CPL Practice Exam 8

In aeronautics, the aspect ratio of a wing is the ratio of its span to its mean chord So for example, a wing that’s long and skinny has a high aspect ratio, and a wing that’s short and stubby has a low aspect ratio.

High aspect ratio wings have one major advantage: because the wingtip has less area, there is less vortex-induced downwash, which means a lot less induced drag..

PITOT TUBE BLOCKAGE

A pitot tube blockage can be caused by dirt, moisture, ice or even bugs. And, of course, aborted takeoffs after a failure to note “airspeed alive” on the takeoff roll, only to later find the pitot-tube cover still on, almost mockingly. Assuming a proper preflight inspection, ensuring the pitot tube is free and clear, obstructions can still unfortunately occur during flight. There are a few possible scenarios.

Blocked pitot tube with unblocked drain hole: This would result in the airspeed indicator reading zero. Because the pitot tube would not be able to sense any airflow, and the drain hole would let any residual air out, there would be no pressure differential for the airspeed indicator to measure.

Blocked pitot tube with blocked drain hole: With trapped dynamic pressure, the airspeed will indicate whatever speed was showing when the blockages occurred. If the aircraft’s static port remains unblocked, pressure will increase as the aircraft descends and decrease as the aircraft climbs.

If static pressure decreases during a climb, the trapped ambient pressure with allow the diaphragm to expand, showing an increase in airspeed. Conversely, descending into denser air will force the diaphragm to close, showing a decrease in airspeed. In short, the airspeed will act in a manner similar to an altimeter.

STATIC PORT BLOCKAGE

Blockages of the static port will affect all pitot/static instruments.

Airspeed Indicator: If the static port is blocked but the pitot tube remains clear, the ASI will function but not with accuracy. If speed remains constant, and the aircraft climbs or descends, the static pressure will result in changes to your airspeed indication. It’s the same principle as a blocked pitot tube but reversed.

A climb will result in a decrease in atmospheric pressure entering the pitot tube, which will result in the ASI indicating decreasing airspeed, causing the ASI to act as a “reverse altimeter.” As long as the pitot tube is not blocked, changes in airspeed will reflect on the ASI, but not accurately.

Vertical Speed Indicator: With no changes to static air, there can be no differential pressure for the VSI to work with. With no differential pressure, the VSI will be stuck at zero, and you’ll marvel at how well you’re maintaining altitude.

Altimeter: The altimeter will freeze at whatever altitude was indicated when the static port was blocked.

Dihedral is the upward angle of an aircraft’s wings.
It helps improve lateral stability.
This is a roll movement along the longitudinal axis.

The upper wing stalls first causing the wing to drop and spin to the left.

A normally aspirated, propeller-driven aircraft can achieve maximum range by flying at the altitude where it achieves its best lift-to-drag ratio (L/D ratio). This altitude is typically known as the “best L/D altitude.” At this altitude, the aircraft experiences the least drag relative to the amount of lift it produces, allowing it to travel the farthest distance for a given amount of fuel.

The horn balance, which is forward of the hinge line, generates a downward force generating a clockwise moment that opposes the control force. This reduces the effort the pilot must put in to control the aircraft.

From the Ground UP – Balanced Controls

Controls are sometimes dynamically balanced to assist the pilot to move them. By having some of the control surface in front of the hinge, the air striking the forward portion helps to move the control surface in the required direction. The design also helps to counteract adverse yaw when used in aileron design

As carburetor heat is applied, the manifold pressure will decrease and the mixture enriches initially. This occurs because the hot air entering the carburetor is less dense than the cold air, leading to a richer fuel-air mixture. As the ice melts and clears, engine power should gradually return to normal, and engine smoothness should improve.

Wing and Ball at the same direction: Slipping turn

Wing and Ball different directions: Skidding turn

Wing either to the right or left and ball centered: coordinated turn

Carb heat introduces hot air to your carb, instead of the cold air normally drawn through the air filter. Hot air is less dense, so there is less mass of air in each cylinder cycle. The mass of fuel remains the same. So, since there is more mass of fuel per mass of air, adding carb heat richens the mixture.

As carburetor heat is applied, the manifold pressure will decrease and the mixture enriches initially. This occurs because the hot air entering the carburetor is less dense than the cold air, leading to a richer fuel-air mixture. As the ice melts and clears, engine power should gradually return to normal, and engine smoothness should improve.

AIM AIR 1.6.6

Reference: AIM AGA 7.6.4.3

Load factors in a turn:

0º = 1g
15º = 1.04g
30º = 1.15g
45º = 1.41g
60º = 2.0g

Load factor formula:

Stall speed in a turn: √(load factor) * stall speed in the clean config

The land factor for a 60 deg bank is 2 g’s

The share root of 2 is 1.41

1.41 x the stall speed (Vs – clean config) 48 knots

= 67 knots.

Stall speed in the landing config formula

1.3 x Vso= landing speed.

1.3 x 36 = 47 kCAS

In practical applications, remember to convert the answer from CAS into IAS using the  tables in POH.

Forward CG

1. Higher stall speed
2. More nose up attitude
3. More stable
4. Less fuel efficient (more drag)
5. Good stall recovery characteristics

Rearward CG

1. Less Stable
2. Require less trim
3. More fuel efficient (less drag)
4. Lower stall speed
5. Bad stall recovery characteristics

Forward CG

1. Higher stall speed
2. More nose up attitude
3. More stable
4. Less fuel efficient (more drag)
5. Good stall recovery characteristics

Rearward CG

1. Less Stable
2. Require less trim
3. More fuel efficient (less drag)
4. Lower stall speed
5. Bad stall recovery characteristics

What is Maneuvering Speed?

Maneuvering speed, or V_a, is an airspeed published by your aircraft’s manufacturer that guarantees that your aircraft will stall before you reach the maximum certified g-load.

Aircraft V_a is certified with the assumption of the movement of a single flight control surface, in a single direction, in smooth air.

The essential concept behind V_a protection is that, assuming you are at or below your V_a your aircraft will stall as you reach its’ maximum structural load (g-limit). As your plane stalls, it unloads the g’s, eliminating the risk of bending metal.

Relationship Of Weight And Maneuvering Speed

When your aircraft is certified, its maneuvering speed is determined at maximum gross weight. As your aircraft gets lighter, your maneuvering speed gets slower. This is the confusing part of maneuvering speed, but it doesn’t have to be.

Increased Weight → Increases AOA → Increases V_a

Aircraft weight affects the Angle of Attack (AOA) you fly at to maintain level flight. While a lower weight might only require one or two degrees of nose-up pitch to maintain level flight, a heavier aircraft might require a few more degrees of pitch up to stay level, assuming the aircraft’s speed and configuration remain the same.

This is because, at the same speed and configuration, a heavier aircraft needs to fly at a higher angle of attack to produce enough lift to counter the aircraft’s weight in level flight.

It’s all about degrees. Your wing will always stall at the same AOA, with most general aviation planes stalling somewhere between 16 to 20 degrees of angle of attack.

With a heavier aircraft, your AOA in cruise is closer to the critical AOA, causing you to stall at a faster airspeed. A lighter aircraft will have more degrees of AOA to increase before it encounters the critical AOA, causing you to stall at a lower airspeed.

Fixed Pitch Prop:

On a fixed pitch prop, when the blade angle increases, it takes a bigger bite out of the air. Therefore, the RPMs will decrease.

Constant Speed Prop:

On a constant speed prop, as the name suggest, it maintains a constant RPM speed with the changing blade angles.

How a Constant Speed Propeller Works

Modern constant speed propellers work by automatically adjusting their pitch hydraulically, using a propeller governor or constant speed units and pressurized oil pumped through the propeller shaft. The pilot adjusts the pitch or propeller blade angle of a constant speed prop by moving the propeller lever.

SPEEDER SPRING

When the pilot moves the prop lever, the attached governor control lever and threaded shaft move as well. As the shaft moves, it either applies or releases pressure on the speeder spring.

Pulling back on the lever increases the pitch of the blades as well as the corresponding torque requirement needed to hold a constant engine RPM.

In the absence of increased power, both the engine RPM and the prop speed will slow. This is the high pitch/low PRM propeller blade configuration, and it is generally used once you have reached your cruising altitude.

If the prop lever is pushed forward, blade pitch decreases, along with torque requirements needed for constant RPM. Keep power the same, and the engine RPM will increase. This configuration is a low pitch/high RPM set-up that is used for takeoff.

A constant speed prop keeps a constant RPM with the aircraft’s chancing pitch attitude.

Basically, there are 2 types of constant speed props. One that relies on counterweights and the other that is hydromatic.

During an engine failure, therefore loss of oil pressure.

1) With a counterweight constant speed prop
If oil pressure is lost during flight, the propeller will automatically go into a full coarse pitch position where the blades stop turning and are streamlined with the airflow to reduce drag. This is used on twin engine aircraft.

2) With a hydromatic constant speed prop
If oil pressure is lost during flight, the propeller will automatically go into full fine pitch, enabling the engine to develop the most power that it can and to achieve the best performance under the circumstances. This type of propeller is used in single-engine aircraft.

AIM AIR 3.2.2 Carbon Monoxide

Carbon monoxide is a colourless, odourless, tasteless gas that is a product of incomplete combustion. Haemoglobin, the oxygen- carrying chemical in the blood, picks up carbon monoxide over 200 times more readily than it picks up oxygen. Thus, even minute quantities in the cockpit (often from improperly vented exhaust fumes) may result in pilot incapacitation.

The symptoms of carbon monoxide poisoning are insidious. Initially, there is an inability to concentrate, thinking becomes blurred, and subsequently dizziness and headache develop. If any of these symptoms are noticed, pilots should turn off the heater, open the air ventilators and descend to a lower altitude if it is safe to do so. If oxygen is available, it should be used. If an exhaust leak is suspected, the pilot should land the aircraft as soon as possible.

Smoking is a source of carbon monoxide. Smokers carry some carbon monoxide in their blood all the time, and may have 5 to 10 percent of their haemoglobin saturated with carbon monoxide. This reduces the oxygen-carrying capacity of the blood and smokers may become hypoxic at altitudes below 10 000 ft ASL (3 050 m).

Catalytic heaters consume oxygen and can produce carbon monoxide. For this reason they should not be used on an aircraft.

High to low, look out below; Low to high, too much Sky

1. Take the current altimeter setting and subtract is from the standard. Then times that by 1000 ft.
2. Then add the altitude for a higher pressure or subtract the altitude for a lower pressure.

Answer:

1. 29.92 – 30.12 = .20 inches x 1000 = 200 ft correction
2. 200 ft + 5000 = 5200 ft. We added the 200 ft because we flew to an area of higher pressure. We are flying at a true altitude of 5200 ft MSL.

The True Airspeed Rule of Thumb under standard conditions is 2% of CAS for every thousand Feet.

2% x 100 = 2

2 x 6 (using 6,000 ft) = 12%

12% added to 100 knots = 112 Knots TAS

Means any frost, ice, slush or snow that adheres to the critical surfaces of an aircraft.

Handbook for Civil aviation Medical Examiners

Hypoxia is an insidious killer. There is a tendency for euphoria to develop while motor skills and reasoning abilities deteriorate. The result is that in many cases the pilot may become seriously hypoxic without appreciating that there is a problem. To the observer tachypnea, cyanosis, mental confusion and loss of muscle coordination are obvious. To the pilot however, the only symptoms may be slight dyspnea, dizziness, fatigue, decreasing vision and finally loss of muscular control. Night vision can be impaired at as low as 5000 ft. Tolerance to hypoxia varies from individual to individual and from time to time. Tolerance can be increased by continual exposure to high altitudes and varies with the level of the hemoglobin and the oxygen carrying capacity of the blood. It is decreased by fatigue, cold and poor physical conditioning. Even at 5,000 ft. night vision is decreased.

Types

Hypoxia is generally divided into four types.

Hypoxic hypoxia is due to a decrease in the oxygen available to the body such as typically occurs with altitude.

Hypemic hypoxia is caused by a reduction in the oxygen carrying capacity of the blood for any reason. It also occurs when hemoglobin is saturated by gases for which it has a higher affinity, the most common of which is carbon monoxide. This is not only produced by exhaust leaks into the cockpit but also by cigarette smoking. Carbon monoxide is a product of incomplete combustion and may be present at levels of 6-8% in the blood of a heavy smoker and such individuals may become significantly hypoxic at levels below 10,000 ft.

Stagnant hypoxia is a less common problem caused by a reduction in total cardiac output, pooling of the blood or restriction of blood flow. Heart failure, shock, continuous positive pressure breathing and Gforces in flight can create stagnant hypoxia. Local stagnant hypoxia can occur with tight and restrictive clothing or, in the cerebral circulation, in association with vasoconstriction due to respiratory alkalosis provoked by hyperventilation.

Histotoxic hypoxia refers to poisoning of the respiratory cytochrome system by chemicals such as cyanide or carbon monoxide but it can also be caused by the effects of alcohol. Needless to say a pilot in poor physical condition, recovering from a hangover and smoking while in flight can quickly become an unfortunate statistic!

AIM AIR 3.2.2 Carbon Monoxide

Carbon monoxide is a colourless, odourless, tasteless gas that is a product of incomplete combustion. Haemoglobin, the oxygen- carrying chemical in the blood, picks up carbon monoxide over 200 times more readily than it picks up oxygen. Thus, even minute quantities in the cockpit (often from improperly vented exhaust fumes) may result in pilot incapacitation.

The symptoms of carbon monoxide poisoning are insidious. Initially, there is an inability to concentrate, thinking becomes blurred, and subsequently dizziness and headache develop. If any of these symptoms are noticed, pilots should turn off the heater, open the air ventilators and descend to a lower altitude if it is safe to do so. If oxygen is available, it should be used. If an exhaust leak is suspected, the pilot should land the aircraft as soon as possible.

Smoking is a source of carbon monoxide. Smokers carry some carbon monoxide in their blood all the time, and may have 5 to 10 percent of their haemoglobin saturated with carbon monoxide. This reduces the oxygen-carrying capacity of the blood and smokers may become hypoxic at altitudes below 10 000 ft ASL (3 050 m).

AIM AIR 3.9 ALCOHOL

Never fly while under the influence of alcohol. It is best to allow at least 24 hours between the last drink and take-off time. Alcohol is selectively concentrated by the body into certain areas and can remain in the fluid of the inner ear even after all traces of alcohol in the blood have disappeared. This accounts for the difficulty in balance that is experienced in a hangover. Even small amounts of alcohol (0.05 percent) have been shown in simulators to reduce piloting skills. The body metabolizes alcohol at a fixed rate and no amount of coffee, medication or oxygen will alter this rate. ALCOHOL AND FLYING DO NOT MIX.

If you find that you are drinking excessively or encountering problems related to alcohol, you must refrain from flying and seek assistance. Transport Canada has a policy and pathway to return to flying with the appropriate treatment and monitoring. Early intervention and active engagement are best for long-term success.

Alcohol or Drugs — Crew Members

602.03 No person shall act as a crew member of an aircraft

(a) within 12 hours after consuming an alcoholic beverage;

(b) while under the influence of alcohol; or

(c) while using any drug that impairs the person’s faculties to the extent that the safety of the aircraft or of persons on board the aircraft is endangered in any way.

AIM AIR 3.12 BLOOD DONATION

Aircraft Icing

602.11 (1) In this section, critical surfaces means the wings, control surfaces, rotors, propellers, horizontal stabilizers, vertical stabilizers or any other stabilizing surfaces of an aircraft, as well as any other surfaces identified as critical surfaces in the aircraft flight manual.

(2) No person shall conduct or attempt to conduct a take-off in an aircraft that has frost, ice or snow adhering to any of its critical surfaces.

(3) Despite subsection (2), a person may conduct a take-off in an aircraft that has frost caused by cold-soaked fuel adhering to the underside or upper side, or both, of its wings if the take-off is conducted in accordance with the aircraft manufacturer’s instructions for take-off under those conditions.

(4) Where conditions are such that frost, ice or snow may reasonably be expected to adhere to the aircraft, no person shall conduct or attempt to conduct a take-off in an aircraft unless

(a) for aircraft that are not operated under Subpart 5 of Part VII,

(i) the aircraft has been inspected immediately prior to take-off to determine whether any frost, ice or snow is adhering to any of its critical surfaces, or

(ii) the operator has established an aircraft inspection program in accordance with the Operating and Flight Rules Standards, and the dispatch and take-off of the aircraft are in accordance with that program; and

(b) for aircraft that are operated under Subpart 5 of Part VII, the operator has established an aircraft inspection program in accordance with the Operating and Flight Rules Standards, and the dispatch and take-off of the aircraft are in accordance with that program.

(5) The inspection referred to in subparagraph (4)(a)(i) shall be performed by

(a) the pilot-in-command;

(b) a flight crew member of the aircraft who is designated by the pilot-in-command; or

(c) a person, other than a person referred to in paragraph (a) or (b), who

(i) is designated by the operator of the aircraft, and

(ii) has successfully completed training relating to ground and airborne icing operations under Subpart 4 or relating to aircraft surface contamination under Part VII.

(6) Where, before commencing take-off, a crew member of an aircraft observes that there is frost, ice or snow adhering to the wings of the aircraft, the crew member shall immediately report that observation to the pilot-in-command, and the pilot-in-command or a flight crew member designated by the pilot-in-command shall inspect the wings of the aircraft before take-off.

(7) Before an aircraft is de-iced or anti-iced, the pilot-in-command of the aircraft shall ensure that the crew members and passengers are informed of the decision to do so.

AIM AIR