BR-ANAC-R-VFRH flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

VLOS definition

Visual line of sight means the remote pilot maintains direct unaided visual contact with the aircraft at all times, allowing control and separation from other aircraft and obstacles.

SISANT registration threshold

In Brazil, RPA above 250 g must be registered with ANAC through SISANT, and the registration number must be marked on the aircraft.

120 m AGL limit

Operations above 120 m (400 ft) above ground level require prior coordination with DECEA, unless specific offset rules near structures apply.

Right of way, RPA

A remotely piloted aircraft must give way to all manned aircraft and must never assume that the manned pilot can see or avoid it.

IMU function

The inertial measurement unit combines accelerometers and gyroscopes to provide attitude, angular rates and acceleration data used by the flight controller.

LiPo storage voltage

A lithium polymer cell is stored at about 3.8 V, charged fully to 4.2 V, and should not be discharged below about 3.5 V in flight.

Return-to-home failsafe

On loss of command link, the autopilot executes a pre-programmed action such as hold, return to home, or land, using a stored home point and safe altitude.

Magnetometer interference

Compass errors caused by metal structures, power lines or onboard wiring corrupt heading data and are a common cause of loss of control.

Density altitude effect

High elevation, high temperature and high humidity raise density altitude, reducing air density, thrust and climb performance while increasing takeoff distance.

Translational lift

Forward airspeed reduces induced velocity through the rotor, lowering induced power and improving efficiency compared with hovering.

Best endurance speed

The speed at which minimum power is required per unit time, giving the longest flight time for the available energy.

Excess power

Rate of climb equals available power minus power required, divided by weight; zero excess power defines the ceiling.

Center of gravity formula

Center of gravity position equals the sum of each mass multiplied by its arm, divided by the total mass, measured from the datum.

Moment calculation

Moment is mass multiplied by arm; total mass and total moment are recomputed after every loading change to verify limits.

Off-center payload effect

A payload placed away from the center of gravity forces motors to produce unequal thrust, reducing control authority and stability margins.

Hypoxia signs

Reduced oxygen causes euphoria, poor judgment, tingling and impaired vision; effects begin earlier at altitude and are hard to self-detect.

Spatial disorientation

Conflicting visual and vestibular cues produce false sensations of attitude or motion; the pilot must rely on instruments and outside references.

Fatigue effect

Fatigue reduces vigilance, slows reaction time and increases omission errors, making duty limits and rest periods safety requirements.

Standard atmosphere

Sea-level pressure 1013.25 hPa, temperature 15 degrees Celsius, with temperature decreasing 2 degrees Celsius per 1,000 feet.

QNH meaning

QNH is the altimeter pressure setting that makes the instrument indicate elevation above mean sea level when on the ground.

Crosswind component

The crosswind component equals wind speed multiplied by the sine of the angle between the wind direction and the heading.

Thunderstorm hazard

Cumulonimbus clouds contain severe updrafts, downdrafts, hail, lightning and microbursts, all hazardous to aircraft at any size.

Track versus heading

Track is the actual path over the ground, while heading is the direction the aircraft points; wind causes drift between them.

Wind correction angle

The crab angle needed to hold a track equals the arcsine of wind speed divided by true airspeed, multiplied by the sine of the wind angle.

Magnetic variation

Variation is the angle between true north and magnetic north; easterly variation is subtracted from true heading to obtain magnetic heading.

GNSS multipath

Reflections of satellite signals from buildings or terrain cause position errors, so GNSS accuracy degrades in urban and confined areas.

Preflight site survey

Before flight, identify obstacles, persons, emergency landing areas, link coverage and airspace status, and define the operating volume.

Lost link procedure

Confirm the programmed failsafe, verify return altitude clears obstacles, monitor the aircraft, and be prepared to regain manual control.

Low battery action

When the low-battery warning triggers, land immediately; the reserve must cover return to the landing area plus a safety margin.

Induced power in hover

Induced power equals thrust to the power three halves divided by the square root of twice density times disk area.

Vortex ring state

Vertical descent with low forward speed causes recirculating airflow, thrust loss and vibration; recovery uses forward speed and reduced collective.

MAYDAY versus PAN-PAN

MAYDAY, repeated three times, signals grave and imminent danger; PAN-PAN, repeated three times, signals urgency without immediate danger.