Cheat sheet

Medical certificate duration, 61.23(d)

Age is fixed at the date of the examination, not the date of the flight. A pilot who was 39 at the exam keeps 60 calendar months even after turning 40.

A first- or second-class medical does not become worthless when its higher privileges lapse: it keeps serving third-class (private pilot) privileges for the full 60 or 24 months.

Expiry is the end of the last day of the Nth month after the month of the exam, so the day of the month never matters.

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BasicMed, 61.23(c)(3) and 61.113(i)

The two intervals are deliberately swapped in the distractors: the course is the short one (24), the physician exam is the long one (48).

12,500 is a weight in pounds, not an altitude in feet. The altitude limit is 18,000 ft MSL.

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Flight review, 61.56

This is a requirement to act as pilot in command. The private pilot certificate itself never expires.

A practical test or proficiency check passed in the period, or a phase of the WINGS program, substitutes for the review.

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Passenger currency by day, 61.57(a)

Touch-and-go landings count for the day rule in a nosewheel airplane. They do not count in a tailwheel airplane, and they never count at night.

90 days is a rolling day count, not calendar months.

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Passenger currency at night, 61.57(b)

Three different night periods are tested against each other: sunset to sunrise is when position lights are required (91.209), end of evening civil twilight to beginning of morning civil twilight is night for logging (1.1), and 1 hour after sunset to 1 hour before sunrise is night passenger currency.

All three landings must be full stop, not just one.

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VFR fuel reserve, 91.151

GPH

fuel consumption in gallons per hour at cruise

Reverse the day and night figures and the answer is always on the list. 45 minutes is also the IFR reserve, which is why it looks plausible for a VFR day flight.

The reserve is fuel beyond the first point of intended landing, computed at normal cruise, not at the approach or reserve power setting.

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Supplemental oxygen, 91.211(a)

The 30-minute grace period belongs only to the 12,500 to 14,000 band. Above 14,000 there is no grace period.

Above 15,000 passengers must be provided oxygen, not required to use it. Only the required minimum flight crew must use it.

Every altitude is cabin pressure altitude, which in an unpressurized airplane equals the flight altitude.

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VFR cruising altitudes, 91.159

The rule keys on magnetic course, not magnetic heading, so the wind correction angle is irrelevant.

It applies only more than 3,000 ft AGL. Below that, any altitude is legal.

Odd or even thousands without the extra 500 ft are the IFR altitudes, and they are always offered.

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Speed limits, 91.117

Inside Class B the limit is the general 250 KIAS. The 200-knot limit is for the airspace underneath it and for VFR corridors through it. 91.117(b) says so explicitly.

The Class C and D 200-knot limit has two qualifiers that must both be met: at or below 2,500 ft above the surface and within 4 NM of the primary airport.

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Minimum safe altitudes, 91.119

Over a congested area it is 1,000 ft above the highest obstacle, not 1,000 ft AGL, and the radius is 2,000 ft horizontally, not an altitude.

Over open water or sparsely populated areas there is no altitude floor at all, only a 500 ft standoff distance from people and objects.

Inspection and test intervals

ELT batteries are not on a calendar interval: replace or recharge after more than 1 cumulative hour of transmitter use, or when 50 percent of the useful life has expired.

A calendar month interval runs to the end of the last day of that month, so an annual signed off 12 July is good through 31 July of the next year.

The 100-hour interval applies only to carrying persons for hire or giving flight instruction for hire, never to personal flying.

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NTSB reporting, 830.15

Immediate notification of the nearest NTSB office by the most expeditious means is the separate 830.5 duty. The 10-day figure is the written report, not the notification.

The 48-hour figure belongs to the report a pilot given priority by ATC files with the facility manager on request under 91.123(d).

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Class B

Clear of clouds, because ATC separates everything inside Class B. It is the only controlled airspace with no cloud clearance distances.

3 miles and clear of clouds appears in no other row: pairing 3 miles with the standard 500/1,000/2,000 is the Class C, D and low Class E line.

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Class C, Class D and Class E below 10,000 ft MSL

This is the row to memorise first: it covers three classes of airspace and is the reference everything else is measured against.

Class D tops out at 2,500 ft above the airport elevation, so the at-or-above-10,000 row can never apply to it.

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At or above 10,000 ft MSL

The horizontal clearance changes units: 1 statute mile, not 1,000 feet. Reading 1,000 as the horizontal figure is the built-in trap.

In Class G this row applies only when the airplane is both at or above 10,000 ft MSL and more than 1,200 ft above the surface.

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Class G, 1,200 ft or less above the surface

The band is measured above the surface regardless of MSL altitude, so it follows terrain rather than a chart altitude.

Night in this band jumps straight to the full 3 miles and the standard cloud clearances: there is no 1-mile night rule except the traffic-pattern exception of 91.155(b).

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Class G, more than 1,200 ft above the surface but below 10,000 ft MSL

1 statute mile survives the climb through 1,200 ft AGL by day, but the cloud clearances do not: clear of clouds is replaced by 500/1,000/2,000.

Read the question for both numbers: height above the surface decides the row, MSL altitude decides whether the 10,000 ft rule takes over.

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Surface areas and special VFR

Special VFR must be requested by the pilot; ATC never offers it unprompted, and it is not available at night to a pilot without an instrument rating and an instrument-equipped airplane.

The 1-mile special VFR figure is the visibility the clearance relieves, so it is the wrong answer to any basic-VFR question.

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Class A

The floor is 18,000 feet MSL, a pressure altitude with the altimeter set to 29.92, never 18,000 AGL.

14,500 ft MSL to below 18,000 ft MSL is the default en route Class E layer beneath Class A.

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Class B

You must hear the words cleared into the Class Bravo. Establishing two-way radio contact is not enough, and that is the Class C rule being borrowed.

Weather does not matter: the clearance is required regardless of conditions.

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Class C

Communications are established when the controller answers with your call sign, including November 1234 Alpha, standby. A reply of aircraft calling, standby does not establish them.

The 20 NM outer area is a service, not airspace, and it carries no entry or equipment requirement of its own.

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Class D

The height is above the airport elevation, but the charted box is MSL. 4,000 above the airport is the Class C ceiling.

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Class E floors and Class G

Magenta is the lower floor (700), blue is the higher one (1,200). Reversing them is the classic chart-reading error.

Above 14,500 ft MSL the airspace is Class E, except airspace less than 1,500 ft above the terrain.

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Transponder and ADS-B Out airspace

Class D is on neither list. The 30 NM Mode C veil is charted as a solid magenta ring and is often forgotten entirely.

The 10 NM / 4,000 ft figures belong to the Class C shelf, and 20 NM to the Class C outer area; neither is the veil.

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Special use airspace and TFRs

A four-digit military training route number such as VR1207 means the route is flown at or below 1,500 ft AGL; three digits mean some portion is above it.

Controlled firing areas are the special use airspace that is never charted, because activity stops when an aircraft is detected.

A disaster or hazard TFR is issued under 91.137 and normally has a 3 NM radius up to 2,000 ft AGL.

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Datum, station and arm

The datum never moves. The centre of gravity does, with every change of loading.

A station number is an arm in inches, not a moment in pound-inches.

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Moment

weight

pounds

arm

inches from the datum, signed

An item forward of the datum has a negative arm and so a negative moment, which is subtracted from the total moments even though its weight is still added to the total weight.

Adding weight and arm instead of multiplying, or dividing them, produces the two wrong answers on offer.

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Centre of gravity

Convert fuel from gallons to pounds before anything else: 75 gallons of avgas is 450 lb, not 75 lb.

Every item counted in the weight column must also be counted in the moment column. Dropping one moment while keeping its weight is the standard trap.

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Weight shift

distance shifted

the gap between the two stations, not the new station number

Use the distance between the old and new stations. Moving 100 lb from station 30 to station 150 is a 120-inch shift, not a 150-inch one.

Weight moved aft moves the CG aft: add. Weight moved forward: subtract.

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Weight added or removed

The distance is measured from the old CG to the new item, and the divisor is the new total weight, not the old one.

Adding weight aft of the CG always moves the CG aft. Subtracting in that case is the offered error.

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Standard fluid weights

Applying the oil figure to the fuel is the most expensive slip available: fuel quantities are large, so the error compounds.

Oil is often carried at a negative arm, forward of the datum.

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Useful load, payload and zero fuel weight

Useful load includes usable fuel and drainable oil; payload does not. That is the whole difference between the two definitions.

Zero fuel weight includes every occupant and every bag, so it is never the basic empty weight and never includes fuel.

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Overload and load factor

100 lb over gross in a normal category airplane is a potential 380 lb structural overload, because the structure must carry 3.8 times whatever it supports.

An aft CG outside the approved range costs stability and can make stall and spin recovery impossible; a forward CG outside it costs elevator authority in the flare.

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Pressure altitude

30.10 carries a conversion factor of −165 ft, so a 5,883 ft field has a pressure altitude of 5,718 ft. Adding the factor instead of subtracting it is the offered answer.

Field elevation equals pressure altitude only when the setting happens to be 29.92.

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Density altitude

Correcting indicated altitude for pressure gives pressure altitude, which is only the first of the two steps.

Humid air is less dense than dry air, because water vapour is lighter than the air it displaces. High humidity raises density altitude, it does not lower it.

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What high density altitude costs

The twofold takeoff penalty is a longer ground run and a shallower climb gradient after lift-off, and both matter for obstacle clearance.

True airspeed at lift-off rises with density altitude even though the indicated airspeed is unchanged, which is why the ground roll lengthens.

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Chart correction notes

Read the note attached to the table you are using. The takeoff grass note and the landing grass note use different percentages and different base figures.

A headwind decreases distance and a tailwind increases it. Applying the correction with the wrong sign gives an answer that is always on the list.

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Ground roll against total distance

Using the ground roll alone leaves out the horizontal distance flown while climbing to 50 ft. Averaging the two figures has no basis in any chart.

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Vₓ and Vᵧ

The two speeds converge with altitude and meet at the absolute ceiling, where the only remaining climb speed gives zero rate of climb.

Service ceiling is where the best rate of climb falls to 100 fpm; absolute ceiling is where it reaches zero.

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Crosswind and headwind components

θ

wind angle: runway 17 with wind from 140° gives 30°

At 30° the crosswind is half the wind speed; at 45° both components are about 0.7 of it; at 60° the crosswind is about 0.87 and the headwind is half. An angle over 90° gives a tailwind.

The maximum demonstrated crosswind component in the POH is performance information from a certification flight test, not an operating limitation.

A 45 kt power-off stall speed gives a 9 kt certification crosswind: two tenths of the stall speed, not half of it.

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True course to compass heading

TC

true course, measured off the chart

WCA

wind correction angle: right is plus, left is minus

V

variation: east is least (subtract), west is best (add)

D

deviation, read off the compass correction card for that heading

East is least and west is best applies to variation only, and only when going from true to magnetic. Deviation is applied with the sign printed on the card.

Work the chain in order. Skipping the wind correction angle or adding an easterly variation is the pair of errors the distractors are built from.

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Time, speed and distance

Divide by groundspeed, never by true airspeed: groundspeed is what elapsed time is made of.

1.5 hours is 1 hour 30 minutes, not 1 hour 50. Carrying the decimal straight across as minutes is the trap in every time problem.

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Fuel required and endurance

38 gallons at 8 GPH is 4.75 hours, entered on the flight plan as 4 hours 45 minutes. 4 hours 75 minutes is not a clock time.

Only usable fuel counts. Unusable fuel is part of the empty weight and cannot be planned on.

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The 60-to-1 rule

VOR course guidance is angular, so full-scale deflection covers more ground the further you are from the station. GPS deviation is linear and does not spread with distance.

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VOR accuracy check, 91.171

Ground checks are tighter (4°) than airborne checks (6°), because the airplane is not adding position error of its own.

Log the date, place, bearing error and signature. Nothing else is required, and nothing less will do.

On a VOT the CDI centres with the OBS on 0° and a FROM flag, or 180° and a TO flag.

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Sectional chart scale

Measure against the latitude scale on a meridian, where 1 minute is 1 NM, or against the printed scale bars.

Half an inch on a sectional is 4 statute miles, not 8: the 8 is what a whole inch represents.

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The lift equation

C_L

coefficient of lift for the airfoil, set by angle of attack

ρ

air density in slugs per cubic foot

V

velocity in feet per second

S

wing planform area in square feet

Lift varies with the square of velocity: doubling the speed at a constant angle of attack gives four times the lift, not twice.

Density and wing area enter linearly, velocity enters squared. That asymmetry is what the question is testing.

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Load factor in a level turn

φ

angle of bank in a coordinated level turn

Load factor does not grow in proportion to bank angle. It climbs at a terrific rate once the bank passes 45° or 50°, and a 90° level turn is impossible.

Weight does not change the load factor for a given bank angle, only the loads the structure must carry.

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Stall speed and load factor

Square root, not proportional. Multiplying 50 by 4 gives 200 and is always offered.

Weight raises the stall speed but never changes the critical angle of attack. The wing stalls at the same angle at any weight, bank, altitude or CG.

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Design manoeuvring speed

Lighter means slower. A lighter airplane stalls at a lower speed, so it must be slowed further for the wing to stall and unload before the limit load is reached. Believing V_A rises as weight falls is the classic error.

V_A protects against one full deflection of one control in one axis in smooth air. It is no protection against repeated or multi-axis inputs at any speed.

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Airspeed indicator markings

V_S0

stall speed, landing configuration, gear and flaps down

V_S1

stall speed in a specified (clean) configuration

V_FE

maximum speed with flaps extended

V_NO

maximum structural cruising speed

V_NE

never-exceed speed

The two arcs share no endpoints by accident: the bottom of the white arc is the flaps-down stall, the bottom of the green is the clean stall.

V_NE is the red line at the top of the yellow arc, never the top of the green arc.

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Drag and L/D MAX

L/D MAX is the best glide speed and the speed for maximum range in a propeller airplane. Maximum endurance comes at the minimum-power speed, which is slower.

Below L/D MAX the airplane is in the region of reversed command, where more power is needed to fly slower.

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Ground effect

It is not a cushion of compressed air. The airplane can lift off below its normal flying speed and then sink back on climbing out of ground effect: performance borrowed, then repaid.

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Steep turn standards

45° is the private pilot standard. 60° is the upper end of the handbook range and belongs to the commercial standard.

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The standard atmosphere

15 °C is 59 °F. A choice pairing 29.92 with 15 °F is the same number wearing the wrong unit.

The 1 in Hg per 1,000 ft relationship is what makes an altimeter setting error worth 1,000 ft per inch.

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Lapse rates

The standard lapse rate describes the atmosphere as a whole; the dry adiabatic rate describes one unsaturated parcel being lifted through it. Swapping 2 and 3 is the trap.

An actual lapse rate steeper than the dry adiabatic rate means the column is unstable.

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Convective cloud base

T

surface temperature, °F

DP

surface dewpoint, °F

4.4

convergence rate: 5.4 °F cooling minus 1 °F dewpoint fall, per 1,000 ft

Divide by the convergence rate of 4.4, not by the dry adiabatic rate of 5.4. Both numbers appear in the derivation, and both appear in the answers.

The formula is stated in Fahrenheit. Feeding it Celsius degrees gives a number that is wrong by nearly a factor of two.

Fog seldom forms while the spread is more than 2 °C: a small spread means high relative humidity, nothing about precipitation or stability.

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Thunderstorms: ingredients and stages

The mature stage starts when rain reaches the ground, not when the anvil appears. Hazards peak toward the end of the mature stage.

Stable air and an inversion suppress convection; they are not ingredients.

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Thunderstorm avoidance and microbursts

The 90-knot figure is the total change across the microburst, twice the 45-knot one-sided surface wind. Quoting 45 is reading only half the crossing.

Severe turbulence can be met 20 miles laterally from a severe storm, in clear air, under the anvil.

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Structural icing

Almost all icing occurs between 0 and −20 °C, with about half the reports between −8 and −12 °C. Below about −20 °C clouds are mostly ice crystals and produce little icing.

Freezing rain or ice pellets mean warmer than freezing air lies above you. Climbing is the wrong instinct; the warm layer is where the supercooled water came from.

High relative humidity alone is not visible moisture: the water has to be present as droplets.

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AIRMET and SIGMET

SIGMET: severe icing, severe or extreme turbulence, widespread dust or sand below 3 miles, volcanic ash. Valid 4 hours, or 6 for tropical cyclones and volcanic ash.

Convective SIGMET: embedded or lines of thunderstorms, or hail 3/4 inch or larger. Issued hourly at 55 past the hour, valid 2 hours, and a bulletin reading NONE is still issued when nothing qualifies.

AIRMET covers moderate intensities, SIGMET covers severe ones. Matching severe conditions to a 6-hour life mixes the two products.

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IFR conditions and fog

Radiation fog needs the ground to cool, so it forms over land, not water, and burns off with heating or wind.

Upslope fog, unlike radiation fog, can form in windy conditions and persists as long as the upslope flow lasts.

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Light gun signals

Every colour means something different on the ground than in flight, except alternating red and green. The distractors are always the other half of the same row.

Acknowledge by rocking the ailerons or moving the rudder by day, and by blinking the landing or navigation lights at night.

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Transponder codes

7500 is never assigned by ATC without the pilot reporting interference first; refuse it in any other situation. A controller will ask you to verify it.

When changing codes, avoid sweeping through the emergency codes: 2700 to 7200 goes by way of 2200, not 7700.

Squawk 7700 and Mode C when a distress condition arises and you cannot immediately reach a facility, then establish communications.

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Frequencies to know

122.9 is MULTICOM, for fields with nothing on them. 122.95 is the UNICOM where a tower or FSS exists, and wind and runway information may not be available on it.

121.5 is guarded by direction-finding stations, military towers, most civil towers and radar facilities.

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Pilot-controlled lighting

Key 7 times first even if you want a lower setting: it guarantees the system is active and the lights are on before you step them down.

The lights cannot be keyed off, and generally stay on for the full 15 minutes.

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Self-announce positions on CTAF

At a non-towered field in Class G the pattern is left-hand for a powered fixed-wing airplane unless light signals or markings show otherwise.

Enter the pattern on the downwind, abeam the midpoint of the runway, at pattern altitude.

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The AIM oxygen recommendation

These are recommendations, not the regulation. 12,500 / 14,000 / 15,000 are the 91.211 legal thresholds and answer a different question.

The night figure is 5,000 ft because night vision starts to deteriorate at cabin altitudes that low.

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The four hypoxias

Alcohol produces histotoxic hypoxia: the oxygen arrives and the cells cannot use it. Carbon monoxide produces hypemic hypoxia: the oxygen never gets loaded.

Hyperventilation looks like hypoxia but comes from blowing off too much carbon dioxide. On oxygen at altitude with tingling and lightheadedness, check the equipment first, then slow the breathing rate.

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Time to lose corrective action

The 1-to-2-minute and 30-to-60-second figures belong to 30,000 and 35,000 ft and are far above any private pilot altitude.

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Carbon monoxide

200 times is why trace quantities matter. 20 times would not explain the hazard; 2,000 times is not a figure the handbooks give.

Suspect it whenever the cabin heater is on and a headache, dizziness or drowsiness appears: shut the heater off and open fresh air vents.

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Scuba diving before flight

A flight to a cabin altitude of 6,000 ft after a decompression-stop dive still needs the 24-hour wait: the dive type, not just the altitude, sets the interval.

48 hours is the carbon monoxide clearance time, not a diving interval.

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Alcohol, 91.17

0.04 is half the usual highway driving limit, and 0.08 is always offered. 12 hours overstates the interval the regulation sets, though it is a common personal rule.

An alcohol-related motor vehicle action must be reported in writing to the FAA Civil Aviation Security Division within 60 days.

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Night vision

Rods do the night seeing and they are absent from the fovea, so staring straight at a dim object puts its image on the one part of the retina that cannot see it.

Dim red cockpit lighting assists adaptation but makes red chart markings disappear; one bright white light destroys the adaptation outright.

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