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91 Cards in this Set
- Front
- Back
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DME Range
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200nm at 30,000ft
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DME: Factors affecting Range
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1. Height of transmitter
2. Height of receiver 3. Power of transmitter 4. Intervening high ground" |
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DME Accuracy
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DME: ±1/2nm or 3% of slant range, whichever is greater
B RNAV +/- 5nm for 95% of time P RNAV: 0.5nm of track |
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DME Advantages
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1. Weather interference reduced
2. Increase in route capacity 3. Lower power req 4. Ease ATC congestion, reduce pilot load |
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DME: Other Info
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1. Random PRF technique to prevents locking responses meant for other a/c
2. Trans/recv on diff freq to prevent swamping/ & self-triggering 3. Twin pules of 12us to prevent unwanted transponer trigger 1. Search 150 pps, if not locked 60 pps; when locked, 25-30 pps, average 27 pps 2. Ground capacity 2700 pps = 100 aircraft; Beyond 100; beacon saturates, will lock-on stronger signals |
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SSR General Info
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Ground: Interrogator, directional
A/C: transponder, non-directional UHF Trans: A/c 1090MHz, Grd 1030MHz Secondary Radar Twin Pulse (Jittered), Pulse Spacing Code A: 8µs (identi) ; Code B: 17µs (identi); Code C:21µs (height info); Code D:25µs (experim) PRF = 250 per second |
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SSR Range
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200nm
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SSR: Factors affecting Range?
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None
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SSR Accuracy
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±200ft height accuracy on mode C
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SSr Advantages
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1. Longer range
2. No clutter, unwanted echoes 3. Reply signals give range, brg, height, id, destination, pt of leaving airspace |
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DME Range
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200nm at 30,000ft
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DME: Factors affecting Range
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1. Height of transmitter
2. Height of receiver 3. Power of transmitter 4. Intervening high ground" |
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DME Accuracy
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DME: ±1/2nm or 3% of slant range, whichever is greater
B RNAV +/- 5nm for 95% of time P RNAV: 0.5nm of track |
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DME Advantages
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1. Weather interference reduced
2. Increase in route capacity 3. Lower power req 4. Ease ATC congestion, reduce pilot load |
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DME: Other Info
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1. Random PRF technique to prevents locking responses meant for other a/c
2. Trans/recv on diff freq to prevent swamping/ & self-triggering 3. Twin pules of 12us to prevent unwanted transponer trigger 1. Search 150 pps, if not locked 60 pps; when locked, 25-30 pps, average 27 pps 2. Ground capacity 2700 pps = 100 aircraft; Beyond 100; beacon saturates, will lock-on stronger signals |
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SSR General Info
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Ground: Interrogator, directional
A/C: transponder, non-directional UHF Trans: A/c 1090MHz, Grd 1030MHz Secondary Radar Twin Pulse (Jittered), Pulse Spacing Code A: 8µs (identi) ; Code B: 17µs (identi); Code C:21µs (height info); Code D:25µs (experim) PRF = 250 per second |
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SSR Range
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200nm
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SSR: Factors affecting Range?
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None
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SSR Accuracy
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±200ft height accuracy on mode C
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SSr Advantages
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1. Longer range
2. No clutter, unwanted echoes 3. Reply signals give range, brg, height, id, destination, pt of leaving airspace |
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SSR Disadvantages
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1. A/c must carry equip (UK, strict regulatn)
2. Compulsory under IFR to carry Mode A 4096 and Mode C |
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SSR Other Info
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1. Fruiting - A/c near >2 SSR stations cause non-synchronous interference
2. Garbling - 2 near-by A/c producing synchronous interfering 12 pulse train = 4096 codes; 0000 to 7777 0000 - malfunction 2000 - from airspace not req SSR 7000 - Conspicuity 7007 - Observation flights |
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AWR General Info
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SHF 9375Mhz
3.2cm wavelength commonly used Primary Radar Range by Echo principle Direction by searchlight principle On a 150nm range indicator: 20nm scale, markers at 5nm inteval 50nm scale, markers at 10nm int. 150nm scale markers at 50nm int. |
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AWR Range
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Max range = 320nm
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AWR: Factors affecting range
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1. MAP: ground mapping, cosecant fan beam 70nm
2. MAN: map painting; conical pencil beam for greater range 3. WEA: Weather detection by sensitive time control(STC); Conical beam, auto gain reduction at short ranges. 4. HOLD: for storm movement tracking |
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AWR Accuracy
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Falling rain, wet hail, snow , any liquid concentration will show up.
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AWR: Factors affecting accuracy
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1. Wavelength: 3-10cm; Fine mist, haze do not reflect but retend sensitive to large water droplets
2. Beamwidth: kept as narrow as possible for good target resolution. As range inc |
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AWR Disadvantages
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1. Do not operated whilst on ground; affect health of personnel & damage equip
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AWR Other Info
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Operating on weather:
1. Select max range to detect clouds early. 2. Avoid action as range TS wi 20nm. 3. Hail asso with TS produce finger fr main echo 5nm long. Others - hooks, u-shapes, scalloped edges etc Iso-echo display: Colour CRTs, green < yellow < red/magenta Calc approx height of cloud: Rel height = 100 x range(nm) x elev in deg |
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Radio/Radio Alt General info
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SHF 4200-4400MHz (FM radio)
UHF 1600MHz (PM radar) Primary Radar Radio: FM to measure time Radar: Echo principle Radio: 50 - 2500 ft Radar: 25 - 2500 ft |
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Radio/Radio Alt Accuracy
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Radio: ±2.5ft or 3% of height
Radar: ±2ft or 2% up to 500ft |
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Radio/Radio Alt: Factors affecting accuracy
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1. Surface reflectivity; Best - water
2. limited AOB<40° |
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Radio/Radio Alt Advantages
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1. Gives actual height above grd
2. Cross check with pressure altimeter 3. Very high accuracy (for CAT 2,3 ILS, they provide tie in with autopilot to initiate initial flare in landing |
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Radio/Radio Alt Other Info
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Radio ALT:
1. Freq transmitted is varied progressively at known rate 2. Returning freq is diff from freq transmitting at that instant. 3. Indicate <0ft when on ground |
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GPWS General info
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Incorporates FM continuous wave radio altimeter (3% of range accuracy)
CPU takes inputs from radio altimeter, VSI, ILS, flaps & gear monitors 50ft - 2450ft agl |
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GPWS Disadvantages
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1. Not forward-looking
2. Nuisance and false warnings |
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GPWS Other Info
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Modes: STDGFGM
Mode 1: 50 - 2450ft, Mode 2A: 50 - 1800ft, Mode 2B: 220 - 790ft Mode 3: 50 - 700ft, Mode 4A: 50 - 500ft; Mode 4B: 50 - 500ft, Mode 5: 100 - 150ft 1. Warning can be treated as alert; when A/c 1nm & 1000ft from cloud with 5nm visibility 2. Warning a MUST reportable 3. Mode 3 & 4 auto actv during T/o & Appr |
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LORAN C General Info
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Long range aid to navigation
LF (100 KHz) Baseline 500 - 1000nm Ground Waves (both omnidirectional) Hyperbolic Cycle (pulse) matching M: 9 pulse, S: 8 pulse (S:coding delay) Measure constant difference in range (Indexing) 1000nm, max 2000nm |
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LORAN C: Factors affecting range
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* Hyperbola - line joining 2 pts of equal diff of distance bet 2 fixed pts
* available in both day and night * avail in N America, N Atlantic, Europe, Mediterranean where chains present |
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LORAN C Accuracy
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RAIM = Blinking
Good coverage +/- 0.1 - 0.2 nm Other +/- 0.5 - 1 nm |
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LORAN C Accuracy
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RAIM = Blinking
Good coverage +/- 0.1 - 0.2 nm Other +/- 0.5 - 1 nm |
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LORAN C: Factors affecting accuracy
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* Risk ambiguity greatest close to baseline extensions
* Accuracy greatest along baseline * Pulse train vs single - to measure time intervals more accurately * Chain identified by pulse group repetition rate |
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LORAN C Advantages
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* Each pulse has width 180 - 270 microsec and contain abt 18,000 cycles
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GPS General Info
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UHF 1575MHz - L1 band, civilian
1227MHz - L2 band, military 4 satellite DME continuous ranges to get fix 24 sat orbit 20200km (10900nm) at 55 deg, 12h for one orbit GPS orbits 1200km higher than GLONASS sys |
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GPS: Factors affecting accuracy
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1. Satellite Clock: correct with 4 sat, +0.5m
2. Ephemeris: sat not at precise loc, +0.5m 3. Ionospheric: density of ionosphere, +4m 4. Rx error: due to electrical noise, +1m |
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GPS Accuracy
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95% of the time, +/- 100 m (by DOD)
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GPS Advantages
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1. Use worldwide, all speeds, all altitudes
2. Highly accurate 3. Available 24hrs, no reduced accuracy |
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GPS Other info
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S-Band:
Uplink: 2227.5 MHz Downlink: 1783.74 MHz |
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VDF General Info
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Vertically polarised
VHF (118-137MHz) A3E Line of Sight Using a Doppler Aerial Line of Sight: 1.25 (√ht + √hr) |
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VDF Range
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Max Range = 250nm
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VDF: Factors affecting Range
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1. Height of transmitter
2. Height of receiver 3. Power of transmitter 4. Obstacles blocking or causing scattering of signals 5. Ground reflected waves may cause fading or sign loss |
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VDF Accuracy
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Class A: ± 2 °
Class B: ± 5 ° Class C: ± 10 ° Class D: > 10 ° |
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VDF:Factors affecting Accuracy
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1. Propagation Error - uneven terrain
2. Site Error - reflections from objects 3. Overhead station (cone no bearing) 4. A/c attitude (horizontal p. vs vertical p.) 5.InstrumentError-±1° |
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VDF Advantages
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1. Simple aerial construction
2. Practically static-free |
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VDF Disadvantages
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1. Ground wave limiting range - hence limited to short range radio communication.
2. Communication limited to line of sight |
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VDF Other Info
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QDM: a/c magnetic HDG to steer to station
QDR: a/c magnetic bearing from station QUJ: a/c true track to station QTE: a/c true bearing from station VHF Letdown service: QDM: pilots responsibility QGH: controller's responsibility |
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ADF/NDB General Info
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Vertically polarised
LF/MF (200-300kHz, 300-1750kHz) N0N A1A (BFO required) N0N A2A Ground (surface) Waves Sense / Loop Aerial (Cardioid) Range (water) = 3 x √watt Range (land) = 2 x √watt |
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ADF/NDB Range
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Max Range = 200nm
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ADF/NDB:Factors affecting range
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1. Transmission Power ↑4x → range ↑2x
2. Frequency decrease, range increase 3. Type of terrain (longer over water) 4. Night effect (200nm by day/ 70nm night) 5. Static: thunderstorm bear errors |
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ADF/NDB Accuracy
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NDB accuracy ± 5°
ADF accuracy ± 2° |
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ADF/NDB: Factors affecting accuracy
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1. Night effect - fading & signal loss
2. Thunder Storm effect 3. Interference (Static & Proximity Station) 4. Terrain effect (Mountain blockage & Costal refraction) 5. ICAO signal/noise protection ratio = 3:1 6. Quadrantal effect (45°, 135°, …) |
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ADF/NDB Advantages
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1. Automated DF
2. In-built functional checks (Tran. Power not <50%) 3. Morse Inden code for identification |
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ADF/NDB Disadvantages
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1. Lack of warning device on receiver (Failed NDB)
2. Day usage only (Reduce relability due night effect) |
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ADF/NDB Other Info
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1. Locators NDB: coverage radius 10 & 25nm
2. Homing/holding: coverage 50nm 3. Long range NDB: coverage several hundreds nm 1. ADF - radio receiver give relative bearings, displayed on RBI 2. RMI displays QDM |
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VOR General Info
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Horizontally polarised
VHF (108 - 118MHz) (108 - 112MHz: Even Feq only) A9W Line of Sight Phase Comparison (Limacon) Reference:FM Variable:AM Line of Sight: 1.25 (√ht + √hr) |
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VOR Range
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Max range = 200nm
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VOR: Factors affecting range
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1. Height of transmitter
2. Height of receiver 3. Protection RANGE & ALT (50nm-25000ft) 4. Transmission power |
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VOR Accuracy
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Overall ± 5 ° accuracy (day & night)
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VOR: Factors affecting accuracy
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1. Site Error ± 1°
2. Propagation Error (Scalloping) ± 1 ° 3. Airborne Equipment Error (required servicing, when >4°) 4. Pilotage Error ± 2.5° 5. Cone Of Confusion: needle oscilates .. etc; ICAO req: COC 40° in elevation |
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VOR Advantages
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1. Operational 24hr & no night effect
2. Equipment failure device 3. Static free |
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VOR Disadvantages
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1. Numerous becon for large coverage
2. Line of sight range only |
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VOR Other Info
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1. Ident 3 letter morse, once every 10s
2.. if paired DME, every 4th suppressed to give DME ident. 3. DME ident replaced with 'Z' (MCS,MCZ) 4. Full scale deflection L/R: 10° VOR Monitoring: 1. 1° radial shift 2. Reduction in signal strength <15% 3. Failure of monitor itself |
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ILS General Info
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Horizontally polarised
VHF (localiser): 108-112 MHz; Even Freq UHF (glide): 329 - 335 MHz" A8W (Both localiser & glidepath) Line of Sight Localiser - azimuth Glidepath - vertical Inner, Middle, Outer Markers - range check Localiser: 25nm, ±10° wide, 7° vertical,17nm,±35°wide Glidepath:10nm, 8° each side 0.45xGP to 1.75xGP |
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ILS Accuracy
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Ground / Airborne ILS Categories:
CAT 1: Height 200ft / DH200;RVR 550m CAT 2: Height 50ft / DH100;RVR 300m CAT 3: Height 0ft / no DH;RVR 200m |
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ILS Disadvantages
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1. Only 40+ channels available
2. Lx and G/S beams fixed and narrow 3. A/c have to be sequenced, landing delay 4. No special procedures for heli, STOL a/c 5. Cannot be sited in hill |
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ILS Other Info
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Ident:
1. Localiser, glidepath paired, same ID 2. Ident on localiser transmission; 2-3 letter morse 7 groups/min; Ident first letter "I" 3. Auto suppressed if ILS unservicable Monitoring: 1. Localiser shift > 35ft 2. Glidepath change > 0.075 of GA 3. Power decrease > 50% |
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MLS General Info
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SHF (5030-5090 MHz)
Line of Sight Time Scan Reference System Back Azimuth ±40°, TRSB ±80° Range 20-30nm, 20,000ft Glidepath 0.9° - 20° |
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MLS Accuracy
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DH200 down to RVR 550m
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MLS Advantages
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1. Greater accuracy & reliability
2. Allows curve path for heli 3. Does not suffer from ground effects 4. More channels (200+) |
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MLS Other Info
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Ident: 'M' followed by 2 letters
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TCAS General Info
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Traffic Alert & Collision Avoidance Sys
UHF A/C tm 1030MHz, rec1090MHz Intruder tm 1090 MHz, rec 1030MHz Secondary Radar principle using SSR frequencies, air to air role Creates 2 protective 3D bubbles round a/c TCAS I: only TAs (traffic advisories) TCAS II: TA & RAs (resolution adv) Equip: minimum Mode A transponder Mode C: plus height information (3D) Mode S: data link allow mutual resolution of manoeuvres |
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TCAS Factors affecting range
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All other a/c with no conflict:
-hollow diamond Proximity: blue/white diamond - target w/I 6.5nm, vert sep<1200ft - no potential conflict bu |
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TCAS Accuracy
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Range: 50 km (30nm)
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TCAS: Factors affecting accuracy
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* RA disregarded only when pilot visually identify conflict & decide no action req'd
* RA vs ATC : TCAS RA has priority * Priority: windshear > GPWS > TCAS * Descent Inhibited when 700-1000ft agl * Increase in descen |
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TCAS Advantages
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Preventive advisories in red
Corrective advisories in green |
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TCAS Disadvantages
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* if TCAS II is working but not giving display
- could be other a/c has unserviceable transponder * TCAS II req other a/c to have Mode A, C or S transponder |
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TCAS Other Info
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Monitoring: - no ON/OFF; always on standby - display range 8, 16, 24 - Never select TA DISPY off when in TA only mode
TCAS Test: 8 sec with audio "TCAS TEST PASSED" - back to normal display |
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RADAR THEORY General Info
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PRF = 1/PRI
PW = min range Min range = PW (s) x 162,000 nm/s No cycles=PW x Freq (Hz) Radar range = 162,000 nm/s x PRI / 2 * Primary VS Secondary: Primary use echo from reflecting object, secondary use responses from transponder beacon * When using parabolic dish: use a large dish and short wavelength (high freq) |
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RADAR THEORY: Factors affecting range
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CRT:
Anodes are +ve wrt to Cathode To increase brilliance, make grid less -ve Flyback suppresed by making grid very -ve Focus controlled by: voltage at 2nd anode |
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RADAR THEORY Accuracy
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Advantage narrow beam in primary radar:
Improve definition, sys range, differentiation bet adjacent targets |
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DOPPLER PRINCIPLE Info
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X-band (8.8 to 9.8 GHz)
K-band (13.25 0 13.4 GHz) Principle: towards=increase freq; away = decrease freq Doppler Shift = Velocity / l Moving Rx: Fd = FV / C Moving Tx: Fd = 2 FV / C Depression angle: optimum signal return & best doppler (approx 67 deg common value) |
