet onset boundary graph are correct or incorrect? 1) when speed increases the buffet free range decreases 2) when altitude decreases the buffet free range decreases

Answer 73

Incorrect Incorrect

Question 74

You are climbing to your aerodynamic ceiling in a busy class bravo airspace and you experience wind shear that increases the AOA, what will happen to your low speed Mach buffet.

Answer 74

Increases

Question 75

When does Mach buffet occur ?

Answer 75

Following boundary layer separation due to shock wave formation

Question 76

Which of the following may cause buffeting when flying through clear air turbulence ? 1. Mach, variations 2. Precipitation distorting the airflow 3. Reduced Mach margins at altitude 4. Autopilot disengagement

Answer 76

1 and 3

Question 77

An aircraft is flying near the ITCZ and suffers buffeting due to clear air turbulence ? What should be done ?

Answer 77

Descend to a lower altitude and fly at the turbulence speed

Question 78

Just after take off, a pilot inadvertently retracts his he flaps instead of the landing gear. What are the consequences ?

Answer 78

The aeroplane will stall if the speed is lower and Han the stall speed in clean configuration

Question 79

An aircraft climbs below the tropopause at a constant indicated airspeed. What would be the most likely cause for aircraft buffet ?

Answer 79

High much number due to increase in TAS

Question 80

Following a microburst encounter on approach, during the go around, what happens to speed control ?

Answer 80

Speed control has greater priority than reaching an optimised pitch angle.

Question 81

A jet transport aircraft flying at its cruising level starts a climb from FL350 to FL370. The climb to the new level is performed at a constant Mach number. What is the effect of the change in level on the buffet margin ?

Answer 81

The buffet margin will be smaller and the buffet will occur at a lower load factor

Question 82

In combination with an aural warning, what indicates in a light aircraft that it has entered a fully developed stall ?

Answer 82

Heavy buffeting felt through the flight controls

Question 83

If the pilot or a modern commercial large turbojet sets the vertical speed mode of the autopilot to carry out a climb. What must he be particularly careful of ?

Answer 83

If the climb is prolonged, there is a risk that the airspeed may reduce towards the stall

Question 84

A microburst encounter on the approach is a hazardous situation. When approaching the microburst the aeroplane will initially: ?

Answer 84

Encounter increasing headwind

Question 85

What is a possible cause for the auto recovery of an aeroplane after the stall ?

Answer 85

The angle of incidence of the wing is larger than the angle of incidence of the horizontal stabiliser

Question 86

You are descending and your altitude is decreasing. What is correct regarding your buffet margin is correct ?

Answer 86

The difference between M MIN and M MAX increases

Question 87

You are flying an approach and encounter wind shear. What might happen ?

Answer 87

A sudden extreme tailwind may make you stall

Question 88

A go around is performed by the crew of a commercial jet aircraft with under wing mounted engines and conventional controls. What will happen

Answer 88

Nose down elevator deflection must be applied in order to counteract the large thrust pitch up couple and to avoid a stall.

Question 89

You are on an approach when extending flaps, due to a malfunction the right flap does not extend. What will happen to the aircraft ?

Answer 89

Plane will bank right and right wing may stall

Question 90

A jet transport aircraft flying in the cruise climbs from FL360 to FL380. The climb to the new level is performed with a constant Mach number. What is the effect of the change in level on the buffet margin ?

Answer 90

The buffet margin will be smaller, and the buffet will occur at a lower load factor

Question 91

A large transport jet flying in a busy airspace is cleared to fly at close to its maximum altitude for its current inflight mass. At that altitude the aircraft encounters clear air turbulence, which increases the AOA for a short time with no change in airspeed or Mach number. What is the effect of the increase in AOA on the low speed buffet margin

Answer 91

It decreases

Question 92

The low speed and high speed buffet margins increase by

Answer 92

Reducing mass