Checkride

How can you stall during a turn?

When you turn, the aileron of the outside wing is deflected downward, while the inside wing’s aileron is deflected upward. Also, the down aileron generates a higher AOA than the up aileron. Thus, you can stall in a turn because of the difference in AOA between the wings. The outside wing/down aileron is at a higher AOA and is closer to exceeding the critical AOA.

More lift continues to be developed by the down aileron wing, which pushes it higher and increases its chances of hitting the critical AOA.

How does a stall occur?

When the wing exceeds the critical angle of attack and the airfoil can no longer support lift due to the turbulent airflow over the airfoil’s surface

What is an accelerated stall and when can it occur?

An accelerated stall is an example of how a stall can occur at any airspeed. These types of stalls primarily occur in turns. The aerodynamics behind this are based around the fact that in straight and level flight, you have an upwards lift vector and a downwards weight vector. When you are in a turn, your lift vector now does not point directly upwards and instead is both upwards AND at an angle. Despite having two vectors, you are producing less lift overall. So, if the pilot wants to maintain the same altitude while in a turn, they must pitch up to compensate for this loss of lift in a turn. However, there is only so much more you can increase your angle of attack before you stall.

Additionally, an aircraft in a turn will experience an increase in load factor. This is because load factor is a ratio between lift and weight,

What is a cross controlled stall and when can it occur?

A cross controlled stall occurs when the critical angle of attack is exceeded with opposite rudder and aileron pressure. This is most likely to occur during a skidding turn from your downwind to base or base to final turns, if you realize you are overshooting the runway. Your reaction may be to increase your turn rate by decreasing bank and stepping on the rudder, while simultaneously keeping aft elevator to maintain your altitude for the traffic pattern.

What are the types of a spin?

Erect: roll and yaw in the same direction

Inverted: roll and yaw in the opposite directions; the aircraft is upside down

Flat: yaw only

• Very dangerous and difficult to get out of

What is the difference between an intentional and unintentional slip?

An intentional slip is a method of increasing the rate of descent without increasing airspeed.

An unintentional slip is caused by insufficient rudder input

What is the difference between a slip and a skid?

Slip: when the aircraft moves sideways and forward because there is not enough rudder input

Skid: the aircraft is moving towards the outside of a turn because there is too much rudder

What is the danger with stalling between a slip or a skid?

In a slip, the upper wing will stall first simply because it is at a higher angle of attack. When the stall occurs, the upper wing will drop and the aircraft will enter level flight.

In a skid, the inner wing will stall first because it is experiencing no relative wind, so if the pilot tries to raise the inner wing, it will feel as if it is immensely exceeding the critical AOA and immediately stall. This is a danger because the lower wing will drop when it stalls, thus creating the potential for the aircraft to roll into a spin.

What is ground effect?

When an aircraft is in flight, it creates wingtip vortices as a result of high pressure on the underside of the wing and low pressure on the top (air always wants to flow from a high to a low). When you get close to the ground, wingtip vortices can’t get as big, because they spin around your wingtip, impact the ground, and dissipate. This causes a decrease in downwash, which is the backwards spiral of these vortices. Because of this, you have less induced drag, so you begin to float upon getting closer to the ground

What is the procedure for a forward slip? What is the point of employing one?

A forward slip increases your angle of descent without increasing your airspeed by subjecting the airplane to a lot of drag by subjecting the side of the fuselage to the relative wind, something that is not aerodynamically efficient.

Procedure: (when high upon final approach)

• Idle power

• Full flaps

• Right rudder, left aileron

• Forward elevator (your airspeed is controlled by your pitch!)

What is the difference between a forward slip and a sideslip?

Forward slip: descends without increasing airspeed

Sideslip: maintains runways alignment in crosswind landings

Name some key points about center of gravity on an airplane.

• Airplanes are designed so they are slightly nose heavy, as this helps return the aircraft to normal flight if disturbed (by reducing the chances that a stall could occur)

• Loading an aircraft with an aft CG

  • Decreased longitudinal stability

  • Decreased control efficiency

  • Bad stall recovery

  • Fuel efficient (elevator does less work to keep the aircraft balanced)

• Loading an aircraft with an forward CG

  • Increased longitudinal stability

  • Good stall recovery (nose goes down)

  • Fuel inefficient (all control surfaces are doing more work to ensure the aircraft stays level; more back elevator, etc.)

What is the purpose of dihedral?

It helps stabilize an aircraft in a spiral because it rolls the wings back to level flight.

• How it achieves this: there is an inherent increased AOA on the low wing in a turn, which increases lift on that wing and rolls it back to level

ESTABLISHES LATERAL/ROLL STABILITY

What are the four left turning tendencies and how are they created?

1. Torque

   • At low airspeeds and high power, the aircraft experiences a yaw to the left due to the direction of rotation of the propellor

2. Spiraling slipstream

   • The wash from the propellor spirals around the fuselage and strikes the left side of the empennage, forcing the empennage right and yawing the plane to the left

3. Gyroscopic precession

   • The principle of gyroscopic precession says that a spinning object feeling a force will experience it 90 degrees from where the force is applied. This is relevant to left turning tendencies because the propellor spins

4. P-factor

   • The descending blade of a propellor produces more thrust than the ascending blade, and since propellors rotate in a clockwise fashion, as viewed from the cockpit, the descending blade on the right is producing more thrust, thus yawing the aircraft to the left (t-shaped arms push concept)

What is adverse yaw and why is it important? How do you counteract it?

When turning, aircraft yaw towards the outside of the turn because the outside wing is experiencing more lift (AKA the aircraft yaws in the direction opposite the turn). The outside wing experiences more lift because the aileron is deflected downwards, thus altering wing camber in a way that is conducive to generating lift.

You can counteract adverse yaw by using more control inputs in the direction of the turn, since your aircraft is trying to yaw out of it.

What are the types of drag?

Parasite drag

(caused by any surface that interferes with airflow)

• Form drag

  • The shape of a structure can cause separation of airflow from the surface

• Interference drag

  • Drag generated at connection points on the aircraft, such as where the wing is joined with the fuselage

• Skin friction

  • Roughness of the aircraft’s surface that interferes with the smooth flow of air

Induced drag

• A product of lift

Total drag

• Total = parasite + induced

What is the maneuvering speed? What is it for the PA-38?

Maneuvering speed is the speed at which you will stall before you cause structural damage if you deflect a single flight control, in one direction, in smooth air

For the Tomahawk, this is 103 kts. This is also placarded in the aircraft

How are speed and lift related?

Bernoulli’s principle states that faster moving air has lower pressure than slower moving air. So, as the speed of an aircraft increases, the faster moving air on the top of the wing experiences even lower pressure than before, thus increasing the lift of the aircraft

What is needed for a thunderstorm to form?

C limb (lifting action)

U nstable atmosphere

M oisture

How does frost form?

If the temperature of a collecting surface is below the dewpoint of the surrounding air, and the dewpoint is colder than freezing

What is rime ice? Where is it formed? Why is it significant?

Rime ice is formed when supercooled water droplets freeze upon impact onto a surface. It is opaque, milky, rough, and granular.

It is formed when flying through filmy/stratiform clouds

It is significant because it disrupts airflow over the wings, increases drag, and adds weight

What is fog? What circumstances are required for it to form?

Fog is the weather phenomenon occurring when visibility is less than 1 km

There must be moist, stable air in the atmosphere. The air must cool to the dewpoint, which is the temperature at which the air can no longer hold water vapor and must hold water droplets

What are the types of fog and how do they form?

Radiation

• During the day, the sun heats the ground

• At night, once the sun is below the horizon, the heat from the ground radiates upwards

• This leaves the air near the ground very cool, and since there is moisture in the atmosphere, fog can form if the air becomes cool enough to drop to the dewpoint

Advection (uses wind)

• During the day, the sun heats the ground faster than it heats the adjacent water

• At night, once the sun is below the horizon, the heat from the ground radiates upwards faster than heat escapes from water.

• Wind pushes the warmer, moister air from above the water over the cooler, drier land, where the moist air becomes cooled to the dewpoint and fog forms

Upslope (uses wind)

• Warmer, moister air from the bottom of a mountain rises (due to wind) and is cooled to its dewpoint on the top of the mountain

Steam

• Cold air moves over warm, moist air, and the cold air cools it to its dewpoint and fog forms

Precipitation induced

• Moisture is added to the air from precipitation, and can create fog if the temperature and dewpoint conditions are conducive to it

What are the atmosphere’s lapse rates?

The rate at which air temperature and dewpoint cools with increasing altitude

Temperature: 2 degrees C per 1000 ft

Dewpoint: 0.5 decrees C per 1000 ft

What is relative humidity and why is it important in understanding the atmosphere?

Relative humidity is the measure of the actual amount of water vapor currently in the air, as compared to the total amount of vapor that could exist at its current temperature

What is dewpoint? Why is it important enough to include in the ATIS?

Dewpoint is the temperature at which air reaches 100% relative humidity

The reason it is so relevant for aviation is because if there is a small difference between temperature and dewpoint, there is high humidity and a greater risk of low visibility conditions like fog. Since you are given both the temperature and dewpoint, you are more informed about current and predicted future weather conditions

At what temperature/dew point spread should you expect fog?

If the temperature/dew point spread is less than 3 degrees celsius

What are clouds?

Clouds are made up of tiny water droplets or ice

Droplets condense onto condensation nuclei, which can be dust, sea spray, etc

How do you find cloud bases?

Temperature dewpoint spread / 4.4 F

OR

temperature dewpoint spread / 2.5 C

then multiply by 100

What are the types of AIRMETs? How long are they in effect for?

Sierra

• Visibility less than 3 SM

• Ceilings less than 1000 ft

Tango

• Sustained surface winds greater than 30 kts

• Moderate turbulence

Zulu

• Freezing

• Moderate icing

AIRMETs are in effect for six hours

What sort of weather is included in a SIGMET? How long is it valid for?

S andstorm

I cing (severe)

G reather than 3000 mi²

M iserable visibility (from volcanic ash, etc)

E xpires in six hours

T urbulence

What sot of weather is included in a convective SIGMET? How long is it valid for?

CONVECTIVE activity!

• Winds greater than 50 kts

• Hail greater than ¾ inch in diameter

• Embedded thunderstorms (40% area of at least 3000 mi²)

• Tornadoes

• Severe icing

Valid for 4 hours!

What will happen to your altimeter as you fly from a higher pressure to a lower pressure?

Your altimeter will indicate a higher pressure (hence why you have to “look out below”— because you’re on top of everyone). This is because ______________

What is the definition of the cruise region? What is the range for the PA-38?

The cruise region is the speed range where the airplane’s airspeed can be accelerated or decelerated without requiring a patch change to maintain altitude.

For the Tomahawk, it is 80-100 kts

What is the flap region? What is this range for the PA-38?

The flap region is where the pilot can operate with flaps down without having to pitch up to maintain altitude.

For the Tomahawk, this is 70-80 kts

What is the slow flight region? What is the range for the PA-38?

The slow flight region begins at the speed where any reduction of airspeed in LEVEL flight requires an INCREASE in the aircraft pitch attitude in order to maintain altitude.

For the Tomahawk, this is 65-80 kts

What is the stall region? What is this range for the PA-38?

The stall region is the area BELOW safe flight speed in which any further reduction in airspeed may result in a stall.

For the Tomahawk, this is 47-55 kts

What does flying from a higher to a lower pressure region indicate? Why?

It will indicate that you are at a higher than true altitude. This is because the altimeter is sensing a decrease in atmospheric pressure, thus thinking you are higher.

What does flying from a lower to a higher pressure region indicate? Why?

It will indicate that you are at a lower than true altitude. This is because the altimeter is sensing an increase in atmospheric pressure, thus thinking you are at a lower altitude than you actually are

What are some characteristics of a high pressure system?

Clockwise rotating air

Colder temperatures

• Think of it like molecules are cold and need to compress to get warm

• Also because colder temperatures have higher pressures just on principle

What are some characteristics of a low pressure system?

Counterclockwise rotating air

Warm temperatures

Why are there variations of pressure around the planet?

The tilt of the earth causes different areas to be heated unequally, and the temperature influences the pressure

What are the three main wind cells? What direction to they rotate, and are they ascending or descending?

Polar cells rotate counterclockwise and descend.

Ferrel cells rotate clockwise and ascend

Hadley cells rotate counterclockwise and descend

Why are you given the temperature and dewpoint in the ATIS? Why is it important enough to be included?

If you know the temperature and the dewpoint, you can find the temperature dewpoint spread, which you can then use to calculate cloud bases if you divide the temperature dewpoint spread by 2.5 C and multiply by 1000

What are some rules regarding the ELT?

They must be replaced once half their useful battery is gone, or after one hour of cumulative use.

They must be inspected every 12 months

What are some differences between the annual and 100 hour inspection?

All aircraft must undergo an annual inspection

Aircraft for hire must also undergo 100 hour inspection

Annual inspection is more in depth and requires a more certified mechanic. It requires an A&P mechanic with an IA license (inspection authorization). However, the 100 hour mechanic doesn’t need to also have the IA.

Annual inspection can take place of a 100 hour inspection, 100 hour inspection can not take place of an annual

Does aircraft registration expire?

Yes, every 7 years

What is a special flight permit?

It gives a temporary flight permit to an aircraft that would otherwise not be airworthy. You could obtain one if the aircraft could still be flown and you are going to see a mechanic

How long are TAFs valid for?

24 hours, but issued four times every day

Why would a pilot issue a PIREP? (what circumstances)

In case of turbulence, visibility, or icing that are hazardous enough to where they feel they should warn other pilots about it

What are prognostic charts?

Contain information such as temperature, wind, precipitation, and fronts

Issued 4 times daily

Provides 12 hour and 24 hour forecasts

What are the differences between AIRMETs, SIGMETs, and convective SIGMETs?

AIRMET

• Weather conditions that may be hazardous to some aircraft, but not all

• For example, 2SM visibility is dangerous/illegal for VFR aircraft, but not for IFR

SIGMET

• Contain conditions like poor visibility from a large occurrence (volcanic ash, dust storm), severe icing, turbulence

• Hazardous conditions for all aircraft

CONVECTIVE SIGMET

• Convective conditions

• Thunderstorms, tornadoes, embedded thunderstorms, widespread

What is a ceiling?

The lowest broken or overcast layer of clouds

What is relative wind?

Air that your plane hits as you move through the air. It is always opposite to the direction of flight

What is a minimum equipment list?

It is the list of equipment that can be inoperative without grounding the airplane

If your radio fails in flight, what regulations must you follow to land at an airport in Class G, E, or D airspace?

If the aircraft radio fails in flight under CFR. the pilot in command may land if:

1. Weather conditions are at or above basic weather minimums

2. Visual contact with the tower is maintained

3. A clearance to land is recieved

What is UNICOM and when would you use it? What sort of information is exchanged?

UNICOM used to be used to provide airport advisories, but is now used to call an FBO directly an ask for services. If an airport doesn’t have a separate UNICOM frequency, there may be a MULTICOM frequency. If an airport doesn’t have either, it is used as the CTAF

At non-towered airports or when a control tower is not active to allow for pilot/pilot AND pilot/ground communication

Information you could exchange

• Announce taxiing, takeoff, landing

• Announce position, altitude, and intentions

• Talk to an FBO to request fuel, ground transport

Since the frequencies are usually the same, it is more who you are intending to talk to when you call on the frequency:

• You call "Traffic" on the CTAF when you are self reporting your position. You are not soliciting of expecting a response. You are talking to other aircraft.

  You call "Unicom" when you are expecting a response from someone at a ground station.

What is the PA-38’s design maneuvering speed (Va)?

Do not make full or abrupt control movements above this speed

103 kts

What is the PA-38’s never exceed speed (Vne)?

Do not exceed this speed in any operation

138 kts

What is the PA-38’s maximum structural cruising speed (Vno)?

Do not exceed this speed except in smooth air and then only with caution

110 kts

What is the PA-38’s maximum flaps extended sped (Vfe)?

Do not exceed this speed with the flaps extended

89 kts