CAA NZ ATPL Theory - Flight Navigation General flashcards

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

1 in 60 rule

Off-track distance equals distance flown multiplied by track error in degrees divided by 60. It also estimates closing angle to destination and heading corrections.

Equal time point

Point along route where time to return to departure equals time to continue to destination. Distance from A = (total distance × groundspeed back) / (groundspeed out + groundspeed back).

Point of no return

Furthest point aircraft can fly and still return to departure with reserve fuel. Distance = (endurance × GS out × GS back) / (GS out + GS back).

Wind correction angle

Angle between heading and track needed to compensate for wind. Sin(WCA) = (wind speed × sin(wind angle)) / TAS; positive for wind from right.

Headwind component

Component of wind parallel to track, opposing aircraft motion. Equals wind speed × cos(angle between wind direction and track).

Crosswind component

Component of wind perpendicular to track. Equals wind speed × sin(angle between wind direction and track). Causes drift.

Maximum drift

Occurs when wind is perpendicular to track. Drift angle = arcsin(wind speed / TAS).

VOR radial

Magnetic bearing from VOR station to aircraft. CDI centered with FROM indicates aircraft on that radial; with TO indicates outbound on opposite radial.

DME slant range

Line-of-sight distance from aircraft to DME station. Ground distance = √(DME² − height²); accuracy ±0.5 NM or 3% of distance.

ADF relative bearing

Angle measured clockwise from aircraft heading to station. Magnetic bearing to station = heading + relative bearing (mod 360).

ILS localizer

Provides lateral guidance to runway centreline. Frequency 108–112 MHz; accuracy ±0.5°; course width 3°–6°.

RAIM

Receiver autonomous integrity monitoring. Detects faulty GNSS signals; requires at least 5 satellites for detection, 6 for exclusion.

RNAV

Area navigation allowing aircraft to fly any desired path within coverage of navigation aids or self-contained means. Does not require overflight of stations.

RNP

Required navigation performance. RNAV with on-board performance monitoring and alerting; specifies lateral accuracy in nautical miles (e.g., RNP 4, RNP 1).

PBN

Performance-based navigation. Area navigation based on performance requirements for aircraft operating along ATS routes, on instrument approach procedures, or in designated airspace.

LNAV/VNAV approach

RNAV approach with lateral and vertical guidance. Uses barometric or SBAS vertical guidance; minima lower than LNAV only.

Variation

Angle between true north and magnetic north. East variation: magnetic least (subtract from true). West variation: magnetic best (add to true).

Deviation

Compass error caused by aircraft magnetic fields. Applied to magnetic heading to obtain compass heading; shown on deviation card.

Isogonal

Line on chart connecting points of equal magnetic variation. Agonic line has zero variation.

True heading to magnetic

Magnetic heading = true heading ± variation. East variation subtract, west variation add. Then apply deviation to get compass heading.

Drift

Angle between heading and track. Drift = track − heading; positive when track is to the right of heading.

Track to heading

Heading = track + wind correction angle. WCA positive for wind from right; negative for wind from left.

Longitude and time

Earth rotates 15° per hour. 1° longitude = 4 minutes time difference. Local mean time = UTC + (longitude/15) hours, east positive.

Latitude distance

1 minute of latitude equals 1 nautical mile. Longitude distance for 1 minute = cosine(latitude) nautical miles.

Temperature altimetry error

When temperature is colder than ISA, true altitude is lower than indicated altitude. When warmer, true altitude is higher. Correct on approach in extreme cold.

QNH and QFE

QNH altimeter setting gives altitude above mean sea level. QFE gives height above aerodrome reference point. QNE 1013.25 hPa gives flight level.

High to low pressure

Flying from high to low pressure without adjusting altimeter causes true altitude to be lower than indicated. Altimeter overreads.

Jet stream

Strong westerly wind near tropopause. Affects groundspeed and fuel planning; can cause clear air turbulence.

NAT HLA

North Atlantic High Level Airspace. Requires RNP 4, RVSM, and CPDLC. Tracks published twice daily.

Grid navigation

Navigation using grid north, used in polar regions where magnetic compass unreliable. Grid track = true track ± convergence.

Inertial reference system

Self-contained navigation system using gyros and accelerometers. Provides attitude, heading, position, velocity. Position drift about 1 NM per hour.

Flight management system

Integrates navigation sensors, performance database, and flight plan. Computes LNAV and VNAV guidance and provides RNAV/RNP capability.