FAA Aircraft Dispatcher (ADX) flashcards

Requires an FAA-approved program using holdover time tables to ensure a clean aircraft prior to takeoff in icing conditions.

• Holdover time varies with precipitation type/intensity and OAT
• Program includes pre-takeoff contamination checks
• Supports compliance with the clean aircraft concept

Memory trick: Colder and heavier snow shrinks your holdover clock.

The force that drives wind from high to low pressure, proportional to the rate of pressure change over distance shown by isobar spacing.

• Close isobars = strong gradient = strong wind
• Wide isobars = weak gradient = light wind
• Wind speed is proportional to gradient, not pressure value itself

Memory trick: Tight lines, tight winds — squeeze the isobars, squeeze out speed.

The ceiling is the height above ground level of the lowest layer of clouds reported as broken (BKN), overcast (OVC), or vertical visibility (VV), not including scattered (SCT) or few (FEW) layers.

• Scattered (SCT) and Few (FEW) layers do not create a ceiling
• Broken (BKN) covers 5/8 to 7/8 of the sky
• Overcast (OVC) covers the entire sky

Memory trick: 'Ceiling starts when the Broken begins' — SCT doesn't count, BKN and OVC do.

NOTAMs are categorized by type based on content: NOTAM (D) covers airport/facility conditions; FDC NOTAMs cover regulatory and procedural changes.

• NOTAM (D): runway/taxiway closures, lighting, obstructions
• FDC NOTAM: TFRs, approach procedure amendments, chart changes
• Both are distributed through the NOTAM system but serve different purposes

Memory trick: D is for the Dirt on the runway — facility stuff; FDC is for the Federal rules.

The headwind or tailwind component equals wind speed multiplied by the cosine of the angle between the wind and the aircraft's course.

• Headwind component = wind speed × cos(angle off nose)
• Ground speed = TAS − headwind (or + tailwind) component
• At 90° off the nose, wind is pure crosswind with no speed effect

Memory trick: 'Cosine cuts the wind down to size.'

A boundary where warm air actively replaces retreating cold air, characterized by a shallow slope and widespread stratiform cloud and precipitation ahead of the surface position.

• Slope roughly 1:100 to 1:300
• Produces cirrostratus through nimbostratus progression
• Precipitation and reduced visibility can extend 200-300 miles ahead of the surface front

Memory trick: Warm fronts are 'gentle giants' — slow, wide, and soaking everything ahead of them.

When weight is shifted within an aircraft, the CG shift distance equals (weight moved × distance moved) divided by total aircraft weight.

• Formula: CG shift = (weight shifted × distance shifted) ÷ total weight
• Direction of CG shift matches direction weight was moved
• Used for load shifts, not for adding/removing weight

Memory trick: 'Move the load, share the shift — divide by the whole to get the drift.'

Contingency fuel is additional fuel, typically 5% of trip fuel, carried to cover unforeseen factors that could affect fuel consumption to the destination.

• Standard value: 5% of trip fuel
• Covers unplanned routing, wind, or ATC delays
• One component among taxi, trip, alternate, and reserve fuel

Memory trick: '5% for surprises' — contingency covers the unexpected.

Sets minimum number of passenger-compartment hand fire extinguishers based on seating capacity.

• 7-30 seats = 1 extinguisher
• 31-60 seats = 2 extinguishers
• 61-200 seats = 3 extinguishers (increasing further for larger cabins)

Memory trick: Bigger cabin, more red bottles — seat brackets set the extinguisher count.

A SIGMET issued for volcanic eruptions producing ash clouds hazardous to aircraft, valid for up to 6 hours.

• Valid for 6 hours (vs. 4 hours for standard non-convective SIGMETs)
• Volcanic ash can cause jet engine flameout and severe airframe/windscreen damage
• Issued regardless of location, since ash can spread far from the eruption site

Memory trick: 'Volcanoes and hurricanes get extra time'—6 hours, not 4.

Regulation establishing that the PIC and aircraft dispatcher share joint responsibility for preflight planning, delay, and dispatch of domestic and flag flights.

• Applies to domestic and flag operations
• PIC and dispatcher must both agree flight can be safely conducted
• Certificate holder retains overall operational control responsibility

Memory trick: Two signatures, one safe flight: PIC + Dispatcher

Air masses are classified by source region temperature (arctic, polar, tropical) and moisture content (maritime, continental).

• cP: cold, dry, over land
• mT: warm, moist, over tropical ocean
• cT: hot, dry, over tropical land
• mP: cool, moist, over polar ocean

Memory trick: Letters tell moisture (m/c) then temperature (T/P) — 'mT = Muggy Tropics'.

A legal document issued to each certificate holder detailing authorized aircraft, routes, airports, and operational limitations under Part 119/121.

• Issued under Part 119 alongside the operating certificate
• Specifies authorized aircraft, routes, and airports
• Legally binding; must be kept current and available

Memory trick: "OpSpecs = the operator's rulebook for where and what it can fly."

Regulation requiring turbine-powered Part 121 airplanes to carry airborne weather radar on routes where thunderstorms may occur.

• Applies to turbine-powered airplanes
• Triggered by forecast/expected thunderstorms along the route
• Radar must be approved and operable for dispatch

Memory trick: Turbines and thunderstorms mean radar is a must.

The ratio, expressed as a percentage, of the actual water vapor content of the air to the maximum amount the air could hold at that temperature.

• 100% relative humidity means the air is saturated
• Relative humidity changes with temperature even if moisture content stays constant
• Warming air lowers relative humidity; cooling raises it toward saturation

Memory trick: RH is a percentage of a 'full glass' of water vapor capacity.

A downslope wind caused by cold, dense air draining from higher terrain into valleys, most common on clear nights with light gradient winds.

• Driven by radiational cooling and gravity
• Occurs mainly at night in mountain/valley terrain
• Opposite of foehn wind, which is warm and adiabatically heated

Memory trick: Katabatic = 'cold air cascades' downhill after dark.

An ATC advisory made by a pilot when fuel state is such that no delay can be accepted, without declaring an emergency or guaranteeing priority handling.

• Does NOT guarantee priority handling from ATC
• Distinct from declaring a fuel emergency (which does require priority)
• Alerts ATC that a subsequent delay could result in an emergency

Memory trick: 'Minimum fuel is a heads-up, not a 911 call'

The boundary layer separating the troposphere from the stratosphere, marked by a sharp change in the temperature lapse rate; its height varies with latitude and season.

• Higher (~55,000 ft) and warmer at the equator; lower (~25,000-30,000 ft) and colder at the poles
• Marked by transition from decreasing to isothermal/increasing temperature with height
• Closely associated with the position of the jet stream

Memory trick: Tropopause = the 'ceiling' of weather, where temperature stops falling

14 CFR 91.185(c)(1) establishes a priority order for determining the route to fly after a two-way radio failure while IFR.

• A = Assigned route in last ATC clearance
• V = Vectored — direct to the fix/route/airway specified when the vector was given
• E = Expected route per further clearance information
• F = Filed flight plan route if none of the above apply

Memory trick: AVEF: 'A Very Endless Flight' — Assigned, Vectored, Expected, Filed

VORs are classified (T, L, H) with standard service volumes defining usable signal range at various altitude bands; High-altitude VORs have the largest overall coverage.

• Terminal (T): 25 NM, 1,000–12,000 ft
• Low (L): 40 NM, 1,000–18,000 ft
• High (H): 40 NM to 14,500 ft, 100 NM to 18,000 ft, 130 NM to 45,000 ft, 100 NM to 60,000 ft

Memory trick: 'High goes far, then shrinks near the top' — H-class range expands then contracts above 45,000 ft.

The critical speed during takeoff roll at which the decision to continue or reject the takeoff must be made.

• Balances accelerate-stop and accelerate-go distances
• Below V1: reject; at/above V1: continue takeoff
• Determined by weight, runway, wind, and obstacle data

Memory trick: V1 = 'the point of no return' on the runway.

Requires documentation of weight, CG, and balance data before dispatch to verify the airplane is within limits.

• Includes airplane weight and max allowable weight
• Includes CG limits and actual loaded CG
• Signed by preparer, does not include passenger seating

Memory trick: "Weigh it, Limit it, Balance it, Sign it" — but never seat-map it.

True airspeed at a given Mach number equals the Mach number multiplied by the local speed of sound, which varies with outside air temperature.

• TAS = Mach × local speed of sound
• Speed of sound decreases with colder temperatures (higher altitude)
• Mach number is used for high-speed cruise performance and buffet margins

Memory trick: Mach × sound speed = true airspeed — like a percentage of the local 'sound limit'.

ETOPS diversion time is the maximum time, in minutes, that a twin-engine aircraft may operate from an adequate alternate airport based on one-engine-inoperative cruise speed in still air.

• Common authorizations: 60, 120, 180, 207, 240 minutes
• Based on OEI cruise speed, not normal cruise speed
• Defines the ETOPS area of operation on a route

Memory trick: '180 means never more than 3 hours from safety on one engine.'

A procedure allowing independent radar-monitored ILS approaches to closely spaced parallel runways, requiring at least 4,300 ft centerline separation and use of an NTZ.

• Minimum 4,300 ft runway centerline spacing (standard case)
• No Transgression Zone (NTZ) monitored by radar between final approach courses
• Requires precision runway monitor for closer spacing in some cases

Memory trick: '4,300 feet — the safety gap between two jets landing side by side.'

Published climb gradients (ft/NM) must be converted to a rate of climb (fpm) based on groundspeed to verify aircraft performance compliance with departure procedures.

• Formula: ROC (fpm) = (gradient ft/NM × groundspeed kt) ÷ 60
• Standard minimum obstacle clearance gradient is 200 ft/NM
• Higher published gradients override the 200 ft/NM standard when obstacles require it
• Groundspeed, not airspeed, is used in the calculation

Memory trick: 'Gradient times speed, divide by sixty' — the standard performance formula.

When actual air temperature is colder than standard, true altitude is lower than indicated altitude because cold air is denser and pressure levels are compressed closer together.

• Rule: 'hot high, cold low, look out below'
• Altimeter settings correct for pressure, not temperature
• Large temperature deviations require published cold-weather corrections, especially near terrain

Memory trick: 'Cold, low, look out below' — cold air shrinks your safety cushion.

Pressure altitude corrected for nonstandard temperature; represents the altitude the aircraft 'feels' it is performing at.

• High temperature and/or high elevation increase density altitude
• Higher density altitude = degraded engine, propeller, and aerodynamic performance
• Critical factor in takeoff/landing performance planning at hot, high airports

Memory trick: Hot and High means the plane can't Fly (as well)

When two-way radio communications fail in IFR conditions, the pilot must fly the highest of the last assigned altitude, the MEA, or the altitude expected in a further clearance.

• Applies per route segment
• Compare three altitudes, fly the highest
• Route flown is per assigned, vectored, expected, or filed route in that priority order

Memory trick: MEA, Assigned, Expected — always climb to the HIGHEST

Prohibition on takeoff with frost, ice, or snow adhering to critical aerodynamic and engine surfaces.

• Applies to wings, control surfaces, propellers, engine inlets
• Requires ground deicing/anti-icing when contamination present
• Holdover time tables used to determine deicing effectiveness

Memory trick: Clean wings, clean tail, clean engines — or you don't fly.

BECMG indicates a gradual and permanent change in forecast conditions expected within the specified time period, after which the new condition prevails.

• Contrasts with TEMPO (temporary) and PROB (probability)
• Time range shows when transition occurs, e.g., 1416 = 1400Z-1600Z
• New conditions are expected to persist after the transition window

Memory trick: BECMG = 'Becoming' a new normal — the change sticks around.

The airspace within 30 NM of a Class B primary airport, surface to 10,000 ft MSL, requiring both Mode C transponder and ADS-B Out equipment per 91.215/91.225.

• 30 NM radius from Class B primary airport
• Surface to 10,000 ft MSL
• Both altitude-encoding transponder and ADS-B Out required

Memory trick: '30 miles, 10,000 feet — bring your beacon and your broadcast.'

A domestic Part 121 provision allowing dispatch without an alternate when forecast weather is well above minimums for 1 hour before/after ETA.

• 1 hour before to 1 hour after ETA window
• Ceiling at least 2,000 feet above airport elevation
• Visibility at least 3 statute miles
• Applies under 14 CFR 121.619 for domestic operations

Memory trick: 1 hour, 2 thousand feet, 3 miles — count up 1-2-3

Magnetic course is derived from true course by applying magnetic variation: subtract easterly variation, add westerly variation.

• East is least (subtract easterly variation)
• West is best (add westerly variation)
• Variation values come from isogonic lines on charts

Memory trick: East is least, West is best — apply variation to get your magnetic course.

An FAA-approved document that authorizes dispatch of an aircraft with specific inoperative instruments or equipment under defined conditions.

• Approved as part of the operator's operations specifications
• Specifies conditions, limitations, and placard requirements for each item
• Maintenance log entries are still required to document the discrepancy

Memory trick: 'Missing but Managed' — MEL lets you fly with listed gaps

Turbulence caused by the disruption of smooth airflow as wind passes over irregular terrain, buildings, or other obstacles, most common at low altitudes with strong winds.

• Requires both strong wind and rough/irregular terrain
• Produces low-level eddies and gusty, choppy turbulence
• Common in mountainous or hilly terrain with strong surface winds

Memory trick: Mechanical = wind Mashed by terrain into eddies

An ILS marker beacon located about 3,500 feet from the runway threshold that approximates the CAT I decision height.

• Amber light, 1300 Hz tone, alternating dot-dash
• Located near DH on CAT I ILS
• Complements outer and inner markers along the approach course

Memory trick: 'Blue is far, Amber is near, White is where you flare'

Airplanes with more than 60 passenger seats must carry one megaphone; airplanes with more than 99 passenger seats must carry two, located at the most forward and most rearward points in the cabin.

• >60 seats = 1 megaphone
• >99 seats = 2 megaphones (forward & aft)
• Independent of PA system installation

Memory trick: 'Sixty for one, ninety-nine for two — front and back will do.'

A small-scale, intense downdraft that spreads out horizontally upon hitting the ground, producing rapid and severe changes in wind speed and direction over a very short time and distance.

• Diameter typically less than 2.5 nautical miles
• Lifespan usually 5-15 minutes
• Can produce headwind-to-tailwind shear exceeding 45 knots, extremely hazardous on approach/departure

Memory trick: Microburst = a bucket of air dumped straight down, splashing outward fast and hard.

A rule of thumb used to estimate the height of cumuliform cloud bases using the surface temperature-dewpoint spread.

• Formula: cloud base (ft AGL) = spread (°F) × 400
• Metric equivalent: spread (°C) × 1,000 / 2.5
• Applies best to convective (cumulus) cloud formation, not stratiform layers

Memory trick: 'Spread times 400 gets you off the ground' (in feet AGL).

Specific four-digit transponder codes alert ATC to specific situations without voice communication.

• 7500 = hijacking
• 7600 = lost communications
• 7700 = general emergency

Memory trick: 7-5-6-7: Hijack, Lost comm, Emergency (climbing severity)

Regulates conditions under which cargo may be carried in the passenger cabin without compromising safety or emergency egress.

• Cargo must not block aisles or emergency exits
• Must be secured to prevent shifting or restricting occupants
• Must not interfere with emergency equipment access

Memory trick: Boxes may ride in back, but never in front of the exit door.

Airplanes with more than 19 passenger seats must have a public address system, independent of the interphone, audible throughout the cabin including lavatories and flight attendant seats.

• Threshold: more than 19 passenger seats
• Must be independent of crewmember interphone
• Must reach all passenger seats, lavatories, and flight attendant stations

Memory trick: 'Nineteen's the number — PA turns on louder.'

Requires turbine-powered Part 121 airplanes with 10 or more passenger seats to carry a ground proximity warning system with terrain awareness.

• Applies regardless of specific route terrain
• Provides warnings for excessive descent rate, terrain closure, etc.
• Distinct equipment from weather radar and TCAS

Memory trick: Ten seats or more, GPWS keeps you off the mountain floor.

The altitude at which a rising, unsaturated air parcel cools to its dew point, forming the base of a cumulus cloud.

• Temperature falls at dry adiabatic rate (~3°C/1,000 ft)
• Dew point falls more slowly (~0.5°C/1,000 ft)
• LCL height = spread ÷ convergence rate ×1,000 ft

Memory trick: Spread ÷ 2.5 ×1000 = where the cloud base begins.

Equipment required aboard Part 121 aircraft operating more than 50 NM from the nearest shoreline.

• Triggered at more than 50 NM from shore
• Requires life rafts sized for all occupants
• Also requires life preservers and pyrotechnic signaling devices

Memory trick: Fifty miles from shore, bring rafts, vests, and flares galore.

High-altitude airways designated with a 'J' prefix, existing at and above 18,000 feet MSL up to FL450, based on VOR/VORTAC navigation aids.

• J-routes = high-altitude, VOR/VORTAC based, 18,000 ft MSL to FL450
• V-routes (Victor airways) = low-altitude, below 18,000 ft MSL
• Q-routes = RNAV high-altitude routes
• T-routes = RNAV low-altitude routes

Memory trick: 'J for Jet, up high, VOR guide'

Dispatchers must verify that an aircraft's single-engine service ceiling allows safe terrain clearance along the entire route in the event of an engine failure, planning escape routes or weight reductions as needed.

• Compares single-engine ceiling to route MEA/obstacles
• May require an engine-out escape route over lower terrain
• Directly affects maximum allowable takeoff weight on mountainous routes

Memory trick: One engine down, terrain still counts — plan the escape.

A SIGMET is issued for weather phenomena significant to the safety of all aircraft, including severe icing, severe turbulence, dust/sandstorms with visibility below 3SM, and volcanic ash, distinct from AIRMETs which address hazards primarily affecting smaller aircraft.

• Valid for up to 4 hours (6 hours for hurricane-related SIGMETs)
• Covers severe or greater turbulence and icing, unlike AIRMET's moderate threshold
• Unscheduled and issued as needed when criteria are met

Memory trick: SIGMET = 'Significant for everyone', AIRMET = 'Advisory mostly for the little guys'.

An additional ATC service providing traffic advisories to VFR aircraft on a workload-permitting basis, without providing separation or relieving pilot responsibility for collision avoidance.

• Provided workload permitting, not guaranteed
• Does not provide IFR-level separation
• Pilot remains responsible for see-and-avoid
• Either the controller or pilot may terminate the service at any time

Memory trick: 'Following is a favor, not a guarantee' — ATC helps when they can, but you still watch the sky.

14 CFR 91.179 assigns IFR cruising altitudes based on magnetic course: odd thousands for 0°–179°, even thousands for 180°–359°.

• Applies above 3,000 ft AGL under IFR
• 0°–179° = odd thousands (e.g., 9,000, 11,000)
• 180°–359° = even thousands (e.g., 8,000, 10,000)

Memory trick: 'Odd East, Even West' — think of the sun rising odd in the East.

Fog that forms over land on clear nights with light winds due to radiational cooling of the surface, which cools the adjacent moist air to saturation.

• Requires clear skies for maximum radiational cooling
• Requires light or calm winds (too much wind prevents fog, but some mixing helps spread it)
• Typically forms in valleys and low-lying areas, dissipates after sunrise

Memory trick: 'Radiation fog needs a clear, calm, cool night' to let heat radiate away.

Maximum payload is the lesser of the MZFW-limited payload (MZFW − OEW) or the MTOW-limited payload (MTOW − OEW − fuel required).

• ZFW = OEW + Payload, must not exceed MZFW
• TOW = ZFW + Fuel, must not exceed MTOW
• The most restrictive limit determines maximum payload

Memory trick: 'Zero fuel first, takeoff second' — check both, use the smaller number.

Regulation requiring certificate holders to maintain a communication system that continuously monitors the progress of each en route flight.

• Requires continuous monitoring of flight progress
• Relies on company communication systems, not ATC radar
• Supports coordination between dispatcher and PIC for operational control

Memory trick: 'Never lose sight' — dispatch keeps constant watch

Rule requiring PIC to notify dispatch or ground radio promptly after an engine failure/shutdown and land at nearest suitable airport if needed.

• PIC must notify dispatcher/ground station ASAP
• Must state nature of failure and decision made
• Must land at nearest suitable airport if safety requires it

Memory trick: Engine quits? Call it in, then land at the nearest safe spot.

Runway Visual Range (RVR) in feet can be approximately converted to statute mile visibility using a standard FAA conversion table for flight planning and approach minimums.

• RVR 1600 ft ≈ 1/4 SM
• RVR 2400 ft ≈ 1/2 SM
• RVR 4000 ft ≈ 3/4 SM
• RVR 5000 ft ≈ 1 SM

Memory trick: '16-24-40-50-60 → 1/4-1/2-3/4-1-1&1/4' — count up by quarters as RVR climbs.

Higher density altitude (from high temperature, high elevation, or low pressure) reduces air density, decreasing engine power, propeller/wing efficiency, and increasing takeoff distance.

• Density altitude = pressure altitude corrected for nonstandard temperature
• High density altitude reduces engine thrust and lift
• Takeoff distance increases as density altitude increases

Memory trick: 'Hot and high, harder to fly.'

A rapid change in wind speed and/or direction over a short distance near the surface, often caused by temperature inversions, frontal boundaries, or thunderstorm outflow, posing a hazard during takeoff and landing.

• Commonly caused by nocturnal temperature inversions with strong wind gradients aloft
• Also caused by thunderstorm gust fronts/microbursts and frontal passages
• Detected using LLWAS (Low-Level Wind Shear Alert System) at equipped airports

Memory trick: 'Inversion + wind change = Shear on approach, watch your airspeed disappear!'

Controlled airspace around the busiest airports requiring specific ATC clearance before VFR entry, in addition to radio and equipment requirements.

• Clearance phrase: 'cleared into Class Bravo airspace'
• Mode C transponder and ADS-B Out required
• Some primary airports require at least a private pilot certificate to operate

Memory trick: 'Bravo means Big clearance, Big equipment' — must be cleared in, transponder on

Regulation limiting scheduled flight time for domestic Part 121 pilots based on crew size and rest facilities.

• 8 hours max for 2-pilot unaugmented crew in 24 hrs
• 100 hours per calendar month, 1,000 hours per calendar year limits also apply
• Augmented crews allow longer flight time with rest facilities

Memory trick: Two pilots, eight hours — no more without a rest, no less.