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Lernkarten
A curved MLS approach can only be performed when
DME-P is available
A Cat III ILS glidepath transmitter provides reliable guidance information down to...
the surface of the runway
In which frequency band does the Microwave Landing System (MLS) operate?
SHF = Super High frequency
The azimuth transmitter of a Microwave Landing System (MLS) provides a fanshaped horizontal approach zone that is usually...
+ or - 40° either side of the runway centre-line
MLS installations notified for operation, unless otherwise stated, provide azimuth coverage of...
+ or - 40° about the nominal courseline out to a range of 20 NM
ILS is subject to false glide paths resulting from...
multiple lobes of radiation patterns in the vertical plane
Which one of the following correctly lists the major ground based components of a Microwave Landing System (MLS)?
Separate azimuth and elevation transmitters, DME facility
Assuming a five dot display, what does each of the dots on either side of the ILS localizer cockpit display represent
0.5 degrees
An aircraft tracking to intercept the Instrument Landing System (ILS) localiser inbound on the approach side, outside the published ILS coverage angle...
may receive false course indications
Complete the following statement. Aerodrome Surface Movement Radar operates on frequencies in the (i) .......... band employing an antenna that rotates at approximately (ii.......revolutions per minute; it is (iii) ......... possible to detect aircraft type.
(i) SHF (ii) 60 (iii) sometimes
Which of the following types of radar systems is most suited for short-range operation?
primary continuous wave
Considering a primary radar system, what kind of aerials are used?
One directional antenna both for transmitting and for receiving
In relation to radar systems that use pulse technology, the term 'Pulse Recurrence Rate (PRR)' signifies the
number of pulses per second => km = 300'000 km/s / PRR * 2
The minimum range of a primary radar, using the pulse technique, is determined by the (i)........ ; the maximum unambiguous range by the (ii)..........
(i) pulse length (ii) pulse recurrence frequency
Which one of the following statements is correct concerning the use in primary radar of continuous wave transmissions as compared with pulse transmissions?
It eliminates the minimum target reception range (Empfangsentfernung)
ILS has ?
LLZ (Localizer) GP (Glidepath) Marker and monitoring stations
LLZ: Frequenz? Ort? identification ?
300m behind the departure end of the ray; 108.00 - 111.975 ==> Only decimals ==> two or three letters of Morse code => A2A when morse and A9 when a combination of voice
LLZ: DDM
Difference in Depth Modulation => 2 Antennen an der Seite => Two signals are transmitted besides the carrier frequency => one 90 Hz the other 150 Hz ==> Merken wenn Aircraft nicht auf centerline ist => a difference in depth of modulation => deviation bar
LLZ: minimas
the coverage signal: Min. 25 NM and 10 Grad to teh left and right of teh extended runways centerline
Up to a distance of 17 NM: 35 to left and right
=> outside this range the localizer needle may be centered without on the localizer
LLZ: full deflection by teh deviation bar?
2.5 Grad to each side ( 2450 m between LLZ: antenna and threshold)
LLZ: CDI Back-Beam Approach
150 hz modulation applies to the left hand side and the 90 Hz to the right hand side ==> Fly away from the needle
GP: Ort? Frequenz?
1000 fet (300m) behind the threshold and 500 ft (150m) displaced from the centerline ; UHF => 328.6 MHz to 335.4 MHz => not published in the AIP O> coordinated with the published LLZ frequencies
GP: Grundprinzip and minima
a similar way, the 90 Hz modulation dominate date upper lobe while the 150 Hz modulation the lower lobe => min of 10 NM and 8 Grad to the left and right ==> In the vertical: 0.45 times to 1.75 times the nominal glide path angle
As the GP antenna is not located on teh rwy, glide path guidance is not possible all the way down to the ground or belows antenna height => Höhe ?
50 ft ==> Cat III jedoch bis zum touchdown
GP: Full deflection of the Instrument (HSI oder CDI) by teh glide path?
+/- 0.7 degrees for a nominal GP angle of 3 degrees
Marker Bacon: was? Frequen?
transmit a radio signal directly overhead a specific position => 75 MHz
Marker Bacon: Arten
Fan marker (FM): = >used by ILS
Zero marker: above NDB stations to fill out the cone of confusion
3 Arten marker beacon used in combination with ILS
OM (Outer Marker): between 4-7 Nm => 5 NM => 250 feet from either side extended rwy ==> Morse-style dashes (400Hz) = blue
MM (Middle Marker): 0.5 - 0.8 NM ahead of the rwy threshold => 250 feet from either side => morse dashes and dots (Punkte) (1300 HZ) = amber
IN (Inner Marker): imminent arrival at teh rwy => 100 ft from eitehr side => morse dots (3000 HZ) = weight
Grundfehler beim localizer
selbe wie beim VOR => Bend amplitude and scalopping
Weitere Fehler bei der ILS
Beam noise: radio beams affected by disturbance on their wys through teh atmosphere
Vehicles or other Aircrafts: signal interference by either surface vehicles or other aircrafts
Snow and Heavy Rain: a change in the diectional radio pattern of the glide slope signal
FM Broadcast Signal just below 108 MHz: => filters
Which principle is used by localizer measurements ?
Difference in Depth of Modulation (DDM)
What happens during a localiser approach when teh aircraft deviates from the extended centerline of the approached runways towards the right
The Difference in Depth of Modulation increases linearly from zero to 0.155 within the proportional zone
Consider teh non-approach side of an ILS installation. Which statement describes teh use of teh back bam correctly
The back beam may be utilized for a Non-precision Approach with reversed indications
(MLS): Was ist das?
Microwave landing system: Satellite systems (GPS etc.) in combination withe augmentation systems are expected to replace the ILS
Microwave landing system (MLS): Grundprinzip , Frequenz
Send a S-band from 5031 - 5091 MHZ => SHF ==> swept it across the coverage area at a fixed scan rate (To and FRO scans) => measuring the time between the received signals (hits) the airborne receiver is able to calculate its relative position
==>==> If the TO time and FRO time is teh same, teh aircraft is on the centerline
Microwave landing system (MLS): consist aus?
an approach station, a back approach or missed approach station, an elevation 1station (GP) and an elevation 2 station (flare guidance) and a standard DME
Microwave landing system (MLS): Was ist gegenpber der ILS besser?
1. parallel, segmental and curved approaches to the rwy
2.expanded coverage
3. higher guidance accuracy
4. less sensitive to weather, obstacles
5. no interference problems (FM radio)
6. digital data link
Microwave landing system (MLS): minimas coverage
+/- 40 degrees azimuth 0.9 - 15 Elevation
Microwave landing system (MLS): curved approach was braucht es
to allows for segmented and curved approaches a computer (FMS) and a database are requires as well in order to compare the actual position to the programed approached trajectory == >multi Mode Receiver (MMR)
Microwave landing system (MLS): If one wants to replace an ILS with an MLS and limits the operation to the standard ILS straight in approach ==> one can manage the installation without a
DME-P => the respective on-board indications are similar to ILS indications
