Gotcha Flashcards
What is the true altitude VS. absolute altitude?
True altitude - the aircrafts height above mean sea level (MSL)
absolute altitude - the aircrafts height above the terrain (ground level) directly beneath it
What are the basic weather min for VFR flight according to 91.155?
Can we takeoff Golf airspace under 3 sm visibility?
What is cloud clearance for golf?
refer to 91.155
yes, you can fly with under 3 sm of visibility
clearance < 1,200’
day = 1sm CoC / night 3152
clearance > 1,200’ above surface > 10,000’ MSL - 5111
What does mixture actually do?
The mixture control regulates the ratio of fuel to air entering the engine.
-sea level, where air is dense, a rich mixture is used
-higher altitudes, the air becomes less dense, (less O2) lean mixture prevents excess fuel from being delivered to engine
a mixture too rich at higher altitudes can cause:
-spark plug fouling (due to unburned fuel)
- loss of power and increased fuel consumption
Why do we lean the mixture?
compensates for decreased air density:
as altitude increases, the air density decreases reducing oxygen available for combustion. By leaning the mix, you reduce the fuel flow to match the reduced oxygen.
improves efficiency: lower fuel consumption and better range and endurance
prevents engine problems: too rich mix can lead to carbon build up on spark plugs and engine roughness
What is static leaning and its purpose?
Static leaning is the process of adjusting the mix while the aircraft is stationary, typically before T/O from a high altitude airport
purpose of static leaning:
optimize engine performance for high-altitude operations - thinner air in higher altitude APs can cause the engine to run too rich on the ground
leaning the mixture during run-up ensures the engine produces max power for take-off
keeps engine smooth during prolonged ground operations
What is atmospheric stability?
Atmospheric stability refers to the tendency of the atmosphere to resist vertical motion of air.
it plays a significant role in determining weather patterns, cloud formation, and turbulence
stability is influenced by temps and moisture content of the air at different altitudes, and environmental lapse rate
stable air-typically leads to smoother, more predictable flight conditions with fewer clouds and less turbulence
unstable air- can create turbulence, increasing risk of convective turbulence, thunderstorm/severe weather
Stable atmosphere
Occurs when cooler air is trapped beneath warmer air (temp inversion), preventing vertical air movement
if air is displaced vertically, it will tend to return to its original position, resisting upward motion.
conditions
-air cools more slowly with altitude than the rising air
-results in clear skies, light winds, little cloud formation
-little to no vertical cloud development, leading to calm weather
Unstable atmosphere
occurs when warm air is beneath cooler air prompting vertical air movement
in an unstable atmosphere, air will continue to rise if it is displaced, since it is warmer and less dense than air surrounding it.
conditions
air rises, cools at slower rate, and remains warmer than surrounding air
-leads to formation of tall, cumulus clouds, turbulence
-weather TS, heavy cloud development, turbulence
Neutral Atmosphere
Occurs when air neither resists nor enhances vertical motion, meaning that if air is displaced, it will remain in its new position without returning to its original state
conditions:
-the temp lapse rate is similar to the rate at which rising air cools
-weather: a mix of conditions; clouds can form but usually do not develop vertically into TS
Factors influencing atmospheric stability
Environmental lapse rate (ELR): the rate at which the temp decreases w/ altitude
-if the ERL is > than the dry adiabatic lapse rate (rate of cooling of rising dry air) the atmosphere is unstable
-if the ELR is < than the moist diabolic lapse rate (rate of cooling saturated air) atmosphere is stable
clouds and weather:
-stable conditions produce stratus clouds (overcast)
-unstable conditions produce cumulus clouds/TS
This is your ppl check ride. Does your Aircraft need 100hr inspection?
100hr inspection is required for aircraft that are used for hire or flight training (flight school/rental as per FAR 91.409)
if the aircraft you are using is not being used for here or flight training (non-commercial AC, privately owned it does not need a 100hr inspection)
Yes, if I use a plane from coast, it will need a 100hr inspection
is the radius of a turn controlled by the bank angle or airspeed?
The radius of a turn is primarily controlled by the bank angle, but the airspeed also plays an important role. A greater bank angle results in a smaller turn radius, while a higher airspeed results in a larger turn radius
A steeper bank angle increases the horizontal component of lift, which directly contributes to turning the aircraft. More lift is needed to maintain altitude during a deeper bank for a tighter turn. The faster you fly, the more lift and bank is needed to maintain the same turn radius
What is a keel affect?
the keel effect is the stabilizing influence of the aircrafts vertical stabilizer and fuselage that resist unwanted sideslip and helps the aircraft maintain a more stable flight path, particularly in crosswind or sideslip conditions
This effect contributes to the aircraft directional stability and ease of control during certain flight maneuvers
while in the traffic pattern and making proper calls, you notice traffic on final for a different runway who has not made any calls
What do you do?
your primary goal is to maintain separation and avoid conflict while ensuring situational awareness and effective communication
if necessary, modify your pattern or hold until the traffic is clear, always prioritize safety over pattern adherence.
-maintain situational awareness
-announce your position and intentions
-avoid a conflict (alter pattern if necessary)
-monitor and attempt to communicate
-follow right of way rules
-report if necessary
Similarities of warm/cold occluded fronts
differences?
Both occluded fronts occur when a cold front overtakes a warm front, lifting warm air aloft.
Both produce similar weather, such as cloud cover and precipitation
they are different in their relative air temp behind and ahead of the warm front that distinguishes them, with cold occlusions being colder and more forceful
Which occlusion has worse weather?
Cold occlusion tends to produce worse weather than warm occlusions because:
the colder air behind the front is more dense, resulting in more abrupt lifting of the warm air. This leads to stronger vertical motion, which can produce: intense precipitation
thunderstorms
hail/turbulence
a warm occlusion usually has less severe weather because the air masses are closer in temperature
There are 2 types of occluded fronts
What are they?
cold occlusion- the air behind the overtaking cold front is colder than the air ahead of the warm front.
-when the cold front overtakes the warm front, it forces both the warm air and cooler air aloft.
warm occlusion-the air behind the overtaking cold front is warmer than air ahead of the warm front.
-when the cold front overtakes the warm front, it slides over the cooler air, lifting warm air between
What is the normal temp lapse rate?
dry adiabatic lapse rate?
wer adiabatic lapse rate?
A normal temp lapse rate is -2°c per 1000’ alt
the dry adiabatic lapse rate (DALR) and the wet adiabatic lapse rate (WALR) describe how the temperature of a parcel of air changes as it moves vertically in the atmosphere, depending on weather it is saturated or unsaturated
Dry adiabatic lapse rate
(DALR)
the rate at which an unsaturated parcel of air (air with relative humidity < 100%) cools as it rises or warms as it descends
-value: approx 3°c per 1000’
-why: when air rises, it expands due to lower pressure and this expansion causes air to cool
-when air descends it is compressed due to higher pressure causing it to warm.
-key: the cooling or warming occurs without heat exchange with the surrounding environment
Wet adiabatic lapse rate
(WALR)
the rate at which a saturated parcel of air (air with relative humidity of 100%) cools as it rises.
Value: typically 1.5°c - 3°c per 1,000’
Why: as saturated air rises, it cools and condenses, releasing latent heat of condensation.
-this released heat offsets some of the cooling, resulting in a slower cooling rate compared to the DALR
key: the WALR varies because the amount of latent heat released depends on the temp of the air; warm air holds more moisture and releases more heat
the body has 3 systems to detect orientation which are…
what happens when these systems provide the brain with conflicting info
which of the 3 systems is responsible for fixing false sensations
the vestibular, visual, and somatosensory system work together to detect orientation
conflicting info among these 3 systems leads to spatial disorientation
the visual system is responsible for correcting false sensation and ensuring accurate orientation, primarily through external references or instruments
Vestibular system
located in the inner ear
composed of the semicircular canals (detect angular acceleration) and otolith organs (detects acceleration and gravity)
detects changes in head movement and gravity
limits: susceptible to false sensation, such as the leans or graveyard spiral, especially with no visual reference
Visual system
provides brain with orientation info by interpret the position of objects relative to the horizon
most accurate and reliable system when clear external reference is available
limits: easily mislead by visual illusions such as runway width illusion or black-hole effect during night time landings
Somatosensory
Detect orientation and movement through sensory feedback from muscles, joints, and skin.
provides a sense of the bodies position and motion relative to itself
limits: weak for aviation; sensations of pressure, such as from acceleration or turns, can be misinterpreted, leading to false impressions of orientation
Tell me about the anti-icing equipment the cessna 172 does not have
The cessna 172 is not certified for flight into known icing conditions (FIKI) and should not be flown into weather where icing is likely.
Does not have:
heated leading edges
prop anti-icing system
anti ice windshield system
other pitot static heat system
engine inlet icing
What factors affect density altitude?
how does DA affect aircraft perform?
Do we want a low or high DA?
density altitude is affected by pressure, temps, humidity, and elevation.
pilots want a lower density altitude
DA can affect engine power, prop efficiency, lift, climb rate, and increased T/O/L distances
You are flying at 13,000MSL for 3 hours. what are your oxygen requirements?
what are the oxygen requirements for carrying passengers at 15,000 msl?
what is the FAR for this?
The flight crew will need supplemental oxygen, as we are flying between 12,500-14,000 MSL for over 30min
you are not required to carry supplemental oxygen for passengers at 15,000 msl, however above 15,000’ all occupants are required supplemental oxygen
FAR 91.211
What is a gimbal?
why does the standby attitude indicator have a dual gimbal?
a gimbal is a pivoted support that allows an object to rotate freely about one or more axis. in aviation instruments, gimbals are used to maintain the proper orientation of a gyroscope, allowing it to function effectively regardless of aircraft motion.
the standby attitude indicator uses a dual gimbal to maintain the gyros orientation and provide accurate pitch and roll info, even when the aircraft moves in multiple axes
describe the electrical system.
why does the alternator have a higher voltage than the battery?
the airplane is equiped with a 28 volt direct current (DC) electric system, consisting of a belt-driven 60 amp alternator and a 24 volt main battery and standby battery.
The higher output from the alternator is necessary to ensure the battery is charged and the aircrafts electrical needs are met. this design helps maintain a stable electrical environment and allows for reliable operations of all systems
What is the purpose of the counterweights in the ailerons?
How much do they weight?
counterweights help prevent flutter (a dangerous oscillation of control surfaces at high speeds). flutter can occur when aerodynamic forces on the ailerons cause them to vibrate uncontrollably. The counter weights help balance these forces and dampen vibrations by adding mass.
ailerons weight approximately 5-7 lbs
counterweights are approximately 1-3 lbs per aileron
What is maximum crosswind component of a cessna 172?
prove it
Maximum crosswind component on paved runway is 15kts
POH section 9
I received my PPL last month. Recently, I was diagnosed with sleep apnea.
Will I lose my PPL?
Will I lose my Medical?
Can I continue my career?
What is a special issuance authorization?
I will not lose my PPL directly, as long as I meet the medical requirements
I will be required to report my condition at the time of my next medical exam. The FAA may require treatment compliance does (such as CPAP machine logs) or issue a special issuance. (a medical cert for those with conditions that would automatically disqualify them)
Does not end airline career, but comes with stipulations
What is pilotage?
What is dead reckoning?
What is radio navigation?
Pilotage- is a method of navigation that involves using visual landmarks to determine your position and navigate to your destination, relying on charts/features.
Dead Reckoning- involves navigation by calculating your position based on a known starting point, heading, speed, time, and wind correction.
Radio navigation - uses electromagnetic signals and instruments to determine position and navigate. relies on ground - based or satellite navigation systems
Where is the Eustachian tube located?
What does it do?
What happens when it cannot equalize pressure?
a narrow passageway connecting the middle ear to the upper throat and back of nasal cavity
serves as a pressure - regulating pathway between the ear and the external environment
the primary role of the eustacian tube is to equalize air pressure on both sides of the eardrum
it allows air to flow into or out of the middle ear to match the atmospheric pressure
if blocked or unable to equalize pressure, barotrauma, hearing loss, pain, tinnitus, or a ruptured eardrum can occur
ICEFLAGS
Inversion - sensation of tumbling backward, caused by sudden transition from climb to level flight
Coriolis effect - sensation of turning or accelerating in a different direction caused by moving the head in a different plane (looking down) during prolonged turn.
Elevator Illusion - upward acceleration feels like the nose is pitching down. caused by a rapid upward or downward acceleration
False Horizon - A tilted or non level horizon caused by misinterpreting visual cues, like clouds, lights, terrain as horizon
Leans - sensation of banking in opposite direction of correction caused by a slow/unnoticed turn, followed by leveling wings
autokinesis - when the light appears to move/drift caused by staring at a stationary light in the dark for several seconds
Graveyard spiral - sensation of level flight while in spiral descent caused by prolonged turn in IMC inner ear no longer senses turn
Somotogravic Illusion - acceleration feels like nose - high deceleration feels nose - down caused by rapidly accelerating/decelerating
What is load factor?
what is the relationship between bank and angle and load factor?
what is the relationship between load factor and stall speed?
The ration of total lift generated by on aircraft wings to the aircrafts weight, expressed in multiples of Gs
in a turn, lift generated by wings must counteract both the aircrafts weight and centrifugal force due to turn. As bank angle increases, more lift is required to maintain altitude, increasing load factor
When load factor increases (during turns) the wings need to generate more lift to maintain flight. since lift depends on air-speed the stall speed increases with load factor
What 4 factors change air density?
“as pressure ___, density __”
As temp ___, density ___”
As altitude __, density___”
As humidity___, density___”
Air density is influenced by pressure, temperature, altitude, and humidity
Pressure increases, density increases
temp increases, density decreases
altitude increases, density decreases
humidity increases, density decreases
What is the airport beacon for a water base?
The airport beacon for a seaplane base (water base) has a unique light pattern to help identify it at night or in low visibility
Light Pattern - alternating while and yellow flashes repeating continuously
according to the ACS, what altitude do you need to be for
Ground reference?
Steep turns?
stalls?
Ground reference maneuvers - require between 600’ - 1000’ AGL, to observe ground references while maintaining a safe margin for recovery
Steep Turns - must be performed above 1,500’ AGL for a safe margin for recovery
Stalls - must be performed above 1,500’ AGL for ample space to recover
With the appropriate power setting, why could you theoretically float forever?
in ground effect, an aircraft experiences a unique aerodynamic condition where wingtip vortices are less pronounced and the downward deflection of airflow (downwash) is minimized.
the proximity to the ground enhances the wings lift due to altered pressure distribution around wing, allowing the aircraft to stay aloft at lower airspeeds and power setting
theoretically, the thrust can exactly counteract remaining drag, allowing the aircraft to maintain speed/altitude in ground effect
What 3 elements are needed for clouds to form?
How does invisible water vapor change into visible state?
Water Vapors - sufficient moisture in atmosphere
Cooling mechanism - air must cool to dew point (adiabatic cooling)
Condensation nuclei - tiny particles for water vapor condensation
Clouds form when moist air cools to the dew point and water vapors condenses onto particles and accumulate, transitioning from an invisible gas into visible droplets or crystals (clouds)
What is the utility category on W/B?
What maneuvers can we do in the utility category?
The utility category refers to a specific set of operational limits and design criteria for the aircraft. “limited aerobatic flight”
In a utility category, you are allowed to perform certain aerobatic maneuver, but are generally less extreme.
-chandelle (climb with change or heading)
-lazy eights
-steep turns (max bank usually 60°)
-shallow spins
-slight stalls ( power on/off
Where does the ADC (air data computer) get its raw data from?
What happens when you have an ADC failure?
The ADC processes data from the pitot tubes, static ports, temp probes, and sometimes AoA indicator
If the ADC fails, it can results in a loss of accurate airspeed altitude, and vertical speed rating, causing potential malfunctions in flight systems like the autopilot
pilot must be prepared to fly the AC manually and use the backup instruments in event of a failure
When can you log nigh time?
when can you log night time landings?
Differences between night time, sunset/sunrise, and civil twilight
Nighttime- the period between the end of civil twilight (evening) and the beginning of civil twilight (morning)
Civil twilight- refers to the time when the sun is between 6° below the horizon and the horizon
Sunset/sunrise- the moment the sun dips below the horizon, and the moment the sun appears above the horizon
to log night flight time, you must operate the aircraft between civil twilight
for night landings one hour after sunset and one hour before sunrise
sunset sunrise requires lights
What is the FAA OTC medical list? (over the counter)
What if a medication you need is on the list?
OTC over the counter medication list providing information about “go-no-go” medications
If I was using a medication on the No-Go list, I would
-refer to 61.52 to see if I am safe to fly with my condition
-consult my AME to make sure my meds are safe
-wait at least 5 dosage intervals after last dose before flying
There is no regulation on giving blood as a pilot but there is a FAA guide.
How long do you have to wait to fly as PIC or SIC after donating 1 unit of blood?
2 units?
What if you are showing symptoms?
One unit - 24 hrs recovery period and airman has no symptoms
two or more units - 72 hrs recovery and no symptoms
cannot fly if still showing symptoms
What weather can we expect during a cold/warm front?
after a cold/warm front?
Cold Front:
Before cloudy, possible TS, warmer temps
During: heavy rain/TS, rapid temp drop, wind shifts
After: clear skies, cooler drier air, gusty winds
Warm Front
Before: increasing clouds, light rain/drizzle, cooler temps
During: stratus clouds, steady rain, gradual temp rise
After: milder temps, clearing skies, possible residual clouds
What is the difference in payload and useful load?
Usueful load is the total weight an AC can carry, including pilot, Pax, baggage and usable fuel.
-useful load=Max T/O weight BEW
Payload-refers to the weight of the Pax, baggage, and cargo excluding fuel
Payload= useful load - fuel weight
What are the two types of stability?
What kind of stability does the cessna 172 have?
can you have positive dynamic stability with negative static stability?
The two types of stability are dynamic and static
the cessna 172 has positive static and dynamic stability, making it forgiving and easy to fly
positive dynamic stability requires positive static stability you cannot have one without the other
Define ADC
Dafine AHRS
Air Data Computer is an onboard avionics system that collects processes and provides air data info to other AC systems and pilot with inputs from pitot static system and others
-provides: IAS, TAS, Altitude, VSI, OAT, DA, Wind info
Attitude and Heading Reference system is a digital system providing precise attitude (pitch and roll) heading and yaw information. it uses sensors like gyroscopes, accelerometers and magnetometers replacing traditional gyro instrument
-provides: attitude, Heading, Turn Rate, PFD data, Autopilot stability
What is the lift Formula?
Which two factors can the pilot control?
L=Cl x 1/2 pV2 x S
L=Lift force
Cl=Coefficient of lift
p=air density
V=TAS
S=Wing surface area
x=multiply
the pilot can change the coefficient of lift by adjusting the AoA. Increasing the AoA increases Cl, thereby increasing lift
the pilot can control airspeed using throttle and pitch. Increasing airspeed increases V2 which has significant effect on lift since velocity is squared in the equation
Do day landings count for night currency?
Do night landings count for day currency?
Why?
Day landings do not count for night currency because night landings involve unique challenges that must be practiced specifically
Night landings do count for day currency because the skills required exceed those needed for day
What are the types of airspeed?
What are the types of altitudes?
Airspeed
IAS- airspeed displayed used for performance
CAS-IAS corrected for instrument error, for performance chart
EAS- CAS corrected for compressibility effects at higher speeds
TAS-actual speed of the aircraft through the air
GS- AC speed over the terrain GS=TAS =-Wind component
What are the types of altitudes?
Indicated Altitude-altitude on altimeter @ local baro setting
Pressure Altitude-altitude indicated when set 29.92
Density Altitude-pressure alt corrected for temp/humidity
True altitude-actual height of AC above MSL
Abolute Altitude: Height of AC above the terrain
What does the impulse coupling do for magneto
Boosts sparks energy for staring:
During startup the engine is turning at a relatively low RPM, which reduces the energy generated by the magneto
The impulse coupling momentarily increases the rotational speed of the magneto, producing a stronger spark to ignite the fuel air mixture in the cylinders
retards the spark timing:
Magnetos normally fire at a fixed timing relative to the engines rotation but this start the impulse coupling delays the spark to occur closer to top
How does an impulse coupling work?
The impulse coupling consist of
Spring mechanisms-stores energy as engine rotates @ startup
Command flyweight assembly - controls the release of the spring and ensures precise timing
-as engine rotates, the IC locks momentarily (using flyweights) allowing the spring to wind up and store energy
-when spring releases it briefly spins magneto rapidly
-this rapid spin produces more powerful spark to spark plug
-The spark is also delayed to occur at optimal starting time
-
What is ATIS, ASOS, AWOS?
Automatic Terminal Information Service
-is a continuous broadcast of recorded non-control info at airports, designed to reduce the workload of ATC.
-weather, active runways, NOTAMS, other details
Automated Surface Observation System - is an automated system that measures, collects, and reports detailed surface weather observations, including: winds, visibility, precipitation, temp/ dewpoint , altimeter, sky conditions
Automated weather observation system - similar to asos but less comprehensive weather data. for smaller APs
Threshold stripes indicate runway width
how wide is a runway with 4,6,8,12,16?
4-60’
6-75’
8-100’
12-150’
16-200’
What is a squall line?
What is an embedded TS?
A squall line is a continous line of TS, often extending for hundreds of miles, usually associated with a cold front or ahead of it. It is a type of mesoscale convective system and forms in unstable atmospheric conditions
-extremely hazardous to AC due to turbulence and WS
Embedded TS are hidden within other weather systems, making them hard to detect/avoid without proper equipment.
Both present significant hazards to aviation, requiring careful planning and inflight adjustments
Difference between part 61 and 91?
What information do you find in part 830?
Part 61 - certification of pilots, flight instructors, and ground instructors.
Governs the reqs for pilot cert and training
Part 91 - General operating and flight rules
Governs operations of aircraft within US
Part 830 - notifications and reporting of AC accidents/incidents
outlines reqs for reporting accidents, incidents, and overdue AC to the national transportation safety board
What is the procedure for accidentally flying in a storm?
Stay calm
Maintain control
Reduce airspeed to minimize structural damage risk
if storm is localized and can safely turn around, do so with a shallow bank
use instruments to avoid special disorientation
communicate with ATC “VFR pilot in IFR conditions”
inform of current position, altitude, heading, request vectors
climb or decent if necessary and cautiously
land in nearest suitable airport
Where does interference drag occur on the aircraft?
Give an example of an aircraft with less form drag than a 172
Interference drag - occurs where different parts of the AC meet and their airflow patterns interact. it is caused by the mixing of airflow from these intersecting components creating turbulence and increased drag.
-Wing fuselage intersections
-strut and landing gear attachments
-tail/empennage joints
A cirrus SR22 has less drag as it is designed with a laminar-flow fuselage and smooth retractable wheel fairing
Explain the autopilot system
What is servomechanism?
The autopilot system leverages servomechanisms to translate the commands from the flight computer into precise movements of the aircrafts control surfaces. This allows for controlled and efficient flight operations with minimal manual input from the pilot
A servomechanism - is a system that uses feedback to control the motion and position of mechanical components such as control surfaces on a aircraft
How does autopilot work?
The flight control computer processes inputs from the aircrafts sensors (gyro, accelerometers, gps, altimeter) sends commands to control surfaces to maintain flight
sensors provide the FCC with data
Servomechanisms (actuators) are the mechanical systems that physically move the ACs control surfaces
Control Panel allows pilot to input desired flight parameters such as attitude, heading, vertical speed
feedback systems continuously monitor and adjust the control surfaces to maintain precise control
How servomechanisms work?
Input signals - the fcc sends a command to the servomechanisms to move a control surface
motor actuator - a small electric motor or hydraulic actuator moves the control surface based on the command
feedback loop - sensors provide real time data about the position of the control surface to ensure it matches desired input. servomech fixes discrepancies
What is fog?
What are the types of fog?
S
U
G
A
R
P
I
What is fog?
What are the types of fog?
Fog is visible mass of tiny water droplets or ice crystals suspended near earths surface. Forms when air temps drop to dewpoint.
S-steam
U-upslope
G-ground
A-advection
R-radiation
P-precipitation
I-Ice
What are the only 3 sources for legal weather briefing when filing a flight plan?
Why are these the only ones?
Flight service station FSS(1800-WX-brief)
Direct user access terminal service (DUATS) foreflight / Garmin pilot
NOAA/FAA approve service- aviation weather center (AWC)
Provide, data directly, from NWS and FAA approved
Explain Dihedral
Does the Cessna 172 have dihedral?
What is it called when wings are designed downward instead?
Dihedral wings are designed with an upward angle from horizontal plane. This upward slope provides roll stability.
When the AC rolls to one side, the wing that dips lower has a steeper AoA relative to oncoming airflow. This generates more lift on the lower wing, causing the AC to naturally roll back level.
Yes Cessna 172 has Dihedral wings
Anhedral wing slope down for more maneuverability
What are 2 types of drag?
Explain the 2 types of _______ drag?
Induced drag - is a by product of lift. Results from the vortices created at the wingtips, which cause downwash and reduce effective AoA
Parasitic Drag - unrelated to lift, caused by the aircraft’s moving through the air
Types of parasitic drag:
Form Drag (fuselage, antennas, bulky components)
Skin friction Drag (rivets, dirt, chipped paint)
Interference Drag ( wings/fuselage, landing gear struts)
PAPI VS VASI?
Precision Approach Path Indicator (PAPI) is a system of 4 horizontal lights usually left of runways. Each light changes color based on angle of approach: white = above the glide slope , red = below the glide slope. (Provides a more precise glide path info than a VASI
Visual Approach Slope Indicator (VASI) is a system of 2 rows of lights (near the far bars) - 2 bar VASI = standard set up for 3° glidepath
-3bar VASI = adds third bar for higher glide paths
What is the ELT?
Where is it on the aircraft?
How often does it need to be inspected?
When does it need to be replaced?
Which FAR gives this info?
Emergency locator Transmitter (ELT) is a device installed in an AC that broadcasts a distress signal on emergency frequencies (121.5, 243, 406) in a crash or ON
Typically located in rear fuselage for survivability
Per 91.207 must be inspected every 12 calendar months
Must be replaced after 1hr of consecutive use or 1/2 of battery life
How does the stall warning horn work?
The stall warning horn activates when AC is approaching critical AoA
It uses a sensor (stall vane) mounted on the leading edge to detect AoA
When AoA gets too high, a suction (neg pressure) in the vane triggers the horn
What are the 3 types of heat transfer?
Explain them
Conduction - heat transfer through direct contact EX: a metal spoon in a hot coffee becomes hot
Convection - heat transfer though movement of fluids. EX: in a pot of boiling water hot water rises cooler water moves down similar to winds in atmosphere
Radiation - Heat transfer though electromagnetic waves moves typically infrared radiation EX: the warmth from a sun in through radiation
What is the equivalent airspeed?
When do we use it?
Equivalent Airspeed is IAS adjusted for change in air density with altitude so it represents the actual dynamic pressure on the aircraft’s surface, similar to what the aircraft would experience at sea level under standard conditions.
Primarily used in high speed flight and at high altitudes to account for decreasing air density as the aircraft climbs. Give a more accurate measure of aircraft performance/aerodynamic as it compensates for altitude/AD effects
Describe vapor lock
Vapor lock occurs when the engine fuel turns to vapor due to excessive heat, causing a discruption in fuel flow
Systems: engine stalling / power loss difficulty restarting engine rough running engine
Recovery: reduce engine power to decreased fuel demand wait for fuel system to cool re-prime engine to give it some shots of fuel
Choosing an altitude for your cross country is based on which FAR?
Is the FAR based on the true or magnetic?
91.119 specifies the minimum safe altitude for cross-country flight
Based off of true heading
Describe a carburetor
What is the main principle behind a venturi?
Cessna 172 uses a float type caraburetor to mix duel and air before it enters the engine for combustion
The carburetors Jon is to regulate the mixture of fuel and air to ensure the engine runs efficiently under varying flight conditions
The Venturi is a constriction of the carburetors air passage it is a tube that narrows in the center and widens again. Uses Bernoulli’s principle
Function of carburetor
Air enters the carburetor though filter to clean incoming air
As air moves through the carb, fuel is drawn into the airstream through jet or nozzle, creating mixture of air and fuel.
The Venturi creates a drop in air pressure drawing fuel into the airstream creating desired fuel air mix
Mixture of fuel and air controlled by mix control knob
Throttle control valve controls volume of air entering carb. More air = more power
When throttle is idle a separate idle jet allows fuel to continue flowing to keep engine running @ low RPM
Venturi Function
Venturi is a constricted section of carb passage. As air flows through the Venturi airspeed increases in the narrow section due to reduced area creating a low pressure zone in throat of Venturi (Bernoulli’s principle)
The low pressure area in Venturi draws fuel from the duel bowl through fuel jet. The fuel mixes with high speed air flowing through the Venturi forming an air duel mix that enters the engine
Ensures fuel atomized efficiently meaning it is broken into fine droplets for efficient combustion
Describe hydraulic braking system
Are the mains vs the nose struts the same?
When the pilot pressure to the brakes hydraulic pressure is transmitted through hydraulic lines to the brake calipers squeezing the brakes slowing the AC.
The left and right brakes can be operated independently allowing for differential braking to assist for tight turns.
The main gear uses spring steel struts. These are fixed gear and do not affect braking directly.
The nose gear strut uses an oleo pneumatic shock absorber dampening load while landing/ taxi
Can I use the Redbirds AATD for my PPL check ride?
Per FAA 14cfr 61.109 an AATD can be used to credit up to 2.5 hours of the total 40 hour minimum training requirement in an AATD
The private pilot practical test must be completed in an actual aircraft that meets the FAA regs for the test
Stabilized approach
An approach which the pilot establishes and maintains a constant angle glide path towards a point on the runway
A stabilized landing point appears to be stationary
A go around if unable to stabilize approach but 500ft in VMC
A go around if unable to establish approach by 1000ft IMC
The typical GA aircraft should go around if unstable below 300’
Glidepath 3° to touchdown zone on runway
Heading/airspeed maintain centerline and +10/-5 it’s land speed
Configuration AC in correct landing configuration (flaps trim gear)
Descent rate generally 500-1000 FPM in light aircraft
Power setting use power setting appropriate in AFM
Briefing and checklist prior to initiating approach
Wingtip Vortices
When air tends to flow from the high pressure area below the tip, upward to the low pressure area on the upper surface.
In the vicinity of the tips, there is a tendency for these pressures to equalize resulting in a lateral flow outward from the underside to the upper surface. This lateral flow imparts a rotational velocity to the air at the tips creating trailing vortices. These vortices circulate counterclockwise about the right tip and clockwise off the left.
Areas stability in an aircraft affect significantly
Maneuverability t- the quality of an aircraft that permits it to be maneuvered easily and to withstand the stresses imposed by maneuvers. Governed by the aircraft’s weight, inertia size, location of flight controls, structure strength, and power plant. An aircraft design characteristic
Controllability - the capability of an aircraft to respond to the pilots control, especially with regard to flight path and attitude. It is the quality of the aircraft’s response to the pilot pilots control application when maneuvering the aircraft regardless of its stability characteristics
Directional stability (yawing)
Stability about the aircraft’s vertical axis (the sideways movement) is called yawing or directional stability. Yawing or DS is the most easily achieved stability in the AC design.
The area of the vertical fin and the sides of the fuselage aft of the CG are the prime contributors that make the aircraft like the well known weather vane or arrow pointing its nose into the relative wind
Lateral Stability
(Rolling) Stability about the AC longitudinal axis, which extends from the nose of the aircraft to the tail.
Positive lateral stability helps stabilize the lateral or rolling effect when one wing gets Lowe than the wing on the opposite side of the aircraft.
There are four main design factors that make an aircraft laterally stable:
Dihedral
Sweep back
Keel affect
Weight distribution
Longitudinal stability (pitch)
Longitudinal stability is the quality that makes an aircraft stable about its lateral axis. It involves the pitching motion of the aircraft’s nose
Static longitudinal stability is dependent upon 3 factors
Location of wing w/ respect to the CG
Location of horizontal tail surfaces w/ respect to the CG
Area or size of tail surface
Parasitic drag
Comprised of all the forces that work to slow the aircraft’s movement
It is the drag not associated with the production of lift
This includes the sidplacement of air by aircraft, turbulence generated in airstream, or a hinderance of air moving over the aircraft/ airfoil
There are three types of parasitic drag: form, interference, and skin friction
Skin friction drag
The aerodynamic resistance due to the contact of moving air with the surface of an aircraft.
Each layer of molecules above the surface moves slightly faster until the molecules are moving at the velocity of the aircraft’s nose Static moving around the aircraft. This speed is called the free stream velocity.
The area between the wing and free stream velocity level ()about as wide as a card) is called the boundary layer
To reduce the effect of skin friction drag, aircraft’s are designed using flush components (rivets)
Interference Drag
Comes from the intersection of airstreams that create eddy currents turbulence or restricts smooth airflow. EX: intersection of wing and fuselage at wing root. Air flowing over fuselage meets air flowing over original currents
The most interference drag is observed when two surfaces meet at perpendicular angles
Fairing and distance between lifting surfaces and external components reduce interference drag
Form Drag
The portion of parasite drag generated by the aircraft due to its shape and airflow around it. EX: cowlings, antennas, shape or other components
When the air has to separate to move around a moving aircraft and its components it eventually rejoins after passing the body. how quickly and smoothly it rejoins represents the resistance it creates, which requires additional force to overcome
Induced drag
“The penalty incurred by airfoil producing lift” in level flight the aerodynamic properties of a wing or rotor produce a required lift, but this can be obtained only at the expense of a penalty/
The penalty is called induced drag
Induced drag is inherent whenever an airfoil is producing lift and is inseparable from the production of lift.
It is always present is lift is produced
What is the difference between true course and magnetic course?
Why does variation exist?
Where do you find variation on the section chart? What are these called?
True course (TC) the AC intended path over the ground measured relative to true north
Magnetic course (MC) the AC intended path relative to magnetic north (the direction of earths magnetic field)
-obtained by adjusting TC for magnetic variation
Magnetic variation (or declination) is the angle between true north and magnetic north at a specific location
-variation is shown on sectional charts using Isogonic lines
Isogonic lines- which are magenta dashed and labeled w/ variation value. (West is best +, East is least -)
Can I operate an aircraft for hire with more than 200 horsepower?
Why?
No, PPL may not fly for compensation or hire without a commercial certificate
What is 91.103 and how does it apply to you?
How do you find known ATC delays?
FAR 91.103 (preflight action) specifies that responsibilities of the pilot in command regarding preflight planning for every flight, including NOTAMS, Weather, known ATC delays, runway info, Alternates, fuel regs, TB/L info
Known atc delays can be found through NOTAMS, flight service station (1800-WX-Brief) and planning apps
As I am flying at night on a calm evening with some clouds, I seem to be flying level with the horizon but my attitude indicator says I am 5° pitched up
What illusion am I experiencing?
Likely experiencing the False Horizon Illusion a visual illusion encountered during night flight or in conditions where the natural horizon is obscured by clouds or terrain
This illusion occurs when a pilot mistakingly perceives something other than the true horizon as the reference for level flight
Describe the two principles of lift
Bernoullis Principle - The speed of a fluid (air) increases, its pressure decreases. As the AC flys forward the air flows faster over the curved upper surface this creates a pressure difference with the higher pressure under the wind pushing up
Newtons 3rd law as air flows faster over the wings it is deflected downward forces on the air, the air exerts on equal/opposite upward forces on wings (lift)
Where do the 3 fuel sumps under the cowling pull fuel from?
Fuel selector valve
Fuel reservoir
Drain Valve
You are flying west at 4,500 MSL all of a sudden you feel engine roughness
How do you troubleshoot?
What could be the potential cause?
Issues could be carb ice, improper mixture, Mag/spark plug fouling, fuel contamination/starvation or mechanical issues
Check instruments. Low oil pressure/high temps could be mechanical issues, rpm could mean fuel ignition
Adjust mixture/ make sure not to lean/rich
Carb heart- turn on for cool/himid conditions
Switch fuel tanks/fuel shutoff valve open
Cycle mags use better performers, lean mix/run higher rpm
If sp fouling suspected
During the brake check you notice the brakes feel slightly spongy / soft…
What do you do?
What do you think is the cause?
Could be cause by: air in brake lines (most common cause of sponginess)
Low or contaminated fluid (can cause sponginess)
Warn or damaged parts (warn pads, damaged calipers, flexible brakes lines can result in soft brakes)
Then I would pump brakes to build pressure inspect for brake fluid leaks check fluid levels
I would abort flight call mechanic log issue
What is the Coanda effect?
Why do we care about it?
The coanda effect is when air flows over a wing or any curved surface, the airflow doesn’t just detach and continue straight but rather stay attached to the surface following its shape
Understanding this effect helps explain how AC wings generate lift maintain smooth airflow over control surfaces and how high-lift devices enhance performance
Where does the AHRS get its raw data from?
What happens when you have an AHRS failure?
The attitude heading reference system (AHRS) provides attitude and heading data for AC. It gets its raw data from accelerometers, gyroscopes, magnometers, and air data sensors.
In case of AHRS failure the pilot may experience a loss of flight instruments
The AHRS system runs off an internal measurement unit. This unit contains what instrument
accelerometers - measures linear acceleration along the 3 axes (longitudinal, lateral, and vertical)
3 gyroscopes - measures the rate of rotation (angular velocity) around 3 axes of the AC
3 magnometers - (magnetic sensors) - measures the earths magnetic field along the 3 axes
Formation, dissipation, and redistribution of weather is the result of ________
What are the 3 types of _______ forces?
Explain them
3 atmospheric forces, they are:
Pressure gradient Force (PGF) - initiates the movement of air and development of weather system
Coriolis force alters the direction of winds and shapes larger scale circulation patterns
Frictional force - influences wind near the earths surface and contributes turbulence /change
Pressure gradient force
Force that results from differences in air pressure. The grater the pressure difference over a given distance the stronger the force. This movement of air drives wind and weather systems like cyclones and fronts
PGF is responsible for initiating wind flow and the development of weather systems. A steep pressure gradient leads to stronger winds while a weak gradient leads to lighter winds
Coriolis force
Force caused by earths rotation. It deflects moving air to the right in the northern hemisphere and to the left in the southern hemisphere. This deflection changes the direction of winds and is important for large scale atmospheric circulation
Responsible for rotation of weather systems such as cyclones (counterclockwise in northern hemisphere) and influences ocean currents/ doesn’t change wind speed but alters flow
Frictional force
The resistant force that earths surface exerts on the movement of air. This force decreases w/ altitude.
Affects weather near earths surface slowing it down and causing it to change ddirection. Especially near landforms like mountains cities.
Influences the boundary layers of the atmosphere which can lead to turbulent weather
During preflight you notice the left wing has indented inward and the fuel drain under the wing is blocked
What happened?
Why?
If the fuel drain is blocked it could be due to a clogged fuel system or frozen fuel.
This blockage might create a pressure buildup or a vacuum within the wings fuel tank, which could lead to deformation of the wings structure
When do we use the alternate static source?
How do we know when to use it?
What will the alt static source do to our instruments
According to POH section 3 “if erroneous readings of static source instruments (airspeed, altimeter, VSI) are suspected, the alt static source air valve should be pulled ON, supplying static pressure to these instruments from the cabin.”
When ALT static air valve is on the max airspeed variation from normal operation is 6 kts and the max altimeter variation is 50ft with windows closed
How do the four strokes of the engine time themselves?
Where is the camshaft in relation to the crankshaft?
What does the cam/crankshaft do?
A camshaft is key to timing valves. Its rotates at half the speed of the crankshaft because it is driven by the crankshaft through a gear. The camshaft has lobes that a push against the valve lifters causing the intake and exhaust valves to open and close at the right times
The crankshaft is located above the camshaft and rotates each piston movement. Its rotation is responsible for driving the camshaft which in turn controls the timing of the valves
What is Va?
Does Va change? Why?
How do you calculate Va?
Maneuvering speed
Yes, Va changes with AC weight because stall speed changes with weight.
Higher weight - higher VA
Lower weight - lower Va
If the Va at max gross weight (2,550) is 105kts, and the AC current weight is 2,000lbs VA new = 105 square root 2000/2550 =105x 884=92.8kts
You start the engine and your standby attitude indicator reads a 20° bank to the left
What would you do? Why?
Allow time for the gyro to stabilize it can take 5 min to fully spin and stabilize
Cross check with the primary attitude indicator to ensure AC is level
tap instrument lightly to get it unstuck
Abort flight if issue persists
What are the two classifications of moisture for an airmass?
As air masses move around the world can they acquire different characteristics?
Air masses are classified by their moisture content and are cateregorized based on their origin.
Continental (C) dry air masses formed over land
Maritime (M) moist air masses formed over water
Additional airmasses classified by temps
Tropical (T) warm masses formed in low latitudes
Polar(P) cold masses formed in higher latitudes
Artic(a) very cold masses formed near poles
Yes airmasses can acquire different characteristics
I have my private pilot SEL and would like to add multi engine rating
Where could I find info regarding PPL check ride additional rating
Airman certification standards (ACS) for multi engine rating standards
FAR 61.39 prereqs for practical test
FAR 61.63 additional class ratings
About the inside of the AC
What is a GIA?
What many do we use?
What do they do?
Garmin Integrated Avionics Unit (GIA) serves as the main processing and communication hub integrating various functions in single unit
Flight management processing data and managing inputs from gps, vor, ils, other nav systems
Communucation VHF radio for comms with ATC
NAV radios enabling reception of VOR ILS signals
Engine/airframe interface such as instruments
Autopilot interface
We use 2 for display/redundancy
Oh no! Your pitot tube became blocked in flight. How did you recognize the problem?
How can you troubleshoot the problem?
If my pitot tube was blocked I would notice it on my airspeed indicator
It would show an increase with altitude if RAM air and Drain were blocked
It would indicate 0 airspeed if RAM air blocked
What is the CG range of the Cessna 172s?
Is the R model different?
Forward 35 inches aft of datum @1950lbs or less and 41inches aft of datum at 2550lbs
AFT 47.3 in aft of datum at all weights
The CG range for the 172r is:
Forward: 35 inches aft of datum @ 1950lbs or less and 40in aft at 2450lbs
AFT 47.3 in aft at all weights
What does pilot controlled lighting mean?
How does we use it?
Pilot controlled lighting refers to airports lights that can be activated and adjusted by pilots using the aircraft radio to improve visibility during arrival / departure (L on sectional, L* = request)
Suggested use is to always initially key the mic 7 time to assure lights are turned on brightest.
7 times brightest lights
5 times medium lights
3 times lowest setting
Why is the distance to clear a 50’ a stable longer than the mortal ground roll?
The distance required to clear a 50’ obstacle is longer because it includes both the distance to accelerate to takeoff speed(ground roll) and the additional distance needed to climb to altitude needed to clear obstacle
While flying you notice a “low volts” indicator”
What steps do you take?
Does the PHO give you a min volt #?
Master switch (alt only) off
Alt field circuit breaker - check in
Master switch (alt/battery) on
Low volts annuciator - check off
Bus volts - check charging (+)
If low volts annuciator still on
Master switch alt only off
Electrical load reduce immediately : avionics 1 pilot heat all lights, cabin power OFF
What document must be in your possession while operating as PIC of an AC as a student pilot?
Does this change after becoming a private pilot?
As a student pilot a am required to have in my possession while PIC:
Student pilot cert
Government issued photo ID
Medical cert
Logbook with instructor endorsements
61.3 as a private pilot I no longer need to have my logbook on me
Convective air currents happen due to ______
Updrafts are more likely to occur over ______
Downdrafts are more likely to occur over ______
Uneven heating and cooling of earths surface. This causes warm air to rise and become less dense, causing updrafts. As warm air rises, it cools condenses and may eventually fall creating downdrafts
Updrafts more likely over warmer surfaces
Downdrafts more likely over cooler areas or regions of precipitation
In your preflight you discover frost on your wings, what do you do?
How much ice is too much?
DO not attempt to fly. Frost can affect the airflow over the wings and significantly degrade the ACs lift and control
I could attempt to remove the ice with a scraper or de-icing solution, or consult ground crew. It would have to be remove completely
Any visible ice on control surfaces is too much
Down wash
As air and vorticies roll off the back of your wing they angle down which is known as downwash
Downwash points the relative wind downward so the more downwash you have the more your relative wind points downward
More downwash = more induced drag
Stability
The inherent quality of an aircraft to correct for conditions that may disturb its equilibrium and to return to or continue original flight path
If an aircraft is to fly straight and steady along any arbitrary flight path, the forces acting on it must be in static equilibrium
The reaction of any body when its equilibrium is disturbed is stability. The 2 stability types are dynamic and static
Dynamic stability
The initial tendency to return to equilibrium that the aircraft displays after disturbed from its trimmed condition
Refers to the aircraft response when disturbed from a given pitch yaw or bank the threee types are
Positive dynamic stability
Neutral dynamic stability
Negative dynamic stability
3 types of dynamic stability
Positive dynamic stability - over time the motion of the displaced object decreases in amplitude and because it is positive the object displaced returns toward the equilibrium state
Neutral dynamic stability - once displaced the displaced object neither decreases nor increases in amplitude. A worm shock absorber exhibits this tendency
Negative dynamic stability - over time the motion of the displaced object increases and becomes more divergent
Static stability
The initial tendency direction of movement back to equilibrium. In aviation it refers to the aircraft’s initial response when disturbed from a given pitch yaw and bank
Positive static stability the initial tendency of the aircraft to return to equilibrium after disturbed
Neutral static stability initial tendency of the aircraft to remain in a new condition after disturbed
Negative static stability initial tendency of the aircraft to continue away from original static of equilibrium after disturbed
What is a TCDS and where can I find it?
A type certificate data sheet is a document that contains detailed information about the aircraft, engine, or prop approved by the FAA or EASE
Often referred to as an aircraft “birth certificate”
In outlines the critical parameters that an aircraft must meet to be considered airworthy. It includes
Dimensions, wing loading, limiting airspeed, reg marks and placards, control surface fraud, engine instillation, engine prop control, max struct weight, fuel capacity
It can be found on the FAA website or FSDO
Moment
The mathematical measure of an aircraft’s tendency to rotate about it CG.
Equal to the product of the force applied and the distance at which the force is applied
A moment arm is the distance from a datum (reference point/line) to the applied force.
Moment = arm distance X weight
What happens to total lift during a turn?
The vertical component of lift counters gravity but in a turn the total lift must increase to maintain altitude because some of the lift is being used to generate centripical force needed for the turn
To compensate for this AoA or airspeed must increase to generate more lift during turn
Total lift in a turn increases to counteract the combined effects of gravity and centripetal force needed to maintain the turn
What is centripedal and centrifugal force
Centripedal force is acting on an object moving in a circular path directed toward the center of the circle of curvature of the path
Centrifugal force pseudo force that is perceived by an observer in a rotating reference frame not an actual force but operantly force seeming to push outward
While centripedal force is actually force that causes AC to turn. Centrifugal is that is felt as reaction to turn
What is the time of useful conciousness?
How much time does a pilot have to make rational decisions at 45,000’ MSL without oxygen?
Time of useful consciousness (TUC) refers to the period of time a person can perform useful task or make rational decisions after onset hypoxia due to decrease atmospheric pressure, like high altitudes.
at 45,000 the TUC without supplemental oxygen is extremely limited, ranging from 9-15 seconds
What do we call TAS corrected for wind?
Give an example of when you would use ground speed during a CC
Ground speed is the TAS corrected for wind, and it represents the ACs actual speed above the ground
It is especially useful during cross country flights for estimating arrival times and adjusting your course based on wind corrections
When do you get into ground effect?
When does the cessna 172s get into ground effect?
Ground effect occurs when an aircraft is flying close to the ground, typically within one wingspan or less above surface
The cessna 172 has a wingspan of about 36’. therefore ground effect generally starts to occur when AC is 36’ or less above the ground. Though it is more pronounced as you get lower like half the wingspan
get a paper chart supplement
Maintenance log
look for a page that has the maintenance log
last required inspections go ask to see the paper maintenance log
flight plan
coms gps below it at the base
netween coms is the OAT
nag 1 2
elt is at the empanase
transponder fin like at the bottom
marker beacon is short long one
What is the relationship between angle of bank and stall speed?
“as bank _____, stall speed ____”
what is the relationship between flaps
As the bank angle increases the stall speed increases due to a higher load factor and the need for more lift.
Flaps lower the stall speed, allowing the AC to fly at slower speeds before reaching the stall angle of attack but they also increase drag
The skys are nice and smooth but they visibility is garbage…
what kid of atmosphere stability is this?
Stable atmospheric conditions are usually present when skies are smooth and visibility is poor, typically because the air does not support vertical mixing needed to disperse moisture or pollutions
What is NOTAM?
Who issues NOTAMS?
what are the different kinds of NOTAMS?
where can i find NOTAMS that may affect my flight?
A NOTAM is an official notification or advisory issued to inform pilots of safety info for flights
Issued by FAA national authorities airport operators and others
Types NOTAM D, FDC, LNOTAM, MNOTAM, MILITARY
Where to find: FAA NOTAMS search flight plan tools, ATIS, DUATS, FSS
Types of NOTAMS
notam D: provides info about changes to aeronautical facilities, services, procedures (AP info)
FDC Notams: issued for regulatory or procedural changes affecting flight. (TFR, airspace, approach)
L Notam: info relevant to specific location or a smaller area
M Notam: covers range of info such as emergency response instructions or temp airfield closures
Military: specific to military operations that could affect civilian traffic
What are the 7 types of turbulence
Which type of turbulence poses a particular threat to Vs and why?
Clear air turbulence - occurs in clear skies, where diff air masses meet cannot be detected
mechanical - caused by air flowing over obstacles
Thermal (convective) - caused by rising warm air
Wake - caused by wingtip vortices of larger AC
5 mountain wave - occurs when strong winds blow over mountain ranges extending far downward
frontal - associated with fronts, where different air masses collide and mix violently. (WS/ Precip)
TS - caused by strong updraft / downdrafts inside TS
