FAA Private Pilot Helicopter (PRH) flashcards

A private pilot may share operating expenses of a flight with passengers, provided the pilot pays at least a pro rata share, including fuel, oil, airport expenditures, or aircraft rental fees.

• Pilot must pay at least equal share among occupants
• Limited to fuel, oil, airport fees, and rental costs
• Cannot be used to hold out as a common carrier
• Distinct from compensation for hire, which requires a commercial certificate

Memory trick: Split the gas bill evenly — pilot pays their fair share, not less.

Fraudulent or intentionally false entries in required records or logbooks are grounds for suspension or revocation of any certificate held.

• Applies to any record or report required to be kept under Part 61
• Covers applications for certificates as well as logbook entries
• Can affect ALL certificates/ratings held, not just the one in question

Memory trick: 'Fake it, lose it all' – lying costs every certificate you hold.

The drag created by the friction of air passing over the rotor blade's surface and its basic airfoil shape, present even when the blade generates no lift.

• One of three main types of rotor drag: profile, induced, and parasite
• Exists independent of lift production
• Increases somewhat with airspeed due to higher airflow velocity
• Distinct from induced drag (lift-related) and parasite drag (non-lifting components)

Memory trick: Profile drag is the blade's 'skin friction tax'—paid even with zero lift.

Excessive up-and-down flapping of rotor blades during startup or shutdown at low RPM, most often in strong or gusty wind conditions, that can cause a blade to strike the tail boom.

• Occurs at low rotor RPM before centrifugal stiffening takes effect
• Most common with semirigid (teetering) two-blade rotors
• Mitigated by facing the helicopter into the wind and using proper cyclic technique during start/stop

Memory trick: Sailing blades flap like sails in the wind before they stiffen

A high-speed aerodynamic phenomenon where airflow over the advancing blade tip approaches or exceeds the speed of sound, creating shock waves, increased drag, and vibration.

• Occurs on the advancing (high relative wind speed) side of the disk
• Distinct from retreating blade stall which occurs on the low-speed side
• Aggravated by high forward airspeed and high rotor RPM

Memory trick: Advancing blade races toward the sound barrier and hits a wall of shock

Higher gross weight increases the rate of descent in autorotation and reduces the margin for controlling rotor RPM, making energy management during the flare more critical.

• Heavier weight requires more upward airflow to maintain rotor RPM
• Descent rate increases with gross weight in autorotation
• Flare timing and technique become more critical at higher weights

Memory trick: Heavier helicopter falls faster and needs a sharper flare.

VNE decreases with altitude because reduced air density requires a higher retreating blade angle of attack, increasing the risk of retreating blade stall at lower forward speeds.

• VNE placards often show reduced speed with altitude
• Retreating blade AOA increases with lower air density
• Higher AOA at altitude brings stall closer at a given airspeed

Memory trick: Thin air, thick trouble — retreating blade stalls sooner.

A visual ground marking installed at airports without an operating control tower that shows wind direction, landing direction, and traffic pattern direction for each runway.

• Traffic pattern indicators are L-shaped and show whether turns are left or right for a given runway
• The tetrahedron shows landing direction (points into the wind)
• A wind sock or wind cone always points into the wind, showing where the wind is coming from

Memory trick: Circle Wind Tetra Strip Turns — 'Cats Wear Tiny Striped Ties'

In Class G airspace at or below 1,200 feet AGL during the day, VFR flight requires only 1 statute mile visibility and remaining clear of clouds.

• Applies below 1,200 ft AGL
• Daytime only for these reduced minimums
• Night minimums increase to 3 SM and 1,000/500/2,000 cloud clearance
• Found in 14 CFR 91.155

Memory trick: Below 1,200 by day, just stay a mile away (from clouds) and see a mile ahead.

The ratio of total lift required to aircraft weight during a coordinated level turn, calculated as 1 divided by the cosine of the bank angle.

• 60-degree bank produces 2.0 G load factor
• Increased load factor increases power required and stall/blade-stall risk
• Steep turns can cause rotor RPM decay if power/collective is not adjusted

Memory trick: 60 degrees doubles your weight—2 G's on the gauge

14 CFR 91.155(b) allows helicopters operating below 1,200 feet AGL to fly with less than standard VFR visibility (down to 1/2 mile) if clear of clouds and operated at a safe speed for see-and-avoid.

• Applies below 1,200 ft AGL
• Minimum visibility can be as low as 1/2 SM
• Must remain clear of clouds
• Speed must allow time to see and avoid traffic

Memory trick: Helicopters can 'hover' below the fixed-wing visibility rule down to half a mile.

A graph showing the power needed to maintain level flight at various airspeeds; its lowest point identifies the maximum endurance airspeed.

• Bottom of curve = minimum power required = best endurance
• Tangent from origin to curve = best range airspeed
• Curve rises again at high speed due to increasing parasite drag

Memory trick: Bottom of the bowl = longest time in the air (endurance)

Runway Visual Range (RVR) is the horizontal distance a pilot can see down the runway from the approach end, typically measured by instruments. It's reported in METARs and used for instrument flight rule (IFR) operations, especially during low visibility conditions.

• Reported in feet or meters.
• Indicates visibility along a specific runway.
• Crucial for takeoff and landing minimums in IFR.

Memory trick: METARs Reveal Very Important Runway Data.

An AIRMET Tango is an in-flight weather advisory issued for moderate turbulence, sustained surface winds of 30 knots or greater, or non-convective low-level wind shear. It is intended for all aircraft, including helicopters, to highlight potentially hazardous weather.

• Issued for moderate turbulence.
• Also covers sustained surface winds ≥ 30 knots.
• Indicates non-convective low-level wind shear.

Memory trick: STZ: Sierra (visibility), Tango (turbulence), Zulu (icing).

Weight and balance calculations ensure the helicopter's total weight and center of gravity remain within safe operating limits.

• Maximum Gross Weight is a critical limit.
• Subtract all known weights from Max Gross Weight to find remaining capacity.
• Fuel weight must be accounted for accurately.

Memory trick: Start big, subtract the knowns, find the fuel space.

During autorotation, rotor RPM must be maintained within the specified green arc to ensure sufficient kinetic energy for the landing flare and cushioning.

• Rotor RPM stores kinetic energy.
• Green arc indicates safe and effective RPM range.
• Energy is converted to lift during the flare.

Memory trick: Keep the rotor 'green' to have 'juice' for the landing.

To carry passengers at night, a pilot must have performed at least 3 takeoffs and 3 landings to a full stop in the same category and class of aircraft within the preceding 90 days, during the period 1 hour after sunset to 1 hour before sunrise.

• 3 takeoffs and 3 landings to a full stop.
• In same category and class of aircraft.
• Within preceding 90 days.
• Performed between 1 hour after sunset and 1 hour before sunrise.

Memory trick: 90 days, 3 up, 3 down, for passengers, day or night.

A visual illusion where an approach over upsloping terrain (especially at night) makes a pilot perceive they are too high, leading to a dangerously low and fast approach. The opposite occurs with downsloping terrain.

• Occurs over sloping terrain (upslope or downslope).
• At night, with limited visual cues, it is exacerbated.
• Upslope: Pilot feels too high, flies lower approach.
• Downslope: Pilot feels too low, flies higher approach.

Memory trick: Slope tricks your eyes, making the sky a lie.

A visual illusion where a pilot misjudges the distance to an object because its size is incorrectly perceived. This often occurs at night or over featureless terrain.

• Misjudgment of distance based on perceived size.
• Common at night or in low visibility.
• Can lead to errors in approach and landing.

Memory trick: Seeing size wrong makes distance a song (of error).

Low-level wind shear is a sudden, drastic change in wind speed and/or direction over a very short distance, typically within 2,000 feet AGL. It can occur horizontally, vertically, or both, and is particularly hazardous during takeoff and landing.

• Can be caused by fronts, thunderstorms, terrain, or temperature inversions.
• Causes uncommanded changes in airspeed, altitude, and rotor RPM.
• Extremely dangerous for all aircraft, especially helicopters, during critical phases of flight.

Memory trick: Wind Shear: Wicked Sudden Changes Hurt Airplanes.

In a TAF, a 'PROB' group indicates the probability of occurrence of specific weather conditions during a defined time period. 'PROB30' means a 30% chance, while 'PROB40' indicates a 40% chance. These groups are used for transient or intermittent conditions.

• Indicates likelihood, not certainty.
• Followed by a two-digit percentage (30 or 40).
• Includes a start and end time for the probability.

Memory trick: TAF PROB: Predicts Rare Occurrences of Bad Weather.

Operating a helicopter OGE requires sufficient power to overcome induced drag without the benefit of ground effect. Maximum OGE hover weight is determined by atmospheric conditions and helicopter power.

• OGE requires more power than IGE.
• Max OGE hover weight decreases with higher density altitude.
• Exceeding this weight means the helicopter cannot sustain an OGE hover.

Memory trick: Too heavy for OGE? Drop the weight or don't go up!

Higher altitudes mean lower air density, which reduces engine power, rotor efficiency, and ultimately the helicopter's overall performance.

• Less power available from the engine.
• Reduced rotor thrust for a given blade angle.
• Increased takeoff distance and reduced climb rate.

Memory trick: High mountains mean thin air, making choppers struggle.

Indicated Airspeed (IAS) is what the airspeed indicator shows. True Airspeed (TAS) is the actual speed through the air. For a constant IAS, TAS increases with altitude due to decreasing air density.

• IAS is based on dynamic pressure.
• Air density decreases with altitude.
• To maintain constant dynamic pressure in less dense air, true speed must increase.

Memory trick: Thin air makes the true speed 'fly' faster than indicated.

Rime ice is an opaque, white, and granular ice formation that occurs when small supercooled water droplets freeze instantly upon impact with an aircraft. It typically forms in stratiform clouds and at colder temperatures.

• Opaque, milky white appearance.
• Brittle and rough texture.
• Forms rapidly, often at colder temperatures (-10°C to -20°C).

Memory trick: Clear Rime Mixed: Icy Types You'll Find.