General Flashcards
How does temperature affect takeoff distance and performance?
The colder the air the denser . Dense air has more air molecules for the propeller to grab and thrust the aircraft forward.
Thus, lower temperatures equal greater aircraft performance. Colder temperatures mean shorter takeoff distance and shorter landing distance required.
How do calculate pressure altitude without using an altimeter?
Pressure altitude = (standard pressure- current pressure setting) x 1000 + field elevation.
Example: altimeter30.01 and field elevation 6,000 feet.
Pressure altitude = (29.92- 30.01)x 1000+ 6000’= 5910’
How do you calculate density altitude?
Density altitude= pressure altitude+ 120(actual outside air temp(celsius)- standard temp(celcius))
what is camber? Can it be changed?
The curvature of the wing
It is changed by extending or retracting flaps
What is chord line?
An imaginary straight line connecting the leading and trailing edge of an airfoil.
What is the angle of incidence? Can it be changed?
The acute angle formed between the chord line of an airfoil and the longitudinal axis of the aircraft. It cannot be changed.
What is center of gravity?
The point at which the aircraft would balance if it were suspended at that point.
What are the effects of an aft center of gravity?
1.Decreased longitudinal stability
2. Faster cruise speed due to reduced drag.
3.Lower stall speed due to less wing loading.
4.Poor stall/spin recovery
5.Quick rotation on takeoff
6.possibility of flaring too much and tail striking on landing.
What are the effects of forward center of gravity?
1.Increased longitudinal(pitch) stability
2.Lower cruise speed due to increased drag.
3.Higher stall speed due to increased wing loading.
4.More back pressure required to maintain level flight.
5.Longer takeoff distance and harder to rotate on takeoff.
What does an increase in load factor have on stall speed?
An increase in load factor indicates a heavily loaded plane, resulting in a higher stall speed and making stalls possible at seemingly safe speeds.
A higher Angle of attack is required to generate the required lift. Too high of a load factor can also result in structural failure.
What is load factor?
The ratio between the lift generated by an aircraft’s wings at any given time to the total weight of the aircraft, expressed in g’s
What is the relationship between maneuvering speed and weight?
1.Maneuvering speed decreases with lighter gross aircraft weight because there is less weight to stabilize the aircraft.
2.light aircraft can get thrown around in turbulence easier.
3.For example, Va may be 100 knots when airplane is heavily loaded, but only 90 knots when the load is light.
What is standard empty weight?
Weight of airframe, engines, and operating equipment that have fixed locations and are permanently installed in the aircraft including fixed ballast, hydraulic fluid, unusable fuel and full engine oil.
What is basic empty weight?
Standard empty weight plus the weight of all optional and special equipment that have been installed.
What is useful load?
Difference between Max Gross weight and basic empty weight; weight of the pilot, copilot, passengers, baggage, usable fuel, drainable oil.
What is payload?
The load available for passengers, cargo, and baggage after weight of the pilot, crew, and fuel is deducted from the useful load
What is operational weight empty?
Basic empty weight of an aircraft plus weight of the pilot, crew and all fluids necessary for operation such as engine oil, engine coolant, water, and unusable fuel. Excludes usable fuel and payload.
What is usable fuel?
Fuel available for flight planning.
What is unusable fuel?
Fuel remaining in tanks and fuel lines after all usable fuel has been used. About 2 gallons for our plane.
What is max gross weight?
The maximum authorized weight of the aircraft and all of its equipment as specified in the type certificate data sheet(tcsd) for the aircraft
What is max takeoff weight?
The maximum weight approved for takeoff.
What is max ramp weight?
The maximum weight approved for ground maneuvering, total weight of a loaded aircraft including all fuel. It is greater than the takeoff weight due to the fuel that will be burned during taxi and run-up operations.
Zero fuel weight?
The maximum weight, exclusive of usable fuel.
What’s Passenger weight?
Weight of all passengers
How does weight affect flight performance?
A heavier gross weight results in a longer takeoff roll and shallower climb and a faster touchdown speed and longer landing roll.
Define thrust
Forward force produces by powerplan/propeller
Define drag
A rearward, retarding force caused by disruption of airflow by the wing, propeller, fuselage, other protruding objects
Define lift
The upward force that is produced by dynamic effect of the air acting on the airfoil and acts perpendicular to the flight path.
Define weight.
The combined load of the aircraft itself, the crew, the fuel and the cargo or baggage. Pulls the aircraft downward because of gravity.
Define Angle of Attack
The acute angle between the chord line of an airfoil and the direction of the relative wind
What is relative wind?
Direction of the airflow produced by an object moving thru the air. Relative wind is opposite the aircrafts flight path.
What is bernouli’s principle?
Explains how lift is created
Pressure and velocity are inversely related so airflow over the upper surface of an airfoil causes a reduction in air pressure, inducing lift
What is a stall?
A rapid or sudden loss of lift caused by the separation of airflow from the wing’s surface brought on by exceeding the critical AOA
A stall can occur at any pitch, attitude or airspeed
Define ground effect
Reduction in induced drag due to interference of the ground with airflow around the wing
Exist approximately one wingspan from the ground. Feels like an increase in lift.
What are the two basic types of drag?
Parasite drag-caused by the aircraft’s surface deflecting/ interference with the smooth airflow over the plane. Increases with speed, slows the aircraft down.
Induced drag- byproduct of lift, decreases with speed
What are 3 types of parasite drag?
1.form drag-the drag created because of the shape of a compartment or the aircraft.
2.skin friction drag-caused by air slowing down as it moves across the surface of the aircraft. Rivets, dirt, or anything that makes the surface less smooth adds to this type of drag.
3.interference drag- caused by the intersecting airstreams from different parts of the aircraft.
What is the airspeed at which induced and parasite drag meet?
Vg, glide speed, also known as the lift to drag ratio.
What is p-factor?
when the propeller’s blades experience different loads, resulting in different amounts of lift or thrust. This can happen when the aircraft is at a high angle of attack, such as during takeoff or slow flight. P-factor is why right rudder pressure is applied during takeoff
What is adverse yaw and how is it counteracted?
Adverse yaw is when the nose of the aircraft tends to turn away from intended direction of turn. The adverse yaw is a result of differential drag and slight difference in velocity of the left and the right wings.
The downward deflected aileron produces more lift and drag. This added drag causes the wing to slow down slightly, resulting in the aircraft yawing toward the wing that has experienced more lift and drag.
Application of the rudder is used to counteract adverse yaw.
What causes a spin, when is a spin most likely to occur?
A spin is an aggravated, uncoordinated stall that results in a descending autorotation
A spin is most likely to occur in base to final turn. The aircraft will spin in the direction of the most stalled” wing.
What is the proper spin recovery procedure?
P.A.R.E
P-power idle
A-ailerons neutral
R-opposite rudder, which fight more
E- Elevator forward, briskly
What is wake turbulence? How do you avoid it?
Wingtip vortices are created when an airplane generates lift. As lift is generated, air spills over the wingtips and creates rapidly rotating whirlpools of air called wingtip vortices or wake turbulence. Wingtip vortices are greatest when generating aircraft is heavy, clean, and slow, most commonly encountered during takeoff and landings.
To minimize the chances of flying through another aircrafts wake turbulance:
1.Avoid flying through another aircraft’s flightpath
2.When taking off behind another aircraft, rotate prior to the point at which the preceding aircraft rotated.
3.Avoid following another aircraft on similar flight path at an altitude within 1’000 feet
4.when landing behind another aircraft approach the runway above a preceding aircraft’s path and touch down after the point at which the other aircraft’s wheels contacted the runway.
Define the characteristics of class delta airspace
1.controlled airspace around smaller airports
2.typically surface to 2,500 msl
3.Dashed blue lines with one layer on vfr sectional charts
4.can revert to class echo at night if atc tower is not operable
5.solo student pilots allowed
6.mode c transponder and adsb not required
7.2way radio contact required
8.speed restrictions:200 knots inside
9.vfr basic weather mins:3sm vis, 1000 above, 500 below, 2000 horizontal
Define the characteristics of class echo airspace
1.controlled airspace not classified as a,b,c,d
2.most of airspace over the u.s. is classified echo
3.typically from 1200’ agl to class a, but can begin at surface or 700’ agl
4.may be depicted on vfr sectional chart as dashed magenta line(surface) or faded solid magenta circle(700’ agl) or blue solid faded circle(1,200’ agl)
5.vfr weather minimum requirements:
Below 10,000 msl:basic 3 sm visibility, 1000’ above, 500 below, 2000 horizontal
Above 10,000’ msl:5sm visibility, 1000’ above, 1000’ below, 1sm horizontal of clouds
What are the different types of class echo airspace?
Feetso1450
1.federal airways-airways that are the primary means for routing aircraft operating under ifr.
2.extension to surface- class echo extensions that begin at the surface up to the overlying controlled airspace
3. En-route domestic area- class echo that extends upward from a specified altitude and is used for en-route domestic airspace areas to provide controlled airspace.
4.transition area-class echo beginning at 700’ agl, shown as a thick faded magenta line on vfr sectional charts
5.surface area designated to an airport- class echo beginning at ground surface, show as a dashed magenta line on vfr sectional charts
6.offshore-controls incoming and outgoing international flights, extends 12 nm from the coast
7.14,500 class echo beginning at 14,500 msl unless otherwise depicted.
Define the characteristics of class g airspace.
1.Uncontrolled, low lying airspace
2.extends from surface to the base of overlying class echo
Vfr weather mins:
Above 10,000 msl: 5sm vis, 1000’ below, 1000’ above, 1 mile horizontal of clouds
Below:
Day: 1sm vis, clear of clouds
Night: basic 3sm vis, 1000’ above, 500’ below, 2000’ horizontal of clouds
Define controlled airspace
1.Airspace where air traffic control(atc) services are provided.
2.established to ensure the safe and efficient flow of air traffic. Aircraft operating within controlled airspace are subject to specific regulations and clearance requirements.
3. Within controlled airspace, pilots are required to communicate with atc, adhere to designated routes and altitudes, and obtain clearances for various activities such as takeoffs, landings and changes in direction.
4.Air traffic controllers provide separation services to ensure that aircraft maintain safe distances from each other and assist pilots in navigating through the airspace.
Define uncontrolled airspace
1.Airspace where air traffic control(atc) does not have jurisdiction and services are not provided
2.aircraft operating within uncontrolled airspace have greater freedom and responsibility for their own navigation and separation from other aircraft
3. Uncontrolled airspace is typically found in less congested or remote areas, away from major airports and airways. It may include rural or sparsely populated regions, as well as lower altitudes where air traffic is less dense.
What are the vfr takeoff minimums for controlled and uncontrolled fields?
Controlled field- 3sm ground vis
Uncontrolled field- 1sm ground vis, clear of clouds
What are isogonic lines?
Lines of equal magnetic variation, shown on vfr sectional chart
Define MOA?
Special use airspace.
Military operations area- defined vertical and lateral limits established for the purpose of separating certain military training activities from ifr traffic. Shown as magenta hash on vfr sectional charts. Check sectional chart for times of operation. Altitudes affected, and controlling agency. Vfr pilots should exercise extreme caution when flying through, permission is not required to enter.
Define Cfa?controlled firing area
Special use airspace
Controlled firing area
Areas of ongoing activities that could be hazardous to non-participating aircraft. Ex:artillery fire. Not depicted on vfr sectional charts
Define Prohibited area
Special use airspace
Areas where no civil aircraft is allowed. Shown as blue hash marks on vfr sectional charts. Check sectional for more info.
Define Restricted areas
Special use airspace
Areas of unusual, often invisible, hazards to aircraft(ex: artillery firing, aerial gunnery, or guided missiles) shown as blue hash marks on vfr sectional charts with r-xx. Need permission to enter if area is hot”
Define alert area
Special use airspace
Areas of high volume of pilot training or any unusual type of aerial activity. Pilots should be particularly alert in these areas. No permission is needed to enter. Shown as blue hash on vfr sectional chart with a-xx.
Define warning area
Special use airspace
Airspace extending 3nm outward from the us coastline that contains activity hazardous to non participating aircraft. The purpose is to warn pilots of potential danger. Shown as blue hash marks on vfr sectional chart with w-xx
Define other’’ airspace
Special use airspace
Military training route(mtr), national security area(nsa) temporary flight restriction(tfr), flight restriction zone(frz) wildlife refuge, etc.
What is raim?
Receiver autonomous integrity monitoring. It was developed to assess the integrity of the gps signal. If you get a low raim or a no raim gps is not reliable.
What is maneuvering speed?
Va The speed at which one abrupt full deflection can be performed without over stressing the aircraft or risking structural damage.115-129mph not shown on tachometer
What is Vr?
Rotation speed. 65mph
What is Va?
Maneuvering speed, max speed one abrupt maneuver with no structural damage.115-129mph
What’s Vg?
Best glide speed. 80mph
What’s Vfe?
Max flaps extended speed. 115mph
Top of white line
What’s Vle?
Max landing gear extended. Not available for my plane.
What’s Vlo?
Max speed landing gear can safely be extended or retracted.
What’s Vlo?
Max speed landing gear can safely be extended or retracted.
What’s Vne
Never exceed speed. 171 mph
Red line
What’s Vno?
Max structural cruising speed. 140mph
Top of green line
What’s Vs0?
Power off stall speed landing configuration. 55 mph
(Full flaps, bottom of white line)
What’s vs1?
Minimum controllable airspeed. 55mph
What’s Vs?
Power off stall speed clean configuration. 64 mph
Zero flaps, bottom of green line
What’s vx?
Best angle of climb,74mph. max altitude gain per horizontal distance
What’s vy?
Best rate of climb. 85mph
Max altitude gain per time.
Define IAS?
Indicated airspeed. The direct reading from the airspeed indicator
Define CAS?
Calibrated airspeed. IAS corrected for instrument, position error.
Define TAS
True airspeed. Actual speed through the air. CAS corrected for non-standard temp and pressure.
Define indicated altitude?
Altitude read directly from the altimeter when it is set to the correct, local altimeter setting
Define true altitude
Actual height above mean sea level(msl)
Define Absolute altitude
Actual height above ground level(agl)
Define pressure altitude
Altitude corrected for non-standard pressure, reading on altimeter if set to 29.92” hg standard datum.
Define density altitude
Pressure altitude corrected for non standard temp, the altitude the plane feels like it’s operating based on temperature, pressure and humidity.
What factors affect density altitude?
High to low lookout below
Temperature, humidity, pressure.
Less air density less performance.
What are student pilot limitations?
1.Cannot carry passengers
2. Cannot carry property or passengers for compensation or hire.
3.Cannot fly for compensation or hire
4. Cannot fly in furtherance of business
5. Cannot fly with a surface visibility of less than 3sm during day. 5sm night.
6. Flight must be made with visual reference to the surface.
7. Cannot fly in a manner contrary to any limitations placed on the pilot’s logbook by an authorized instructor.
What does category mean?
the broadest classification of aircraft based on their intended use and operating environment, such as plane, glider, or helicopter.
What does class mean?
A more specific division within a category based on design and performance characteristics, such as single-engine or multi-engine.
What does type mean?
Refers to a specific make and model of an airceaft, such as boeing 737 or piper cherokee
What are the types of medical certificates?
1st class- Airline transport pilots
2nd class- Commercial pilots
3rd class- Private pilots, student pilots
How long is a 3rd class medical valid?
Under 40-60 months till end of month
Over 40- 24 months till end of month
What documents must you carry onboard as PIC?
Pilots license or student pilots license
Government-issued photo ID
Valid medical certificate
Logbook with proper endorsement, if soloing as student.
When does ppl expire?
Never, as long as you remain current vfr takeoff mins. Biannual review and have a valid medical certificate. U can act as PIC
What airplane documents required to be onboard the aircraft?
Supplements21.120
Placards91.9
Airworthiness certificate 21.181
Registration 91.203
Radio license(international)
Operational limits found in poh 91.9
Weight and balance 23.1589
Do you need to take your logbook with you as PIC?
No, only when solo-ing as student pilot
Does an aircraft registration expire?
Yes every 7 years after the last day of the month which it was issued or after a change in ownership. Owner dies, sold from another country.
What is basic med?
Alternative way for pilots to fly without holding faa medical
What are the requirements to fly under basic med?
- Hold a valid drivers license
2.have held a medical certificate after july 14,2006
3.complete physical exam with a state licensed physician - Complete medical education course
What are the operating limitations under basic med?
1.Cannot carry more than 6 passengers or fly an aircraft that can carry more than 7
2.cannot operate any aircraft that has a maximum certified takeoff weight of more than 12,500 lbs.
3. Must operate only under vfr or ifr, within the u.s. under 18,000 msl and cannot exceed 250 knots
4.cannot fly for compensation or hire
5. Pilots must take education course every 24 calendar months.
Medical exam must be completed by aviation medical examiner or state licensed physician every 48 calendar months.
Difference between proficiency and currency?
Proficiency- what is safe, self-determined minimums, do I feel comfortable making this flight?
Currency- what is legal, the minimum faa requirements to be able to fly, can I legally make this flight?
What is required to receive additional endorsements?
1.receive and log both ground and flight training by an authorized instructor in the same type of aircraft.
2.receive a one-time endorsement from an authorized instructor.
What is complex aircraft?
An aircraft containing retractable gear, flaps, controllable pitch propeller.
What is a high performance aircraft?
Aircraft with engine capable of producing more than 200 horsepower
What is an airworthiness certificate?
Faa inspection certificate granted to an aircraft after it has been thoroughly inspected and deemed safe for flight
A valid airworthiness certificate is required onboard for every flight visible to all passengers.
Does an airworthiness certificate expire??
No as long as inspection requirements are met and the aircraft receives the required maintenance
What are the required inspections for an aircraft? How often is each required?
A-airworthiness directives
Urgent or less urgent(within period of time
A-annual/every 12 calendar ms91.409
V-vor/every 30 days/ifronly 91.171
1-100 hour inspection/if for hire91.409b
A-altimeter and pitot static system
Every 24 calendar months91.411
T-transponder/ 24 calendar ms91.413
E- elt every/12 months, 1 hour cumulative use, or 50% of usable battery, unknown use)91.207
Can you fly over an annual inspection?
To fly over an annual inspection, you must obtain a special flight permit issued by the FAA for the purpose of flying the aircraft to a location where the annual inspection can be performed
Can you fly over a 100 hour inspection?
- A 100 hour inspection has a grace period of 10 hours and in those ten hours can only be flown en route to inspection.
- Any excess time used for this purpose must be included in computing the next 100 hours of time in service
3.annual can substitute 100 hour inspection. However, 100 hour inspection cannot substitute an annual inspection.
What’s the difference between a 100-hour inspection and an annual inspection?
1.an annual inspection is required for all aircraft every 12 calendar months
2. A 100-hour inspection is only required for aircraft for hire. A 100-hour inspection cannot take the place of an annual inspection but an annual can take the place of a 100-hour inspection
3. An aircraft maintenance technician(amp) can sign off on an 100-hour inspection but an authorized inspector(ai) must sign off on an annual inspection
What is an airworthiness directive?
1.used to notify aircraft owners of unsafe post- manufacture conditions under which the aircraft may continue to be operated
2. Essentially a recall for an aircraft part that must be fixed for the aircraft to remain airworthy.
What are the two types of airworthiness directives?
Urgent/ requires immediate compliance prior to flight
Non urgent/ requires compliance within a certain period of time
What is a special permit?
1.a special airworthiness certificate authorizing operation of an aircraft that does not currently meet applicable airworthiness requirements but safe for specific flight.
2. Used to allow the aircraft to be flown to a location where repairs, alterations or maintenance can be performed; for delivering or exporting the aircraft. Or for evacuating an aircraft from an area of impending danger
What is preventative maintenance?
Simple or minor preservation operations and the replacement of small standard parts not involving complex assembly operations. You can find a comprehensive list in FAR part 43 appendix A
What are some examples of preventative maintenance?
1.cleaning and greasing landing gear
2.replacing tires, safety belts, fuel lines, batteries, lightbulbs, etc.
3.removing, installing, and repairing landing gear tires
4.replenishing hydraulic fluid.
5.simple fabric patches.
What is an elt? When is an elt not required?
Emergency locator transmitter
1.an elt broadcast distictive signals on designated frequencies and is typically auto activated on impact
2.an elt is not required for scheduled flights by air carriers, training flights within 50 nm of the home airport, agricultural purpose aircraft, and aircraft not equipped to carry more than one passenger
When does an elt have to be inspected?
Every 12 calendar months and replaced or recharged after 1 hour cumulative use or after half of the battery life is used, also if the use is not know like if you find it turned on.
What is an mel?
Minimum equipment lists- document that allows an aircraft to operate safely with some equipment inoperable, as approved by the Federal Aviation Administration (FAA)
Can you fly with inoperative equipment?
Yes, as long as the equipment is not mandatory for flight.
What is the proper procedure for inoperative equipment?
The inoperative equipment item shall be deactivated or removed and an “inoperative” placard must be placed near the appropriate switch, control, and indicator.
If you discovered the landing light was inoperative prior to a flight, what would you do?
If the aircraft is operated for hire, the flight cannot be conducted at night. The landing light must be deactivated by pulling the breaker, and placarded as inoperative”
If the aircraft is not operated for hire, a vfr flight at night can still be conducted
A daytime flight can still be conducted.
If you discovered the altimeter was inoperative prior to a flight, what would you do?
Cancel the flight because the aircraft does not meet the minimum equipment requirement for flight
If you discovered the aircraft’s heat system was inoperative prior to flight, what would you do?
The equipment must be deactivated by pulling the breaker and placarded as “inoperative”
The flight can still be conducted
What is a prognostic chart?(prog chart)
forecast map showing the state of the atmosphere at a future time. Issued 4x per day, 12-24 hour validity, consists of pressure, fronts, precipitation, vfr, mvfr, ifr conditions, turbulence, freezing levels
What is a surface analysis chart?
1.analysis of current surface weather
2. Issued every 3 hours
3. Consists of high/low pressure areas, fronts, isobars, temperatures, dew points, wind direction and speed
What is weather depiction chart?
1.A computer generated report based on metars and other surface observations that give a broad overview of flying conditions at that time (vfr/ifr, fronts, throughs, squall lines)
2.generated by a computer every 3 hours
3. Designed to be used for flight planning by giving an overall picture of the weather
What is the difference between atis/asos/awos?
Atis- automated terminal information service. Recording of the local weather conditions and other pertinent information broadcast on local frequency in a looped format. Updated every hour by a human and given a unique identifier code.
Asos/awos- automated surface/weather observing system. Continuous broadcast of weather conditions by a computer. Reports include date, time, wind direction and speed, visibility, sky condition, temperature, dew point, altimeter setting
What is an airmet?(wa)
Airman’s meteorlogical information
1.unscheduled in flight Advisory of significant weather phenomena hazardous to light aircraft.
Ex:moderate icing, turbulence, surface winds of 30+ knots
2.valid for 6-hour period with updates as needed
What are the requirements to become a private pilot?
61.103
1.Be at least 17 years of age
2.Be able to read, write, speak, and understand english.
3.Hold a US student pilot certificate
4. Hold at least a third- class medical certificate
5. Receive and log ground and flight training and receive proper endorsements by an authorized instructor.
6.pass the required knowledge and practical test.
7.meet the applicable aeronautical experience requirements from FAR 61.109
How do you remain current as a private pilot?
Complete a biannual flight review with an authorized instructor within the preceding 24 calendar months. Can be substituted by a check ride for a rating.
Also there is day and night vfr currencys witch are 3 take offs and landings within the preceding 90 days. They must be to a complete stop at night.
What are the currency requirements for carrying passengers?
- Within the preceding 90 days, log 3 takeoffs and landings in the same category, class, and type of aircraft.
- If carrying passengers at night, takeoffs and landings must be made to a full stop and at night.
What is the definition for night” landings?
Night” is one hour after sunset to one hour before sunrise.
What is the definition of night” for flight time?
Night” is the time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the air almanac, converted to local time.
What are the privileges of a private pilot?
1.can act as pic and carry passengers if passengers currency requirements are met.
2. Can fly for charitable event.
3.Can fly for search and rescue
4. Can act as an aircraft salesman with 200+ hours of pic experience
5. Can tow a glider with proper training and endorsement and over 100 hours of pic
What are the limitations of a private pilot?
- Cannot act as pic for compensation or hire.
2.5 cannot carry passengers or property for compensation or hire - Cannot pay less than pro-rata share of the operating expenses involving only fuel, oil, airport expenditures, or rental fees.
- Can only fly in vfr weather conditions
61.117 cannot be sic. I cannot fly a plane that requires 2 pilots
What are the three types of airmets?
What does each report?
1.sierra-ifr conditions and mountain obscuration
2.tango- moderate turbulance, strong surface winds 30+ knots, and/or low-level wind shear
3. Zulu- moderate icing and freezing levels
What is a sigmet?(ws)
Significant meteorological information
1.an unscheduled inflight advisory of non-convective weather that is potentially hazardous to all aircraft. Usually covers 3,000 square miles.
2. Usually Reports weather forecast that are not associated with thunderstorms including severe icing, extreme turbulance, dust storms, and sandstorms, volcanic ash.
3. Valid for 4 hours, unless related to a hurricane, in which case it is valid for 6 hours
What is a convective sigmet?(wst)
1.an unscheduled inflight weather advisory issued for hazardous convective weather that affects the safety of all aircraft.
2. Issued for severe thunderstorms with surface winds greater than 50 knots, hail larger than 3/4 inch in diameter. Tornadoes, and embedded thunderstorms, line of thunderstorms.
3. Issued 55 minutes past the hour and valid for 2 hours
4. Special convective sigmet’s issued as needed.
Which is worse airmet or sigmet?
A sigmet is always worse as it advises all aircraft of extreme conditions
Airmet only advises light aircraft.
What is a metar?
Meteorological aerodrome report
1. An observation of current surface weather reported in a standard international format
2. Issued hourly at 55 minutes past the hour or anytime special weather events occur(speci)
Ex: metar kggg 161753z auto 14021g26kt 3/4 sm +trsa
What is a taf?
Terminal aerodrome forecast
Issued 4x per day, valid 24 hours, Reports forecasted winds, visibility, sky conditions and weather in vicinity of airport5nm
What is a pirep?
What are the two types?
Reports of actual in flight conditions issued by pilots.
1. The two types are
1.ua- routine report
2.uua- urgent report
2. Reports include location, time, altitude, sky cover, visibility, observed weather, cloud layer, temperature, wind, possible turbulence, and potential icing.
Pireps are available from atc, fss, aviation weather.gov
What is the cause of all weather?
Uneven heating of the earths surface
What are the three main layers of the atmosphere?
Troposphere, tropopause, stratosphere
What is wind the result of?
Differences in pressure in The atmosphere.
What is wind shear?
a change in wind speed and/or direction over a short distance
What are the characteristics of stable air?
1.calm
2.stratiform clouds
3.smooth air
4. Steady or continuous precipitation
5. Poor surface visibility
What are the characteristics of unstable air?
1.cumulous clouds, or clouds with vertical development
2. Showery precipitation
3. Turbulence
4. Good surface visibility
5. Strong surface winds
What is an airmass?
a large body of air with a relatively uniform temperature and humidity that covers thousands of square miles or more. Air masses take on the characteristics of their source region, which can be polar regions, cold oceans, tropical oceans, or deserts. The longer an air mass stays over its source region, the more likely it is to adopt the properties of the surface below
What is a front?
The transition zone between two types of air masses
Define cold front.
1.Cold-blue triangles- cold mass(stable air) advances under and replaces body of warmer air(fast moving, blue triangles on weather chart)
2.Ahead of cold front, towering cumulus clouds and cumulonimbus clouds may form. Severe weather is possible and may include rapid development of heavy rain showers, lightning, hail, and/or tornadoes. Eventually, good visibility prevails once the cold air dominates the area.
Define warm front
1.Warm front-red circles-warm mass (unstable air) advances over and replaces body of colder air(slow moving, red circles on weather chart)
2. Light to moderate precipitation in the form of rain, sleet, snow, or drizzle often along with poor visibility.
Define stationary front.
- Stationary front-Red circles and blue triangles- when the forces of two fronts are relatively equal and the masses remain stationary(alternating red circles/blue triangles on weather chart)
- Mix of cold and warm front conditions
Define Occluded front
1.Purple circles and triangles- fast moving cold front catches up to a slow moving warm front(purple alternating circle/triangle on weather chart)
2. Mix of cold and warm front conditions
What is a trough?
Elongated area of low pressure, rising air
What is a ridge?
Elongated area of high pressure, descending air
What is an isobar?
Solid lines on a weather chart depicting lines of equal pressure. Lines closer together indicate steep pressure gradient and strong winds
What are the general characteristics of a low pressure area?
- Counter-clockwise inward rotation with rising air
- Cyclonic
3.poor visibility - Rain, fog, thunderstorms, cloudiness
What are the general characteristics of a high pressure area?
1.clockwise outward rotation with descending air
2.dry
3.good weather clear skies
Define ceiling
Lowest layer of broken or overcast clouds
What causes turbulence?
atmospheric pressure, jet streams, air around mountains, cold or warm weather fronts, and thunderstorms
What three ingredients must be present for a thunderstorm to develop?
Sufficient water vapor, unstable lapse rate and lifting action
Define lapse rate. What is the standard lapse rate?
- Lapse rate is the change in temperature over altitude.
- The standard temperature lapse rate is a temperature decrease of approximately 3.5 degrees farenheit or 2 degrees celsius per 1000’ in the troposphere.
What are the three stages of a thunderstorm?
Cumulus- initial updraft of air
Mature- falling precipitation , convective activity(most turbulent stage)
Clouds cannot hold the moisture and rain begins
Dissipating- large downdrafts as the storm rains itself out
Stay 20 nm away from thunderstorms because of hail
What is a microburst?
An extreme version of wind shear, characterized by an extreme downdraft up to 6’000 feet per minute
Very dangerous to all pilots and all aircraft.
What is a squall line?
A narrow band of active thunderstorms, often forming on or ahead of a cold front.
What is an embedded thunderstorm?
A thunderstorm hidden” in the clouds
When vertical clouds can be obscured by other cloud formations and are not always visible from the ground or while in flight.
