Private Pilot Written Test Questions and Answers

Correct answer: C. September 30, 2016.

Under 14 CFR 91.413(a) a transponder must have been tested and inspected within the preceding 24 calendar months. Calendar months run to the end of the month, so an inspection on September 1, 2014 remains valid through the last day of September 2016: September 30, 2016. September 30, 2015 would be only 12 months, and September 1, 2016 ignores the calendar-month rule.

Source: 14 CFR 91.413(a)ACS PA.I.B.K1b

Correct answer: B. Airplane, rotorcraft, glider, lighter-than-air.

For airman certification, 14 CFR 61.5(b)(1) lists the aircraft category ratings: airplane, rotorcraft, glider, lighter-than-air, powered-lift, powered parachute and weight-shift-control aircraft. Gyroplane, helicopter, airship and free balloon are classes within the rotorcraft and lighter-than-air categories, and single-engine/multiengine land and sea are airplane class ratings (61.5(b)(2)).

Source: 14 CFR 61.5(b)(1)ACS PA.I.A.K1

Correct answer: B. the pilot in command.

14 CFR 91.107(a) prohibits taking off unless the pilot in command ensures that each person on board has been briefed on how to fasten and unfasten the safety belt and shoulder harness, and has been told to fasten it for surface movement, takeoff and landing. The duty belongs to the PIC, not to the passengers themselves or to whoever occupies the right seat.

Source: 14 CFR 91.107(a)ACS PA.II.B.K1

Correct answer: C. 3402.5 hours.

14 CFR 91.409(b) allows the 100-hour limit to be exceeded by up to 10 hours only to reach a place where the inspection can be done, and the excess time must be included in computing the next 100 hours. The next inspection is therefore still based on the original due time: 3302.5 + 100 = 3402.5 hours, not 3309.5 + 100 = 3409.5. 3312.5 is just the 10-hour ferry allowance, and 3395.5 subtracts the overrun twice.

Source: 14 CFR 91.409(b)ACS PA.I.B.K1b

Correct answer: A. 90 days.

Under 14 CFR 61.57(a), to act as pilot in command of an aircraft carrying passengers you must have made at least three takeoffs and three landings within the preceding 90 days, as sole manipulator of the controls, in an aircraft of the same category, class and type (if a type rating is required). 30 and 60 days are not periods used in this regulation.

Source: 14 CFR 61.57(a)ACS PA.I.A.K1

Correct answer: A. After one-half the battery's useful life.

14 CFR 91.207(c) requires ELT batteries to be replaced (or recharged, if rechargeable) when the transmitter has been in use for more than 1 cumulative hour or when 50 percent of the battery's useful life has expired. There is no fixed 24-month or every-inspection replacement rule; 91.207(d) requires an annual ELT inspection, not a new battery.

Source: 14 CFR 91.207(c)

Correct answer: A. The pilot in command.

14 CFR 91.7(b) makes the pilot in command responsible for determining whether the aircraft is in condition for safe flight, and 91.3 gives the PIC final authority for its operation. The owner or operator is responsible for maintaining airworthiness (91.403), and the mechanic signs for the work he or she performed, but neither decides whether this flight is safe.

Source: 14 CFR 91.7(b)

Correct answer: A. Normal, utility, acrobatic.

14 CFR 1.1 says that for the certification of aircraft, category means a grouping by intended use or operating limitations, such as transport, normal, utility, acrobatic, limited, restricted and provisional. Airplane, rotorcraft and glider are categories for airman certification, and landplane/seaplane describe a class.

Source: 14 CFR 1.1

Correct answer: B. Single-engine land and sea, multiengine land and sea.

For airman certification, 14 CFR 1.1 defines class as a grouping of aircraft with similar operating characteristics, such as single-engine, multiengine, land, water, gyroplane, helicopter, airship and free balloon; 61.5 lists single-engine land and sea and multiengine land and sea for airplanes. Airplane, rotorcraft, glider and lighter-than-air are categories.

Source: 14 CFR 1.1

Correct answer: C. The signature, certificate number, and kind of certificate held by the person approving the work and a description of the work must be entered in the aircraft maintenance records.

14 CFR 43.9(a) requires a maintenance record entry for preventive maintenance containing a description of the work, the date of completion, the name of the person who performed it and, if the work is approved for return to service, the signature, certificate number and kind of certificate of the person approving it. The other options leave out the required approval information.

Source: 14 CFR 43.9(a)

Correct answer: A. No later than 60 days after the motor vehicle action.

14 CFR 61.15(e) requires a written report of each motor vehicle action (such as a DWI conviction or license suspension) to the FAA's Civil Aviation Security Division no later than 60 days after the motor vehicle action. It is a separate report from the medical application, and the deadline is 60 calendar days, not 30 working days.

Source: 14 CFR 61.15(e)

Correct answer: C. federal, state, or local law enforcement officer.

14 CFR 61.3(l) requires a person holding a pilot or medical certificate to present it for inspection on request of the Administrator, an authorized representative of the NTSB or TSA, or any Federal, State or local law enforcement officer. A generic 'person in a position of authority' is not in the rule.

Source: 14 CFR 61.3(l)

Correct answer: C. An appropriate pilot certificate and an appropriate current medical certificate if required.

Under 14 CFR 61.3(a) and (c), a pilot acting as PIC must have in physical possession or readily accessible in the aircraft an appropriate pilot certificate and, when required, a current medical certificate (along with photo identification). Logbooks showing checkouts, flight reviews or recency need not be carried.

Source: 14 CFR 61.3(a)

Correct answer: B. If a donation is made to a charitable organization for the flight.

14 CFR 61.113(d) lets a private pilot act as PIC of a charitable, nonprofit or community event flight in which passengers make a donation to the sponsoring organization, provided the conditions of 91.146 are met. Passengers paying all the operating expenses is not allowed; a private pilot may share expenses only on a pro rata basis (61.113(c)).

Source: 14 CFR 61.113(d)

Correct answer: C. Frost spoils the smooth flow of air over the wings, thereby decreasing lifting capability.

Frost roughens the wing surface and disrupts the smooth airflow over it, causing early airflow separation; as PHAK Ch. 12 explains, this reduces the wing's lifting capability and increases drag and stall speed, possibly preventing the airplane from becoming airborne. Frost never increases lift, and it does not improve control effectiveness.

Source: PHAK (FAA-H-8083-25)ACS PA.I.C.K3k

Correct answer: B. the start of precipitation.

A thunderstorm cell goes through cumulus, mature and dissipating stages. According to PHAK Ch. 12, precipitation beginning to fall from the cloud base signals that a downdraft has developed and the cell has entered the mature stage. The anvil top forms later as the storm reaches maturity, and continuous downdrafts throughout the cell characterize the dissipating stage.

Source: PHAK (FAA-H-8083-25)ACS PA.I.C.K3h

Correct answer: B. friction between the wind and the surface.

Above the friction layer, wind blows nearly parallel to the isobars as pressure gradient and Coriolis force balance. Within roughly the lowest 2,000 feet, friction with the surface slows the wind, which weakens the Coriolis force. The wind then turns toward lower pressure, which is why a southwesterly wind aloft becomes more southerly at the surface (PHAK Ch. 12). Coriolis force is weaker, not stronger, at the surface, and the pressure gradient is not what causes the directional change.

Source: PHAK (FAA-H-8083-25)ACS PA.I.C.K3b

Correct answer: C. an increase in temperature as altitude increases.

A temperature inversion is by definition a layer in which temperature increases as altitude increases (PHAK Ch. 12). The warm layer on top acts as a lid on stable air, trapping haze, smoke and fog, so visibility is typically poor below the inversion and better above it, the reverse of the other visibility statement. Inversions go with stable air, not with clouds of extensive vertical development.

Source: PHAK (FAA-H-8083-25)ACS PA.I.C.K3c

Correct answer: A. produces stratus type clouds.

When moist, stable air is forced up sloping terrain, it cools until it condenses. Because stable air resists vertical motion, the result is a layered, stratus-type cloud or upslope fog (PHAK Ch. 12). Showers, thunderstorms and convective turbulence come from lifting unstable air, not stable air.

Source: PHAK (FAA-H-8083-25)ACS PA.I.C.K3f

Correct answer: A. Frost will disrupt the smooth flow of air over the wing, adversely affecting its lifting capability.

Even a thin layer of frost roughens the wing surface and disrupts the smooth airflow, which causes early airflow separation, less lift and more drag; PHAK and AC 91-74B warn it can prevent the airplane from becoming airborne at normal takeoff speed. Frost does not usefully change camber, and it raises rather than lowers the stall speed.

Source: PHAK (FAA-H-8083-25) · AC 91-74B

Correct answer: B. a rain cloud.

PHAK Chapter 12 explains that the prefix nimbo- or suffix -nimbus in a cloud name means a rain cloud, as in nimbostratus and cumulonimbus. Extensive vertical development is indicated by cumulus, and 'alto' marks middle clouds.

Source: PHAK Chapter 12

Correct answer: B. height range.

Clouds are grouped into four families by the height range in which they form: low, middle and high clouds, plus clouds with extensive vertical development (PHAK Chapter 12). Shape (cumulus, stratus) and composition (water or ice) describe clouds within those families but are not the basis of the four-family division.

Source: PHAK Chapter 12

Correct answer: C. Towering cumulus clouds.

Towering cumulus clouds are built by strong rising air currents, so they indicate convective turbulence (PHAK Chapter 12). Cirrus are high ice-crystal clouds, and nimbostratus are stratiform rain clouds associated with stable air and little turbulence.

Source: PHAK Chapter 12

Correct answer: B. Cumulonimbus.

Cumulonimbus clouds (thunderstorms) contain the strongest updrafts and downdrafts and are the most turbulent clouds, as PHAK Chapter 12 and AIM 7-1-26 describe. Towering cumulus are turbulent but less so, and nimbostratus are stable, stratiform rain clouds.

Source: PHAK Chapter 12 · AIM 7-1-26

Correct answer: A. 1 mile and clear of clouds.

On Figure 26, Cooperstown Airport (S32) sits inside a magenta shaded vignette, meaning Class E airspace begins at 700 feet AGL, so the airspace at or below 700 feet AGL is Class G. For Class G at 1,200 feet AGL or less during the day, 14 CFR 91.155(a) requires 1 statute mile flight visibility and clear of clouds. The 3-mile and 1,000/500/2,000 cloud-clearance values are Class E (or Class G above 1,200 feet AGL) requirements.

Source: 14 CFR 91.155(a)ACS PA.I.E.K1

Correct answer: B. Class E.

On Figure 20, Fentress NALF (NFE), south of Norfolk near Great Bridge, is enclosed by a magenta dashed line, which the Aeronautical Chart User's Guide defines as a Class E surface area. The solid magenta rings of the Norfolk Class C airspace pass north of the field, so NFE is not in Class C. Because controlled airspace extends to the surface there, it is not Class G either.

Source: Chart User's GuideACS PA.I.E.K2

Correct answer: C. 1 statute mile, clear of clouds.

On Figure 78, Onawa (K36, elevation 1,047 ft, CTAF 123.0) has no dashed magenta Class E surface area or Class D boundary around it, so the airspace at the surface where the takeoff occurs is Class G. For day operations in Class G at 1,200 feet or less above the surface, 14 CFR 91.155(a) requires 1 statute mile visibility and clear of clouds. The 3-mile, 500/1,000/2,000 values apply in controlled airspace such as a Class E surface area. The regulations have no '0 miles' VFR minimum for airplanes.

Source: 14 CFR 91.155(a)ACS PA.I.E.K1

Correct answer: A. 1 mile.

Outside controlled airspace is Class G. The 14 CFR 91.155(a) table gives, for Class G more than 1,200 feet above the surface but below 10,000 feet MSL, a day flight visibility of 1 statute mile (with 500 below, 1,000 above and 2,000 feet horizontal from clouds). 3 miles is the night value there (and the Class C, D and E value below 10,000 MSL), and 5 miles applies at or above 10,000 feet MSL.

Source: 14 CFR 91.155(a)ACS PA.I.E.K1

Correct answer: A. 500 feet.

In Class G airspace more than 1,200 feet above the surface but below 10,000 feet MSL, 14 CFR 91.155(a) requires at night 3 statute miles visibility and cloud clearance of 500 feet below, 1,000 feet above and 2,000 feet horizontal. 1,000 feet is the required distance above clouds, and 1,500 feet is not a value in the table.

Source: 14 CFR 91.155(a)ACS PA.I.E.K1

Correct answer: C. whether the flight is VFR or IFR.

AIM 5-1-1 says that when requesting a preflight briefing you identify yourself as a pilot and provide the type of flight planned (VFR or IFR), the aircraft number or pilot's name, aircraft type, departure airport, route, destination, altitude, ETD and ETE, so the briefer can tailor the briefing. A home address and a summary of your qualifications are not part of that background information.

Source: AIM 5-1-1ACS PA.I.C.K1

Correct answer: B. identify yourself as a pilot.

AIM 5-1-1 says that when you request a preflight briefing you should identify yourself as a pilot and then give background information: VFR or IFR, aircraft number or pilot's name, aircraft type, departure airport, route, destination, altitude(s), ETD and ETE. The number of occupants is not part of the briefing request. The route of flight is provided, but not as the opening item before you identify yourself as a pilot.

Source: AIM 5-1-1ACS PA.I.C.K1

Correct answer: B. 230° true at 39 knots.

In Figure 17 the STL entry under 12,000 feet is 2339-04: 23 = 230 degrees, 39 = 39 knots, and -04 = minus 4 degrees Celsius. Winds and temperatures aloft forecasts give direction relative to true north, so the forecast is 230 degrees true at 39 knots. 56 knots is the 18,000-foot value (2356-16), and the direction is not magnetic.

ACS PA.I.C.K2

Correct answer: A. Tornadoes, embedded thunderstorms, and hail 3/4 inch or greater in diameter.

AIM 7-1-6 lists the criteria for a Convective SIGMET: severe thunderstorms (surface winds of 50 knots or more, hail of 3/4 inch or more, or tornadoes), embedded thunderstorms, lines of thunderstorms, and areas of strong thunderstorms covering a large area. Severe icing, severe turbulence and dust storms are non-convective SIGMET items, and the wind threshold is 50, not 40, knots.

Source: AIM 7-1-6

Correct answer: B. SIGMET.

AIM 7-1-6 says a (non-convective) SIGMET is issued for severe icing not associated with thunderstorms, severe or extreme turbulence or CAT, dust and sandstorms reducing visibility below 3 miles, and volcanic ash. Convective SIGMETs cover thunderstorms, and AIRMETs cover moderate icing and turbulence.

Source: AIM 7-1-6

Correct answer: A. To enable the pilot to make steeper approaches to a landing without increasing the airspeed.

Flaps are secondary flight controls that increase both lift and drag, so the airplane can fly a steeper descent angle toward the runway without picking up speed (PHAK Ch. 6; AFH Ch. 9). Relieving the pilot of continuous control pressure is the job of trim tabs, not flaps. Flaps also do not decrease wing area; extending them increases camber (and on some designs wing area) to change lift.

Source: PHAK (FAA-H-8083-25)ACS PA.I.G.K1b

Correct answer: A. more susceptible to icing.

In a float-type carburetor, fuel vaporization and the pressure drop in the venturi can cool the air below freezing, so ice can form even at moderate outside air temperatures. A fuel injection system has no venturi and injects fuel at or near the intake ports, so PHAK Ch. 7 describes it as less susceptible to icing than a carburetor system. Therefore carburetors are more, not equally or less, susceptible to icing.

Source: PHAK (FAA-H-8083-25)ACS PA.IX.C.K1b

Correct answer: C. loss of RPM.

PHAK Ch. 7 states that in an airplane with a fixed-pitch propeller the first indication of carburetor ice is a loss of RPM, because ice restricts the fuel/air flow and reduces power; engine roughness typically follows later. A drop in oil and cylinder head temperature is not the recognized first sign. With a constant-speed propeller the first sign would instead be a drop in manifold pressure.

Source: PHAK (FAA-H-8083-25)ACS PA.IX.C.K1b

Correct answer: B. 121.5 and 243.0 MHz.

AIM 6-2-4 says ELTs transmit on 121.5 MHz and 243.0 MHz (and newer ones also on 406 MHz, which satellites monitor, while keeping a 121.5 homing signal). 118.0/118.8 and 123.0/119.0 MHz are ordinary communication frequencies, not emergency beacon frequencies.

Source: AIM 6-2-4

Correct answer: B. taxiing and takeoff.

Area A on Figure 48 is the paved runway section before Runway 12's threshold, marked with white arrows along the centerline and arrowheads ahead of the threshold bar. That is a displaced threshold. Per AIM 2-3-3 and PHAK Ch. 14, the pavement behind a displaced threshold is available for taxiing and for takeoffs in either direction. An aircraft landing on Runway 12 may not touch down there; only the rollout of an aircraft landing in the opposite direction may use it. So it is correctly described as usable for taxiing and takeoff, not for landing.

Source: AIM 2-3-3 · PHAK (FAA-H-8083-25)ACS PA.II.D.K3

Correct answer: B. below the glide path.

Each VASI light unit shows white in the upper part of its beam and red in the lower part (AIM 2-1-2). On a 2-bar VASI, seeing red on both the near and far bars (illustration D in Figure 47: all six lights red) means the aircraft is below the glide path. Red over white is on the glide path, and white over white is above it.

Source: AIM 2-1-2ACS PA.III.B.K2

Correct answer: A. runway 22.

The sign shows yellow '22' on a black background with a yellow border, the format of a runway location sign. AIM 2-3-9 says its inscription is the designation of the runway on which the aircraft is located, so it confirms you are on Runway 22. A sign routing you toward a runway would be a direction or destination sign (black on yellow, with an arrow). Taxiways are identified by letters, not numbers.

Source: AIM 2-3-9ACS PA.II.D.K3

Correct answer: C. Never-exceed speed.

The red radial line on an airspeed indicator marks VNE, the never-exceed speed; operating above it can cause structural damage or failure (PHAK Ch. 8). Maneuvering speed (VA) is not marked on the airspeed indicator, and the caution range for smooth air only is the yellow arc, whose lower end is VNO, the maximum structural cruising speed.

Source: PHAK (FAA-H-8083-25)ACS PA.I.F.R2

Correct answer: B. certain metals and electrical systems within the aircraft.

Deviation is compass error caused by magnetic fields from metal parts and electrical equipment inside the aircraft, and it is recorded on the compass correction card (PHAK Ch. 8). The angular difference between true north and magnetic north is variation, a different error. Northerly turning error is a dip-related error that shows up in turns.

Source: PHAK (FAA-H-8083-25)ACS PA.VI.A.K2

Correct answer: C. miniature airplane to the horizon bar.

PHAK Chapter 8 explains that the pilot adjusts the attitude indicator in level flight by moving the miniature airplane (C in Figure 7) with the adjustment knob so it is aligned with the horizon bar (B). The horizon bar is driven by the gyro and cannot be adjusted by the pilot.

Source: PHAK Chapter 8

Correct answer: A. Monitor airport traffic and announce your position and intentions on 118.5 MHz.

The Lincoln Chart Supplement entry lists CTAF 118.5, the same frequency as the tower, which operates only 1130-0600Z. When the tower is closed, AIM 4-1-9 calls for pilots to monitor the CTAF and self-announce position and intentions on it, so reports go out on 118.5 MHz. The UNICOM frequency 122.95 is for airport services and advisories, not the CTAF at this airport.

Source: AIM 4-1-9ACS PA.III.A.K2

Correct answer: A. Lincoln Approach Control on 124.0 MHz.

At noon local time (1700-1800Z), Lincoln's Class C airspace is in effect (service 1130-0600Z). The Chart Supplement says to contact Approach Control. 14 CFR 91.130(c)(1) requires two-way radio communication with the ATC facility providing air traffic services before entering Class C. An aircraft west of the field lies in the 180-359 degree sector, whose approach frequency is 124.0 MHz. The tower is contacted later, when approach hands you off. Minneapolis Center is not the facility that serves this Class C airspace.

Source: 14 CFR 91.130(c)(1)ACS PA.I.D.K1

Correct answer: A. 1200

AIM 4-1-20 states that, unless otherwise instructed by an ATC facility, VFR pilots set the transponder to Mode 3/A code 1200 regardless of altitude, with altitude reporting enabled. Code 7600 signals a two-way radio communications failure and 7700 signals an emergency, so neither is the normal VFR code.

Source: AIM 4-1-20ACS PA.III.A.K4

Correct answer: A. chord line of the wing and the relative wind.

Angle of attack is the acute angle between the chord line of the wing and the direction of the relative wind (PHAK Ch. 5). It is measured from the airfoil's chord, not from the airplane's longitudinal axis or centerline. The angle between the longitudinal axis and the horizon is the pitch attitude, and the angle between the chord and the longitudinal axis is the angle of incidence.

Source: PHAK (FAA-H-8083-25)ACS PA.I.F.K3

Correct answer: C. Air traveling faster over the curved upper surface of an airfoil causes lower pressure on the top surface.

Bernoulli's principle says that as the velocity of a moving fluid increases, its pressure decreases (PHAK Ch. 4). Air flowing faster over the curved upper surface of the wing therefore has lower pressure than the air below, and that pressure difference produces lift. The action/reaction statement is Newton's third law, and the downward deflection of air by the lower surface is also a Newtonian explanation of lift, not Bernoulli's principle.

Source: PHAK (FAA-H-8083-25)ACS PA.I.F.K3

Correct answer: B. in conditions of reduced visibility.

Under the FAA's voluntary 'Operation Lights On' program, AIM 4-3-24 encourages pilots to turn on landing lights below 10,000 feet, day or night. It singles out operations within 10 miles of any airport, in conditions of reduced visibility, and in areas where flocks of birds may be expected. The AIM does not single out Class B airspace, and its distance is 10 miles of any airport, not 15 miles of a towered airport.

Source: AIM 4-3-24ACS PA.III.B.R1

Correct answer: A. Left aileron up, elevator neutral.

Area A in Figure 9 is a wind from ahead and to the left, a left quartering headwind. The Airplane Flying Handbook says that in a tricycle-gear airplane you turn the control wheel into the wind, which raises the aileron on the upwind (left) side so the wind cannot lift that wing, and hold the elevator neutral. Lowering the left aileron would let the wind get under the wing, and down elevator is used for tailwinds.

Source: Airplane Flying Handbook

Correct answer: A. slowing the breathing rate, breathing into a paper bag, or talking aloud.

Hyperventilation is an excessive loss of carbon dioxide caused by breathing too fast or too deeply. PHAK Ch. 17 lists the cure as slowing the breathing rate, breathing into a paper bag, or talking aloud, and AIM 8-1-3 likewise says symptoms subside once breathing is brought back under control and that breathing into a paper bag speeds the rebuilding of CO2. Breathing more deeply or faster would make the CO2 deficit worse.

Source: PHAK (FAA-H-8083-25) · AIM 8-1-3ACS PA.I.H.K1b

Correct answer: B. 545 feet.

The 5,000-foot column of Figure 38 is based on 41 degrees F, which is the standard temperature at that altitude, and shows a 495-foot ground roll. Note 2 adds 10% for each 60 degrees F above standard. The given 101 degrees F is 60 degrees F above standard, so 495 x 1.10 = 544.5, about 545 feet. The calm wind means no headwind reduction. 445 feet is the sea-level value, and 495 feet leaves out the temperature correction.

ACS PA.I.F.K1

Correct answer: C. 0° FROM or 180° TO, regardless of the pilot's position from the VOT.

A VOT transmits a test signal that radiates the same 360 radial in all directions, so the result does not depend on where the aircraft is. AIM 1-1-4 states that with the CDI centered, the OBS should read 0 degrees with a FROM indication or 180 degrees with a TO indication (an RMI shows 180). The reversed pairing (0 TO / 180 FROM) and any position-dependent reading are incorrect.

Source: AIM 1-1-4ACS PA.VI.B.K1

Correct answer: B. Drain 9 gallons of fuel.

From Figure 32: empty 2,015 lb (moment/100 1,554); front seats 425 lb x 85 in = 361.3; rear seats 300 lb x 121 in = 363.0; 44 gal main fuel 264 lb (198). Total 3,004 lb, 54 lb over the 2,950 lb maximum. At 6 lb per gallon, draining 9 gallons removes exactly 54 lb: 35 gal = 210 lb, moment 158, giving 2,950 lb and moment/100 2,436.3, inside the Figure 33 limits of 2,422 to 2,499 at 2,950 lb (CG about 82.6 in). Draining 12 gallons would leave the airplane below, not at, maximum gross weight, and transferring fuel to the auxiliary tanks does not reduce weight at all (still 3,004 lb).

ACS PA.I.F.K2f

Correct answer: C. the time between the end of evening civil twilight and the beginning of morning civil twilight.

14 CFR 1.1 defines night as the time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the Air Almanac and converted to local time. Sunset to sunrise is the period for position lights (91.209), and 1 hour after sunset to 1 hour before sunrise is the passenger-carrying recency period (61.57(b)).

Source: 14 CFR 1.1

Correct answer: C. VOR/DME.

Next to area 5 on Figure 25, the navaid symbol at Dallas/Ft. Worth International is a hexagon with a center dot enclosed in a square, which the Aeronautical Chart User's Guide identifies as a VOR/DME. A plain VOR is a hexagon without the square, and a VORTAC is a hexagon with three small rectangles attached to alternate sides.

Source: Chart User's GuideACS PA.I.E.K2

Correct answer: A. 121.5 MHz.

121.5 MHz is the international VHF emergency frequency. It is monitored by ATC facilities, many FSSs and military facilities, so a pilot who is not already talking to ATC should use it to declare a distress or urgency situation (AIM 6-3-1). 122.5 MHz is a flight service frequency and 128.725 MHz is not an emergency frequency, so neither is guaranteed to reach an emergency service.

Source: AIM 6-3-1ACS PA.III.A.K1

Correct answer: C. Wait until the temperature decreases, and recalculate the takeoff performance.

The computed 1,980 feet to clear a 50-foot obstacle leaves only 120 feet of the 2,100-foot strip, with no margin for a gravel surface, pilot technique or an aging engine. Density altitude is the problem, and it improves as the temperature drops (PHAK Ch. 11). Sound ADM (PHAK Ch. 2; Risk Management Handbook) is to wait for cooler air and recompute performance. Counting on a headwind that may not be there, or 'testing' a marginal takeoff even with a lighter load, accepts an unmitigated risk instead of removing it.

Source: PHAK (FAA-H-8083-25) · Risk Management HandbookACS PA.I.H.K4

Correct answer: B. a series of shocks causes the rotor system to become unbalanced.

The Helicopter Flying Handbook explains that ground resonance occurs on the ground when a series of shocks (for example a hard landing on one skid or gear) unbalances the rotor system and the oscillation builds through the landing gear. It is not a main/tail rotor harmonic, and the change in angle of attack between advancing and retreating blades describes dissymmetry of lift.

Source: Helicopter Flying Handbook